COMCRAZY Development Center

The Journey of Anet A8 Part 2 - Upgrades & Mods

2018-12-29T08:38:00.001-08:00

Identify, study and solving the issues always is an enjoyment for me. As in my first print of the 3DBenchy that shown in the previous post - The Journey of Anet A8 Part 1 - Setup & Stock Printing, I knew my printer is not optimized.

This post records all my journey on the upgrades, mods, tuning I had done at my printer.

General Reading

Below are few links as my kickstart on 3D printing and Anet A8

Slicing Software

Initially, I use the slicing software bundle with Anet A8, Cura version 14.0.7. For basic printing, this software is okie. I downloaded the latest Cura at that point of time - Cura 3.5.0 and of course the Anet A8 profile share by the netizen on the optimize configuration. In addition, create a new profile for PLA 1.75mm filament as Cura default is 3mm filament for PLA.

However, I face a serious under extrusion on the printing. After having a few tries on tuning and diagnosing, I revert to back Cura 14.0.7.

Within one month, Cura release version 3.6.0, as my suspicion on the under extrusion issue is a software issue, I downloaded the latest version and try again. It works perfectly just by using its default printing profile. I am happy with this current version

A8 Profile

Below are the profile I set for my stock Anet A8 printer

Start G-code

;Sliced at: {day} {date} {time}
G21 ;metric values
G90 ;absolute positioning
M82 ;set extruder to absolute mode
M107 ;start with the fan off
G28 X0 Y0 ;move X/Y to min endstops
G28 Z0 ;move Z to min endstops
G29
G0 X0 Y15 F9000 ; Go to front
G0 Z0.15 ; Drop to bed
G92 E0 ; zero the extruded length
G1 X40 E25 F500 ; Extrude 25mm of filament in a 4cm line
G92 E0 ; zero the extruded length
G1 E-1 F500 ; Retract a little
G1 X80 F4000 ; Quickly wipe away from the filament line
G1 Z0.3 ; Raise and begin printing.

End G-Code

;End GCode
M104 S0 ;extruder heater off
M140 S0 ;heated bed heater off (if you have it)
G91 ;relative positioning
G1 E-1 F300 ;retract the filament a bit before lifting the nozzle, to release some of the pressure
G1 Z+0.5 E-5 X-20 Y-20 F{travel_speed} ;move Z up a bit and retract filament even more
G28 X0 Y0 ;move X/Y to min endstops, so the head is out of the way
M84 ;steppers off
G90 ;absolute positioning

Above G-Code is provided by ianchen06, the start g-code include purge and nozzle wipe, this is very helpful to ensure the nozzle is clean before start printing.

PLA 1.75mm Filament Profile

Hardware Upgrades & Modes

Glass bed
Auto Bed Leveling Sensor - 3D Touch
Fan Duct
Extruder Button
Mosfet
Power Supply
T corner & Anti Z Wobble
Filament Guide
Spool Holder
Darth Vader Pop Figure

1. Glass bed

Glass bed is a very useful upgrade, easy to clean, easy to stick and is cheap. Refer to my previous post for detail (The Journey of Anet A8 Part 1 - Setup & Stock Printing)

2. Auto Bed Leveling Sensor - 3D Touch

Manual bed levelling always is a pain as you will need to repeat this after a few prints especially fail print that affects the bed and Z axis.

So my first investment is auto bed levelling sensor, I choose a clone version of BLTouch from China for testing purposes - 3DTouch that cost me MYR50.

Installation of the BLTouch / 3DTouch is not so straightforward but is worth it. You will need some electronic and soldering knowledge. I will advise you finish below two videos before you decide to go for this upgrade. Good Luck!

Installation

This video is a good reference for installation of BLTouch for Anet A8. For bracket, I use this design.

Firmware Upgrade

This video is a good reference for firmware configuration, compilation and installation.

Calibrating Z-Offset With An Auto Bed Levelling Probe

Yup, this upgrade is no magic, you still need to do the calibration of Z-Offset. This video is a good reference as the starting point

3. Fan Duct

The stock fan duct is not efficient, it didn't manage to cool down the filament fast enough. After few tries, this fan duct work well for me - "Spriya" - High Efficiency Anet A8 Fan Duct . Just remember to tune your heater using PID Auto Tune after installing the fan duct.

4. Extruder Button

A must have and is good for the test print. I use this design.

5. Mosfet

For your safety, I only upgrade the heated bed. Get it from Lazada and cost me MYR10. The bracket I use this design.

6. Power Supply

A should have upgrade. I burst the stock power supply (refer to my previous post). So I get a 300W power supply with a fan. A little bit noisy as there is a fan but for safety, I can take it.

7. T corner & Anti Z Wobble

Lot's of forum and comment recommended these two upgrades, as I don't have any jerking issue, I made this set of upgrade the last. Why I still go for this set of the upgrade? As screw and nut will lose on mechanical activity, putting this on will definitely reduce the jerking and give better stability.

9. Filament Guide

More organize, specially with spool holder. I enhance the filament guide from this design in order to work well with the spool holder.

9. Spool Holder

Save some space, more organized, smooth filament delivery. Is a must-have upgrade in my opinion. I am using this design. This upgrade uses lots of filament and I managed to print it with stock A8.

10. Darth Vader Pop Figure

Last, a Darth Vader pop figure. What the purpose?? Decoration and a detector for jerking of my printer!!

Some of my print

As shown below, I had printed a sword for my boy, the Elucidator from Sword Art Online (Thingiverse). There are a lot of defects like precision, print edges are bending (Warping), and others as this is printed with stock printer without any upgrade except the power supply and glass bed.

My first consider successful 3DBenchy

The Hulk - first print with the support structure.

Baby Groot - Wood PLA filament

The Journey of Anet A8 Part 1 - Setup & Stock Printing

2018-10-28T17:33:00.000-07:00

After 1 years of dragging, finally i brought a 3D printer. As the engineer, maker and beginner, I had chose a DIY and cheapest 3D printer I can get in market - Anet A8 which cost me USD 145/= together with 1 Kg of white PLA filament.

This post will record first month of my experience with Anet A8 start with setting up hardware to printing experience.

Un-boxing and Verify Received Goods

I brought this 3D printer from China seller via Lazada. Package arrived in good condition. In the box, there is a microSD card and USB card reader.

English version of installation manual provided in the SD card. Cross check and all parts is included.

The pain part, all acrylic board is protected by sticker on both side, removing them is tedious and time consuming job. If you just done your manicure, get someone to do it for you.

Setting Up the 3D Printer

Basically the manual is pretty clear and easy to follow and they do included a YouTube link (which i refer when i am stuck).

Following is the progress of my installation.

However, there are few points I will share here which for me is not clear or the silly mistake I made when setting up the 3D printer.

Motors Position

For Y-Motor, the connector should face frontward, not downward or upward. (pg.12 Assembly Step 3)
For both Z-Motors, the connectors should face backward, as you can see mine is facing front. (pg 21 Assembly Step 12 )

Y Axis Belt

The belt should tighten in the between of two belt fixation clamp, not next to the metal plate. (pg 19 Assembly Step 10)

Alignment of T Lead Screw, Elastic Coupling and Z Motor

This is most unclear part for me, check this link to get the idea. https://3dprint.wiki/reprap/anet/a8/coupler
After try and error, end up the two elastic couplings level alignment must be same.

Power Supply

The power supplied is not auto detect the voltage, you have to choose 110v or 240v by adjusting a switch.
As the printer is from China, the switch is set to 110v by default and I didn't release it. Bet you know what happen next, sparks and burn, say bye bye to the power supply.
I get a new one with max load as 300w, the most important feature for the new power supply is it got a fan attached to it. This is very important if you get a new power supply, as there are many case power supply overheated and cause fire.

Calibration

Once my Anet A8 power up successfully, next will be calibration. Specially the Z axis calibration.

Warped Heat bed

While calibrating my Anet A8, I found out that the heatbed is not flat (warped) with curve downward 2mm in the middle.
While waiting feedback from the seller, I just get a 2mm glass panel with size 220mm x 220mm x 2mm as suggested from forum which cost me less than USD2.50
However, 220mm x 200mm will block the heatbed screw, this will made calibrating a challenging job. I will suggest 200mm x 200mm or shown below but need custom glass cutting service and cost more.
How to make the glass stick on the heat bed? The easiest and cheapest solution and widely share in forum, get four wooden cloth pegs and get the spring in the middle then use your imagination.

Calibrating Z Axis

I know, using A4 paper to ensure 0.2mm space between heat bed and nozzle. But calibrating process is tedious and keep repeating.
What I did is first ensure left side is calibrated using the A4 paper method. Then for the rest of the side, I just use level ruler to made sure four side is at same level.
Then use A4 paper to verified as the final steps. I found this way is faster and more precise.

3D Printer Profile

I used Cura software and 3D printer profile provided in the SD Card with slight modification as shown below

Printing Temperature: 190 Celsius
Bed Temperature: 75 Celsius
Initial layer thickness (mm): 0

I found above configuration help the prints have better stickiness to the glass bed and have quality print. However, I believe the temperature is depend on environment too (I am in tropical country with average temperature of 30 Celsius), so test it yourself.

Printing

Adhesive, Adhesive & Adhesive - Why not sticking

The prints always cannot stick on the heat bed or glass bed till end of the print. Specially the heat bed touching area is small.
There are lots of suggestion using difference type of glue to help on this. My personal preference is using carpenter glue (white color glue).
Before printing start, I will spread a thin layer of glue on the glass heat bed.
Then in the middle of printing, pause the printing, then I will use syringe to put more glue around the prints and let it dry.
As the carpenter glue is water soluble, you can wash the print with water to clean the dried glue.

Sample Prints

Following is the some 3D print I made so far, is not perfect and I am still learning how to made it right

Guide & Upgrades

There are plenty of site sharing the must have upgrade for Anet A8, below are some reference

Summary

I had spent 2 weeks in order to complete the setup and calibrating but is worth it. Anet A8 is a good choice by compare the quality and the price. All you need is patient and time.

mBlock 3 Arduino Extension for 2-Wheel Robot Car

2018-04-12T07:33:00.006-07:00

This project is for 9 year old students to able to program this robot car. It uses mBlock (Scratch-based) with drag-and-drop programming.

We are introducing robotics and programming to 9 year old primary students with extreme budget constraint. With some research, we managed to come up with this solution. I will hereby share the material and idea behind this project.

mBlock 3 is built based on Scratch 2.0. Scratch is a programming tools for kids; it allows kids to program code by dragging and dropping the "blocks". mBlock enhances Scratch to allow it to talk to Arduino.

What I had done was build an extension for mBlock 3 with predefined parameters to allow the kids to instruct the robot car to move or play music.

Detailed instruction is included, click here for detail.

Workspace Environment Monitor - enVMon

2018-04-12T07:30:00.003-07:00

Ever care about the place you may spend one-third of a day? enVMon captures noise level, air quality, UV level, temperature and humidity.

This monitoring station will monitor the Ultra-Violet and sound level, temperature, humidity and air quality (CO2). All the above parameters are the common factors for a safe working environment.

The objective of this project is to place this monitoring station in the working environment and monitor it, compare the data and send notifications when the parameters reach the threshold.

Detail of the project is at here.

Susurri - The Secret Message Service

2016-10-31T21:07:00.003-07:00

Susurri is a working prototype that I had build for TADHack 2016 Kuala Lumpur. By utilizing the Cisco Tropo service to create a platform to let people leave a message with password protected. Then others can retrieve and listen to the message as long as they have the password.

Below is the one-page slide that I had shared in the TADHack presentation.

Tropo can support multiple programming languages, from Groovy, JavaScript, PHP, python to Ruby. For this prototype, PHP is used and since is using demo account, SIP is used for testing and demo. A gentle reminder on Tropo service, it support wide range of country but not all, Malaysia is one of the country which Tropo not supported.

Hereby I will share the code for Susurri, hope you enjoy your hacking on Tropo!

Tropo Script

<?php
/*********************************
 * Configuration
 *********************************/
$GETSESSIONEP="http://FQDN/v3/getsession.php";
$UDPATERECORDEP="http://FQDN/v3/updateRecord.php";
$SEARCHRECORDEP="http://FQDN/v3/searchRecord.php";
$RECORDFTPBASEURI="ftp://FQDN/";
$RECORDUSER="records@FQDN";
$RECORDPASSWORD="secret";
$RECORDHTTPBASEURI="http://FQDN/records/";

/*********************************
 * Variable
 *********************************/
$revision=48;
$menuResult = 0;
$numberOfRetry = 3;
$passcode = 0;
$recordId = 0;
$recordFileName="";
$callerId=$currentCall->callerID." [".$currentCall->callerName."]";


/*********************************
 * Logic
 *********************************/

// Asking user for action, create a message or listen to message
$menuResult = ask("Welcome to susurri ".$revision."! May I help you? Press 1 for creating a secret message, press 2 for listening to the secret message.", 
    array("choices" => "1,2", 
        "timeout"=>5.0, 
        "mode"=>"dtmf", 
        "attempts"=> $numberOfRetry, 
        "onBadChoice" => "badChoiceFCN")
);


if ($menuResult->value==1) { //Create message

    // Create an record in DB
    $getSessionRespJson = myCurl($GETSESSIONEP);
    $getSessionRespArry = json_decode($getSessionRespJson,true);
    
    // Check for error
    if ($getSessionRespArry['id'] != 'error') {
        $recordId = $getSessionRespArry['id'];
        $recordFileName = $recordId.".wav";
        
        say("Please start to speak your message after the beep sound.");
        
        // Record user voice 
        record("Please press the hash key to stop recording.", array(
            "beep"=>true,
            "terminator"=>"#",
            "asyncUpload"=>true,
            "maxTime"=>60,
            "recordURI"=>$RECORDFTPBASEURI. $recordFileName,
            "recordPassword"=>$RECORDPASSWORD,
            "recordUser"=>$RECORDUSER
       ));
       
       // Ask for password  
       $passcodeResult = ask("Please provide 5 digits passcode for your message.", 
            array("choices" => "[5 DIGITS]", 
                "timeout"=>5.0, 
                "mode"=>"dtmf", 
                "attempts"=> $numberOfRetry, 
                "onBadChoice" => "badChoiceFCN")
        );    
        
        $passcode = $passcodeResult->value;

        // Update DB record
        $getUpdateRespJson = myCurl($UDPATERECORDEP."?id=".urlencode($recordId).
            "&passcode=".urlencode($passcode)."&soundfilename=".urlencode($recordFileName).
            "&callerid=".urlencode($callerId));
            
        $getUpdateRespArry = json_decode($getUpdateRespJson,true);
        
        // Check for update status
        if ($getUpdateRespArry['result'] == 'success') {
            say("Your record ID is ".$recordId. " and passcode is ");
            // Speak by digit by digit rather as whole numeric
            say_as($passcode,"digits");
        } else {
            say("Internal error on case 4");
        }
        
    } else { // If error
        say("Internal error on case 3");
    }
    
} else if ($menuResult->value==2) { // Listen to a message

    // Asking user for passcode
    $listenPasscodeResult = ask("You have choose to listen a secret message, please enter 5 digits passcode.", 
        array("choices" => "[5 DIGITS]", 
            "timeout"=>5.0, 
            "mode"=>"dtmf", 
            "attempts"=> $numberOfRetry, 
            "onBadChoice" => "badChoiceFCN")
    );    
    $listenPasscode = $listenPasscodeResult->value;
    
    say("You have provide the passcode as ");
    // Speak by digit by digit rather as whole numeric
    say_as($listenPasscode,"digits");
    
    
    // Search for recording from database
    $searchRecordRespJson = myCurl($SEARCHRECORDEP."?passcode=".urlencode($listenPasscode));
    $searchRecordRespArry = json_decode($searchRecordRespJson,true);  
    
    if ($searchRecordRespArry['result'] == 'found') { // If found, playback the recording
        say("Message will start play in 2 seconds.");
        wait(2000);
        say($RECORDHTTPBASEURI.$searchRecordRespArry['soundFile']);
    } else if ($searchRecordRespArry['result'] == 'notfound') {
        say("Message with provided passcode not found.");
    } else {
        say("Internal error on case 5");
    }
    
} else {
    say("Internal error on case 2");
}

say("Thank you for using Susurri.");
wait(1000); 

/*********************************
 * UTILS
 *********************************/

// Call back function if user input is not recognize
function badChoiceFCN($event) {
    say("Sorry, your input is not recognize.");
}

// Speak by digit by digit rather as whole numeric
function say_as($value, $type) {
    $ssml_start = "<?xml version='1.0'?><speak>";
    $ssml_end="</say-as></speak>";
    $ssml ="<say-as interpret-as=\"vxml:$type\">$value";
    $complete_string = $ssml_start . $ssml . $ssml_end;
    say($complete_string);
}

// CURL
function myCurl($url) {
    //  Initiate curl
    $ch = curl_init();
    // Disable SSL verification
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
    // Will return the response, if false it print the response
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    // Set the url
    curl_setopt($ch, CURLOPT_URL,$url);
    // Execute
    $response=curl_exec($ch);
    // Closing
    curl_close($ch);
    
    return $response;
}
?>;

Server Side Script

base.php - Establish DB connection

<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "susurri";

// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn-&gt;connect_error) {
    die("Connection failed: " . $conn-&gt;connect_error);
} 

?>;

getsession.php - Create a record in database and return id

<?php
include 'base.php';

$sql = "INSERT INTO records (createdBy)
VALUES ('admin')";

if ($conn->query($sql) === TRUE) {
    echo "{\"id\":\"". $conn->insert_id."\"}";
} else {
    echo "{\"id\":\"error\"}";
}

$conn->close();

?>;

searchrecord.php - Search record in database

<?php
include 'base.php';

$passcode=$_REQUEST['passcode'];

$sql = "SELECT soundFile FROM records WHERE passcode=".$passcode;

$result =$conn->query($sql);


if ($result->num_rows > 0) {
 while($row = $result->fetch_assoc()) {
  echo "{\"result\":\"found\", \"soundFile\":\"".$row["soundFile"]."\"}";
  break;
 }
} else {
 echo "{\"result\":\"notfound\"}";
}


$conn->close();
?>;

updaterecord.php - Update record in database

<?php
include 'base.php';

$id=$_REQUEST['id'];
$passcode=$_REQUEST['passcode'];
$soundFilename=$_REQUEST['soundfilename'];
$callerId=$_REQUEST['callerid'];


$sql = "UPDATE records SET passcode=\"".$passcode."\", soundFile=\"".$soundFilename."\", callerId=\"".$callerId."\"  WHERE id=".$id;

if ($conn->query($sql) === TRUE) {
    echo "{\"result\":\"success\"}";
} else {
    echo "{\"result\":\"fail\"}";
}

$conn->close();
?>;

schema.sql - Database schema

CREATE TABLE IF NOT EXISTS `records` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `createdAt` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `createdBy` varchar(255) DEFAULT NULL,
  `passcode` varchar(20) DEFAULT NULL,
  `soundFile` varchar(255) DEFAULT NULL,
  `callerId` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `passcod` (`passcode`)
) ENGINE=MyISAM

Tool for encode, decode and formatter for common use data

2015-06-30T20:57:00.000-07:00

After long 4 years, finally get a technical oriented job again. No more manager but solution architect. In this post I will share a web tool able to below task

Hex - Ascii Converter
Base64 encoder and decoder
BCD encoder and decoder
ASN.1 Decoder
XML Formatter
JSON Formatter
CSS Formatter
SQL Formatter

Hereby is the link J.Dencoder

Password-less SSH Authentication Validation

2012-01-11T16:16:00.000-08:00

Password-less SSH login is widely use inside a trusted network. System administrator will use this method to remotely execute some task specially in a batch scripting. However, this method sometime may failed in certain circumstances for example host name change, accidentally remove the public key or private key or run the script using different user.

So validation and alerting is very important on Password-less SSH Authentication. Hereby is the script to perform validation, it has been tested on RHEL and CentOS.

Setup
1. tester1 account is configured to have SSH RSA password-less login from comcrazy account
2. tester2 account have NO password-less login from comcrazy account

Test Script
[comcrazy@localhost ~]$ ssh -qo BatchMode=yes tester1@localhost.localdomain echo OK |grep OK |wc -l
1
[comcrazy@localhost ~]$ ssh -qo BatchMode=yes tester2@localhost.localdomain echo OK |grep OK |wc -l
0

Result
By using above command, if the remote account IS NOT configured as SSH password-less authentication or password-less authentication is not working, then it will return 0. Otherwise, this command will return a 1 as result.

Project Euler and Me

2011-12-14T13:00:00.000-08:00

Thanks to Ailin and Adam that introduce me the Project Euler and now I am totally addicted with it. After 8 years not using C as my primary programming language, is time for me to pick it up and do something with C ideology - small footprint with great performance!

Below is the question from Project Euler and the code I had written to solve it. Feel free to download them then make it better or give comment and suggestion on the solution. Programmer ROCKS!

ID	Description / Title	Solutions
1	Add all the natural numbers below one thousand that are multiples of 3 or 5.	Link
2	By considering the terms in the Fibonacci sequence whose values do not exceed four million, find the sum of the even-valued terms.	Link
3	Find the largest prime factor of a composite number.	Link
4	Find the largest palindrome made from the product of two 3-digit numbers.	Link
5	What is the smallest number divisible by each of the numbers 1 to 20?	Link
6	What is the difference between the sum of the squares and the square of the sums?	Link
7	Find the 10001st prime.	Link
8	Discover the largest product of five consecutive digits in the 1000-digit number.	Link
9	Find the only Pythagorean triplet, {`a`, `b`, `c`}, for which `a` + `b` + `c` = 1000.	Link
10	Calculate the sum of all the primes below two million.	Link
11	What is the greatest product of four adjacent numbers on the same straight line in the 20 by 20 grid?	Link
12	What is the value of the first triangle number to have over five hundred divisors?	Link
13	Find the first ten digits of the sum of one-hundred 50-digit numbers.	Link
14	Find the longest sequence using a starting number under one million.	Link
15	Starting in the top left corner in a 20 by 20 grid, how many routes are there to the bottom right corner?	Serial Parallel
16	What is the sum of the digits of the number 2¹⁰⁰⁰?	Link
17	How many letters would be needed to write all the numbers in words from 1 to 1000?
18	Find the maximum sum travelling from the top of the triangle to the base.	Link
19	How many Sundays fell on the first of the month during the twentieth century?
20	Find the sum of digits in 100!	Link
21	Evaluate the sum of all amicable pairs under 10000.
22	What is the total of all the name scores in the file of first names?	Link
23	Find the sum of all the positive integers which cannot be written as the sum of two abundant numbers.	Link
24	What is the millionth lexicographic permutation of the digits 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9?	Link
25	What is the first term in the Fibonacci sequence to contain 1000 digits?	Link
26	Find the value of d < 1000 for which 1/d contains the longest recurring cycle.	Link
27	Find a quadratic formula that produces the maximum number of primes for consecutive values of n.	Link
28	What is the sum of both diagonals in a 1001 by 1001 spiral?	Link
29	How many distinct terms are in the sequence generated by a^b for 2 = a = 100 and 2 = b = 100?	Link
30	Find the sum of all the numbers that can be written as the sum of fifth powers of their digits.	Link
31	Investigating combinations of English currency denominations.	Link
32	Find the sum of all numbers that can be written as pandigital products.	Link
33	Discover all the fractions with an unorthodox cancelling method.	Link
34	Find the sum of all numbers which are equal to the sum of the factorial of their digits.	Link
35	How many circular primes are there below one million?	Link
36	Find the sum of all numbers less than one million, which are palindromic in base 10 and base 2.	Link
37	Find the sum of all eleven primes that are both truncatable from left to right and right to left.	Link
38	What is the largest 1 to 9 pandigital that can be formed by multiplying a fixed number by 1, 2, 3, ... ?	Link
39	If p is the perimeter of a right angle triangle, {a, b, c}, which value, for p = 1000, has the most solutions?	Link
40	Finding the n^th digit of the fractional part of the irrational number.	Link
41	What is the largest n-digit pandigital prime that exists?	Link
42	How many triangle words does the list of common English words contain?	Link
43	Find the sum of all pandigital numbers with an unusual sub-string divisibility property.	Link
44	Find the smallest pair of pentagonal numbers whose sum and difference is pentagonal.	Link
45	After 40755, what is the next triangle number that is also pentagonal and hexagonal?	Link
46	What is the smallest odd composite that cannot be written as the sum of a prime and twice a square?	Link
47	Find the first four consecutive integers to have four distinct primes factors.	Link
48	Find the last ten digits of 1¹ + 2² + ... + 1000¹⁰⁰⁰.	Link
49	Find arithmetic sequences, made of prime terms, whose four digits are permutations of each other.	Link
50	Which prime, below one-million, can be written as the sum of the most consecutive primes?	Link

Problem 15

Using programmatic method with serial navigating technique take 2 hours 15 minutes to get the result. If using mathematical method to calculate the possible path only take less then 1 second. The difference between these two methods is mathematical method only projected how many path there are but programmatic method give the actual path it had been navigated.

In my opinion, the real world problem like solving maze or path finding, programmatic method is more realistic. However, mathematical method can help to pre-project the result. The next thing I will going to do is design a parallel path navigating technique using multi-thread with multiple navigator, this solution will combine both mathematical and programmatic method to accomplish the objective.

Result

Problem 15 with Serial Navigating Solution
-------------------------------------------
Path for 1x1. P: 2 (0s 2ms), M: 2 (0s 381ms)
Path for 2x2. P: 6 (0s 2ms), M: 6 (0s 11ms)
Path for 3x3. P: 20 (0s 4ms), M: 20 (0s 12ms)
Path for 4x4. P: 70 (0s 9ms), M: 70 (0s 12ms)
Path for 5x5. P: 252 (0s 50ms), M: 252 (0s 13ms)
Path for 6x6. P: 924 (0s 101ms), M: 924 (0s 13ms)
Path for 7x7. P: 3432 (0s 370ms), M: 3432 (0s 16ms)
Path for 8x8. P: 12870 (0s 1479ms), M: 12870 (0s 16ms)
Path for 9x9. P: 48620 (0s 5363ms), M: 48620 (0s 21ms)
Path for 10x10. P: 184756 (0s 18646ms), M: 184756 (0s 15ms)
Path for 11x11. P: 705432 (0s 40020ms), M: 705432 (0s 17ms)
Path for 12x12. P: 2704156 (0s 167027ms), M: 2704156 (0s 17ms)
Path for 13x13. P: 10400600 (0s 587571ms), M: 10400600 (0s 19ms)
Path for 14x14. P: 40116600 (3s -715159ms), M: 40116600 (0s 20ms)
Path for 15x15. P: 155117520 (8s 773356ms), M: 155117520 (0s 19ms)
Path for 16x16. P: 601080390 (36s -370565ms), M: 601080390 (0s 81ms)
Path for 17x17. P: 2333606220 (138s 83071ms), M: 2333606220 (0s 104ms)
Path for 18x18. P: 9075135300 (546s -580371ms), M: 9075135300 (0s 68ms)

Path for 19x19. P: 35345263800 (2104s 60565ms), M: 35345263800 (0s 44ms)

Path for 20x20. P: 137846528820 (8236s 7101ms), M: 137846528820 (0s 40ms)

FORM validation with jquery.ajax

2011-12-09T05:51:00.001-08:00

When <FORM> validation meet the JQUERY.AJAX

Below are the basic <FORM> with validation before the form submitted.

1 <script>
2 function validateform() {
3 $.ajax({
4 type: "POST",
5 url: "/country/checkcountry",
6 data: "code="+countrycode+"&name="+countryname,
7 dataType: 'json',
8 success: function (data, status) {
9 if (data.result != 'OK') {
10 console.log('check ok');
11 return false
12 } else {
13 console.log('check not ok');
14 return true
15 }
16 },
17 error: function (data, status) {
18 console.log('check error')
19 return false
20 }
21 });
22 console.log('should never show');
23
24 return false; //For testing purpose, it should be return true
25 }
26 </script>
27
28 <FORM action="/country/addcountry" method="post" onsubmit="return validateform()">
29 ..........................
30 </FORM>

At the first glance, the java script seem logically fine. Actually, there are TWO major issue in that java script!

1. ASYNC issue

If we really make above code run-able, no matter what result we get from the ajax call, we will still get the "should never show" message at line 22 then follow by the console message from the ajax stub (10,13 or 18).

By default, jquery ajax is a asynchronous process. This means once the ajax triggered, browser will not wait until it complete but rather continue with the next task. For our case is the console.log at line 22.

This is not the result we want, specially a sequential validation activity. I order to solve this, we need to add a parameter to the ajax as shown below.

asycn: false,

2. Return operation in jquery ajax

After insert the async parameter to ajax, then let's try again. aiks... still cannot get the expected result, although by now the sequence of the log is correct. By now, we should get the console message  from the ajax stub (10,13 or 18) first then follow by message at line 22. But the function should not reach line 22, it should return at line 11, 14 or 19.

The catch is, jquery ajax execute their operation at another thread and not in the same scope with validateform function. The return operation in ajax only quit from it's own thread but not the function. In order to solve this, declare a boolean variable at the scope of validateform function then assigned the status and perform necessary action after the ajax task. See below code for complete solution.

1 <script>
2 function validateform() {
3 var validateResult = true;
4
5 $.ajax({
6 type: "POST",
7 url: "/country/checkcountry",
8 data: "code="+countrycode+"&name="+countryname,
9 dataType: 'json',
10 success: function (data, status) {
11 if (data.result != 'OK') {
12 console.log('check ok');
13 validateResult=false;
14 } else {
15 console.log('check not ok');
16 validateResult=true;
17 }
18 },
19 error: function (data, status) {
20 console.log('check error')
21 validateResult=false
22 }
23 });
24
25 return validateResult;
26 }
27
28
29 </script>
30
31 <FORM action="/country/addcountry" method="post" onsubmit="return validateform()">
32 ..........................
33 </FORM>

Conclusion
Ajax task may take some time to complete, if you using it at form validation specially submit validation, is recommended to show some indication to user to inform their action is under process.

Document.getElementById return null

2011-12-07T23:17:00.001-08:00

The problem
Document.getElementById() - The most useful and common use features while developing in javascript. Some how this function call will failed unexpected without any javascript error. The most common error for this function is returning a NULL even we can 100% confirm the element with correct ID is there!

The catch
Come on, this is not a browser issue nor javascript issue. There are few possible that trigger this issue. Listed below is what I faced before, if you have more please share by replying a comment. TQ.

1. ID had been used more than once in a HTML page
Check is the ID the element has been used more than once in a HTML. The most easier way to debug is right click on the web browser and click VIEW SOURCE (CTRL U). From there use the find tool to search for the ID that document.getElementById() cannot found.

2. Nested <FORM>
document.getElementById() return null while trying to get a <FORM> element? Make sure that the <FORM> element you try to get is not under another <FORM> element! This error is usually happen while using PHP framework or template based framework.

Try to move the inner <FORM> element out from the parent form. For Symfony PHP framework, sometime this is hard to archive because we are good programmer that make our code modular enough to screw ourselves up :P . In this case, you can use the SLOT concept in Symfony to solve this problem.

You know something is not listed here, please reply a comment to share. TQ.

Useful Coding Tools and JavaScript Libraries For Web Developers - Smashing Magazine

2011-10-30T17:40:00.000-07:00

Useful Coding Tools and JavaScript Libraries For Web Developers - Smashing Magazine:

'via Blog this'

Lessons From A Review Of JavaScript Code - Smashing Coding

2011-10-27T17:49:00.000-07:00

Lessons From A Review Of JavaScript Code - Smashing Coding:

'via Blog this'

Supporting Your Product: How To Provide Technical Support - Smashing Magazine

2011-10-11T00:40:00.000-07:00

Supporting Your Product: How To Provide Technical Support - Smashing Magazine:

'via Blog this'

Free Download: Cheat Sheet For Designing Web Forms - Smashing UX Design

2011-10-10T03:09:00.000-07:00

Free Download: Cheat Sheet For Designing Web Forms - Smashing UX Design:

'via Blog this'

Panes Freezer - The jquery plugin

2011-10-10T00:15:00.000-07:00

About

When working with large table, it gets a bit frustrating, when you go to read the data in a distant row or column and the headings at the top of the page or down the side of the sheet disappear.

If you are like me, you're never quite sure if you are looking in the right spot so you scroll back and forth trying to read first the heading and then the data, heading then the data, until you're almost sure you have it right.

To avoid this back and forth waste of time, use this jquery plugin. This plugin allows you to lock specific rows and columns so that they will always be visible on screen no matter how far you scroll to the right or down.

Idea of this plugin is no existing coding modification need to be done, just with additional <DIV> and call the plugin code shown below, that's all!


$('#mydiv_1_0').panesfreezer({

    'headerrow': 1,

    'headercolumn' : 1

});

Demo

Supported browser

Below table show the supported browser for this plugin

No	Browser	Version	OS	Support
1	Google Chrome	14.0.835.202 m	Windows 7	Y
2	Firefox	7.0	Windows 7	Y
3	Safari	5.1	Windows 7	Y
4	Internet Explorer	9	n/a	n

Links

jquery plugin page - http://plugins.jquery.com/project/panesfreezer
Github page - https://github.com/comcrazy/Panes-Freezer/
Author blog - http://comcrazy-devcenter.blogspot.com/ @ http://comcrazy.info/

MySQL Schema and Index Optimization Example

2011-10-06T02:57:00.000-07:00

Transaction logging is a essential activity for telco industry. These records are important to resolve customer dispute or technical support activity. This post will discuss about MySQL schema and index optimization on a table that store huge amount (20 Millions ++ per day in one table) of transaction record.

Gathered Information

1. Shown below is the table schema for the transaction log table.

CREATE TABLE `transactionlog` (
`datetime` varchar(45) NOT NULL DEFAULT '',
`version` int(10) DEFAULT NULL,
`category` varchar(45) DEFAULT NULL,
`src_acc_name` varchar(45) DEFAULT NULL,
`dst_acc_name` varchar(45) DEFAULT NULL,
`ib_msg_id` varchar(100) DEFAULT NULL,
`ob_msg_id` varchar(100) DEFAULT NULL,
`receiver_mpno` varchar(45) DEFAULT NULL,
`sender_mpno` varchar(45) DEFAULT NULL,
`country_code` varchar(5) DEFAULT NULL,
`operator_id` int(10) DEFAULT NULL,
`submitted_datetime` varchar(45) NOT NULL DEFAULT '',

----- WITH MORE COLUMNS ----

KEY `index1` (`submitted_datetime`(20),`category`),
KEY `index2` (`submitted_datetime`(20),`receiver_mpno`(20)),
KEY `index3` (`submitted_datetime`(20),`src_acc_name`,`category`),
KEY `index4` (`submitted_datetime`(20),`operator_id`),
KEY `index5` (`ib_msg_id`(25))
) ENGINE=MyISAM DEFAULT CHARSET=latin1

2. Shown below is the SQL that utilize above table that extract from code.

SELECT * FROM transactionlog
LEFT JOIN cfg.operator ON (transactionlog.operator_id = cfg.operator.operator_id)
LEFT JOIN cfg.country ON (transactionlog.country_code = cfg.country.country_code)
WHERE submitted_datetime >= '2009-09-10 20:00:00'
    AND submitted_datetime <= '2009-09-10 22:00:00'
    AND category IN ('Category 1', 'Category 2', 'Category 3') ORDER BY datetime ASC;

SELECT * FROM transactionlog
LEFT JOIN cfg.operator ON (transactionlog.operator_id = cfg.operator.operator_id)
LEFT JOIN cfg.country ON (transactionlog.country_code = cfg.country.country_code)
WHERE submitted_datetime >= '2009-09-10 20:00:00'
    AND submitted_datetime <= '2009-09-10 22:00:00'
    AND (receiver_mpno = '69012641245' OR sender_mpno = '69012641245')
ORDER BY datetime ASC;

SELECT * FROM transactionlog
LEFT JOIN cfg.operator ON (transactionlog.operator_id = cfg.operator.operator_id)
LEFT JOIN cfg.country ON (transactionlog.country_code = cfg.country.country_code)
WHERE submitted_datetime >= '2009-09-10 20:00:00'
    AND submitted_datetime <= '2009-09-10 22:00:00'
    AND (src_acc_name = 'carrier11' OR dst_acc_name = 'carrier11')
    AND category IN ('Category 1', 'Category 2', 'Category 3')
ORDER BY datetime ASC;

SELECT * FROM transactionlog
LEFT JOIN cfg.operator ON (transactionlog.operator_id = cfg.operator.operator_id)
LEFT JOIN cfg.country ON (transactionlog.country_code = cfg.country.country_code)
WHERE submitted_datetime >= '2009-09-10 20:00:00'
    AND submitted_datetime <= '2009-09-10 22:00:00'
    AND transactionlog.operator_id = 3366
ORDER BY datetime ASC;

SELECT * FROM transactionlog
LEFT JOIN cfg.operator ON (transactionlog.operator_id = cfg.operator.operator_id)
LEFT JOIN cfg.country ON (transactionlog.country_code = cfg.country.country_code)
WHERE submitted_datetime >= '2009-09-10 20:00:00'
    AND submitted_datetime <= '2009-09-10 22:00:00'
    AND (ib_msg_id = 'message03400123123413' OR ob_msg_id = 'message03400123123413')
ORDER BY datetime ASC;

Analysis and Solution

OK, let's start with table schema defination. Below are the few issues I spotted.

1. datetime & submitted_datetime

Problem
Both data type are varchar(45) which doesn't make sense. Why want to store date time information in a varchar rather than datetime datatype? Based on http://dev.mysql.com/doc/refman/5.0/en/storage-requirements.html, datetime datatype consume 8 bytes (current sue 46 bytes). In addition, perfomance on index creation and index filtering on datetime datatype definately faster than varchar.

Solution
Change the datatype to datetime.

2. Category as constant

Problem
After study the code, found out that categories is a set of constant string; wherelse in coding, those categories is identified by integer.

Solution
Change the datatype of category from varchar(45) to tinyint (3). Then another issue raise to me, data is insert into this table using select insert sql statement which the catogery of the source table also is a varchar. In order to solve this, I recommeneded to create a mysql procedure to map the string to an integer and use it at the select insert statement. Pro of this method is no code changes needed. Cons is if there are new category added, need to update the mysql procedure.

Next, let's look into index for this table. Below are the few issues I spotted.

3. Table index definition

Problem

From the provided sql, found out that ob_msg_id and dst_acc_name apear at where clause but it not exist in index.
From the provided sql, the query have a pattern which start from submitted_datetime then follow by other criteria. If that is the case, no need to create so many index to optimize the search filtering. With correct sequence, one index is enough, please refer to http://dev.mysql.com/doc/refman/5.0/en/multiple-column-indexes.html

Solution
Create a index as follow, Then modify the code that will generate the SQL statement where clause follow below index sequence.

KEY `index1` (`submitted_datetime`, `category`, `receiver_mpno`(20), `sender_mpno`(20), `src_acc_name`, `dst_acc_name`, `operator_id`, `ib_msg_id`(25), `ob_msg_id`(25), `datetime`) USING BTREE

Propose Solution Summary

Table Schema

CREATE TABLE `transactionlog` (
`datetime` datetime NOT NULL DEFAULT '',
`version` int(10) DEFAULT 0,
`category` tinyint(3) DEFAULT 0,
`src_acc_name` varchar(45) DEFAULT NULL,
`dst_acc_name` varchar(45) DEFAULT NULL,
`ib_msg_id` varchar(100) DEFAULT NULL,
`ob_msg_id` varchar(100) DEFAULT NULL,
`receiver_mpno` varchar(45) DEFAULT NULL,
`sender_mpno` varchar(45) DEFAULT NULL,
`country_code` varchar(5) DEFAULT NULL,
`operator_id` int(10) DEFAULT 0,
`submitted_datetime` datetime NOT NULL DEFAULT '',

----- WITH MORE COLUMNS ----

KEY `index1` (`submitted_datetime`, `category`, `receiver_mpno`(20), `sender_mpno`(20), `src_acc_name`, `dst_acc_name`, `operator_id`, `ib_msg_id`(25), `ob_msg_id`(25), `datetime`) USING BTREE

) ENGINE=MyISAM DEFAULT CHARSET=latin1

Select Statement

SELECT * FROM transactionlog
LEFT JOIN cfg.operator ON (transactionlog.operator_id = cfg.operator.operator_id)
LEFT JOIN cfg.country ON (transactionlog.country_code = cfg.country.country_code)
WHERE submitted_datetime >= '2009-09-10 20:00:00'
    AND submitted_datetime <= '2009-09-10 22:00:00'
    AND category IN (1, 2, 3) ORDER BY datetime ASC;

SELECT * FROM transactionlog
LEFT JOIN cfg.operator ON (transactionlog.operator_id = cfg.operator.operator_id)
LEFT JOIN cfg.country ON (transactionlog.country_code = cfg.country.country_code)
WHERE submitted_datetime >= '2009-09-10 20:00:00'
    AND submitted_datetime <= '2009-09-10 22:00:00'
    AND category IN (1, 2, 3)
    AND (src_acc_name = 'carrier11' OR dst_acc_name = 'carrier11')
ORDER BY datetime ASC;

Optimization Testing and It's Result

Environment

Platform: Virtual Machine 32bit
CPU: 1 core, Intel(R) Core(TM)2 Duo CPU T6670 @ 2.20GHz
Memory: 1024M
OS version : CentOS release 5.4 (Final)
Mysql version: Ver 14.14 Distrib 5.5.15, for Linux (i686) using readline 5.1
Mysql config: installation default

Result

Task (transactionlog table contain 20M records initially)	Before (s)	After (s)	Improvement (%)
Select insert 32K+ records and insert into transactionlog table	422.52	5.97	98.59%
Search by category	318.51	91.11	71.39%
Search by receiver/sender number	314.7	74.38	76.36%
Search by account name	326.67	96.09	70.58%
Search by operator id	327.49	79.79	75.64%
Search by message ID	319.46	86.92	72.79%

Conclusion

Bravo, the results generally are improve over 70%. As shown at the table above, more index (or separated index) doesn't mean better performance. It is very expensive to generate index, it hoc up CPU time and IO waiting time. Secondly, varchar is convenient but is very bad in indexing; slower and bigger size.

Javascript Multi-Dimension Array to JSON Converter

2011-09-08T01:29:00.000-07:00

The Problem
Lately ask by one of my programmer - How to pass a javascript multi-dimension array back to PHP? First thing strike in my mind, JSON.stringify! But after some quick reading and testing, found out that stringify does not support cyclic data structures.

Then brainstorming session begin. Why need to pass in multi-dimension array, why not this and why not that... And last, he just said "This is the way I want, can you make it happen or not?".

Thanks for his challenge, here by is the solution.

The Solution
Following code is tested with following scenario

string
numeric
fraction
boolean
\r\n

Is not yet fully comply to json specification yet but support most common use datatype. If anyone enhance this code, please do share. Thank you.

Associate Array

PHP json encode: {"first":["child1","node1",["subchidl1","subnode1"]],"second":{"0":"child2","1":"node3","new":true},"third":["child3",3,3.33,"a\r\n"],"forth":"child4"} (PHP json encode)

{"first":["child1","node1",["subchidl1","subnode1"]],"second":{"0":"child2","1":"node3","new":true},"third":["child3",3,3.33,"a\r\n"],"forth":"child4"} (multiDimensionArray2JSON)

Normal Array

PHP json encode: [["child1","node1",["subchidl1","subnode1"]],{"0":"child2","1":"node3","new":true},["child3","node3"],"child4"] (PHP json encode)

[["child1","node1",["subchidl1","subnode1"]],{"0":"child2","1":"node3","new":true},["child3","node3"],"child4"] (multiDimensionArray2JSON)

Not Array

PHP json encode: "not array" (PHP json encode)

"not array" (multiDimensionArray2JSON)

Masza

{"carrier0":["","10"],"carrier1":["10","10"],"0carrier":["","10"],"1carrier":["10","10"]} (PHP json encode)

{"carrier0":["","10"],"carrier1":["10","10"],"0carrier":["","10"],"1carrier":["10","10"]} (multiDimensionArray2JSON)

To download the test scrip, click here.

Path Finding in PHP

2011-08-18T19:34:00.000-07:00

Lately create a path finding algorithm example using PHP for my junior to refer. Hopefully this code will also benefit others who look for same solution.

Scenario
Have bunch of records which is in the tree structure with one entry point. Need to find all the possible path from entry point node until the leave node.

Following is the tree structure.

1
/ | \
/ | \
2 3 14
/ |
/ |
4 5
/ / \
/ / \
6 7 8
/ \
9 10
| /\
11 / \
/ | \ 12 13
/ | \ |
16 17 18 15

Expected Path:
ROUTE1:ROUTE2:ROUTE4:ROUTE6
ROUTE1:ROUTE3:ROUTE5:ROUTE7:ROUTE9:ROUTE11:ROUTE16
ROUTE1:ROUTE3:ROUTE5:ROUTE7:ROUTE9:ROUTE11:ROUTE17
ROUTE1:ROUTE3:ROUTE5:ROUTE7:ROUTE9:ROUTE11:ROUTE18
ROUTE1:ROUTE3:ROUTE5:ROUTE8:ROUTE10:ROUTE12:ROUTE15
ROUTE1:ROUTE3:ROUTE5:ROUTE8:ROUTE10:ROUTE13
ROUTE1:ROUTE14

Click here to Download.

Symfony Admin Generator Framework Skeleton

2011-05-28T08:30:00.000-07:00

Symfony is a very useful PHP framework, specially the admin generator features! Just define the database schema, run few command and without writing a single code (errr.... sort of) the basic CRUD (Create Read Update Delete) functionality is ready! In addition, table listing, search features (with filtering function) and batch action is there too! It's amazing and thanks to Symfony developer effort on this.

However, the output still lack of other essential features like

Site header and site footer
User authentication, user account, user permission and user group.
Menu system
and so on....

To complete the admin generator functionality, I had installed the most useful plugin published on Symfony web site and put some extra effort to make other useful features to this distribution.

Following is the extra features

A basic web design with site title at header and copyright statement with company name at footer. Configurable via siteconfig.
A pretty login screen
Drop down menu at header. Fully configurable with two level menu supported
Dynamic SMTP information that store in database, no extra code needed to use the info, just call the mailer will do. Configurable via siteconfig.
Dynamic timezone on site level (with minor enhancement, can be user level too). Database still store the date time in UTC but displayed to user using configured timezone. Configurable via siteconfig.
A simple send email form, able to send email based on the SMTP setting and each email is save to database too. HTML email support with tinyMCE use in mail composing form.
Better UI compare to default template provided by Symfony admin generator. Using jquery and ajax for search reload , pagination reload and overlay search box.
A nice interface for user, group and permission management.
Site Configuration tool (siteconfig) for admin to configure the parameter used by above features.

Following plugins is used in this distribution

symfony 1.4.11-stable
sfDoctrineGuardPlugin 5.0.0-stable
mpRealityAdminPlugin 0.9.4-beta
pmSuperfishMenuPlugin 1.0.1-stable
sfDatePickerTimePlugin 0.1.4-alpha
sfFormExtraPlugin 1.1.3-stable

Click here to Download.

PHP Pear Mail Test Kit

2011-05-13T21:44:00.000-07:00

Requested by the support team, I had build a PHP page that able to test the functionality of the PHP Pear Mail module.

The features included

Validate installation of PEAR
Validate installation of PEAR Mail module
Support all send mail options that supported by PEAR Mail - mail, direct sendmail, SMTP.
Enable or disable SMTP authentication.
Full validation on user input
ALL in a SINGLE file, easy to install.

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">

<HTML>
    <HEAD>
        <TITLE>PHP Pear Mail Test Tool</TITLE>
        <META NAME="Generator" CONTENT="TextPad 4.6">
        <META NAME="Author" CONTENT="comcrazy">
        <META NAME="Keywords" CONTENT="php pear mail test tool">
        <META NAME="Description" CONTENT="PHP Pear Mail test tool, support mail, sendmail and SMTP">

        <style type="text/css">
            .errormsg
            {
                color: red;
                font-weight: bold;
            }
            .notimsg
            {
                color: blue;
                font-weight: bold;
            }
        </style>

        <script type="text/javascript">
            // <![CDATA[

            function authChange()
            {
                if(document.getElementById('smtpAuth').checked)
                {
                    document.getElementById('emailUsername').disabled = false;
                    document.getElementById('emailPassword').disabled = false;
                    document.getElementById('emailUserRequired').style.display = "";
                    document.getElementById('emailPasswordRequired').style.display = "";
                }
                else
                {
                    document.getElementById('emailUsername').disabled = true;
                    document.getElementById('emailPassword').disabled = true;
                    document.getElementById('emailUsername').value = "";
                    document.getElementById('emailPassword').value = "";
                    document.getElementById('emailUserRequired').style.display = "none";
                    document.getElementById('emailPasswordRequired').style.display = "none";
                }
            }

            function validateForm()
            {
                var emailReg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;

                document.getElementById('fromEmailError').innerHTML = "";
                document.getElementById('toEmailError').innerHTML = "";
                document.getElementById('subjectError').innerHTML = "";
                document.getElementById('smtpserverError').innerHTML = "";
                document.getElementById('smtpportError').innerHTML = "";
                document.getElementById('emailUsernameError').innerHTML = "";
                document.getElementById('emailPasswordError').innerHTML = "";

                var errDetect = false;
                var notDataErrMsg = "Required.";
                var invalidEmailMsg = "Invalid email format";

                var fromEmail = document.getElementById('fromEmail').value;
                var toEmail = document.getElementById('toEmail').value;
                var subject = document.getElementById('subject').value;
                var emailContent = document.getElementById('emailContent').value;
                var smtpserver = document.getElementById('smtpserver').value;
                var smtpport = document.getElementById('smtpport').value;
                var emailUsername = document.getElementById('emailUsername').value;
                var emailPassword = document.getElementById('emailPassword').value;

                if (fromEmail.length == 0)
                {
                    document.getElementById('fromEmailError').innerHTML = notDataErrMsg;
                    errDetect = true;
                }
                else if(emailReg.test(fromEmail) == false)
                {
                    document.getElementById('fromEmailError').innerHTML = invalidEmailMsg;
                    errDetect = true;
                }

                if (toEmail.length == 0)
                {
                    document.getElementById('toEmailError').innerHTML = notDataErrMsg;
                    errDetect = true;
                }
                else if(emailReg.test(toEmail) == false)
                {
                    document.getElementById('toEmailError').innerHTML = invalidEmailMsg;
                    errDetect = true;
                }

                if (subject.length == 0)
                {
                    document.getElementById('subjectError').innerHTML = notDataErrMsg;
                    errDetect = true;
                }

                if (document.getElementById('mailerSMTP').checked)
                {
                    if (smtpserver.length == 0)
                    {
                        document.getElementById('smtpserverError').innerHTML = notDataErrMsg;
                        errDetect = true;
                    }

                    if (smtpport.length == 0)
                    {
                        document.getElementById('smtpportError').innerHTML = notDataErrMsg;
                        errDetect = true;
                    }
                    else if (!parseInt(smtpport) || parseInt(smtpport) <= 0 || parseInt(smtpport) > 65535)
                    {
                        document.getElementById('smtpportError').innerHTML = "Invalid port number, should between 1 - 65535";
                        errDetect = true;
                    }

                    if (document.getElementById('smtpAuth').checked)
                    {
                        if (emailUsername.length == 0)
                        {
                            document.getElementById('emailUsernameError').innerHTML = notDataErrMsg;
                            errDetect = true;
                        }

                        if (emailPassword.length == 0)
                        {
                            document.getElementById('emailPasswordError').innerHTML = notDataErrMsg;
                            errDetect = true;
                        }
                    }
                }

                return (errDetect == true? false : true);
            }
            // ]]>
        </script>
    </HEAD>

    <BODY>

        <H1 style="margin-bottom: 0;">PHP Pear Mail Tester</H1>
        <div style="margin-top: 0">by <a href="http://comcrazy-devcenter.blogspot.com/" alt="comcrazy development centre">comcrazy</a></div>

        <HR/>

        <?php
        include_once 'System.php';
        include_once 'Mail.php';
        if (class_exists('System', false))
        {
            if (!class_exists('Mail', false))
            {
                echo "<span class='errormsg'>ERROR: Pear Mail Module is not installed or not define at include path.</span>";
                echo "<HR/>";
                exit;
            }
        }
        else
        {
            echo "<span class='errormsg'>ERROR: Pear is not installed or not define at include path.</span>";
            echo "<HR/>";
            exit;
        }

        $errMsg = "";
        $notiMsg = "";

        if (isset($_REQUEST['mailer']))
        {
            $to = $_REQUEST['toEmail'];
            $subject = $_REQUEST['subject'];
            $message = $_REQUEST['emailContent'];
            $from = $_REQUEST['fromEmail'];

            if ($_REQUEST['mailer'][0] == "mail")
            {
                $mailer = Mail::factory('mail');
            }
            else if ($_REQUEST['mailer'][0] == "sendmail")
            {
                $mailer = Mail::factory('sendmail');
            }
            else if ($_REQUEST['mailer'][0] == "smtp")
            {
                $host = $_REQUEST['smtpserver'];
                $port = $_REQUEST['smtpport'];
                $auth = $_REQUEST['smtpAuth'] == "on" ? TRUE : FALSE;

                if ($auth)
                {
                    $username = $_REQUEST['emailUsername'];
                    $password = $_REQUEST['emailPassword'];
                }
                else
                {
                    $username = "";
                    $password = "";
                }

                $mailer = Mail::factory('smtp', array('host' => $host,
                        'port' => $port,
                        'auth' => $auth,
                        'username' => $username,
                        'password' => $password,
                        'debug' => true));
            }
            else
            {
                $errMsg = "No Mailer is choosen";
            }

            if (!strlen($errMsg))
            {
                $headers = array('From' => $from,
                    'To' => $to,
                    'Subject' => $subject);

                $mail = $mailer->send($to, $headers, $message);

                if (PEAR::isError($mail))
                {
                    $errMsg = $mail->getMessage();
                }
                else
                {
                    $notiMsg = "Email successfully sent!";
                }
            }

            if (strlen($errMsg))
            {
                echo "<BR/><span class='errormsg'>$errMsg</span>";
            }
            else if (strlen($notiMsg))
            {
                echo "<BR/><span class='notimsg'>$notiMsg</span>";
            }
            echo "<HR/>";
        }
        ?>
        <form method="post" action="" id="mailForm" onsubmit="return validateForm();">
            <table border="1" cellpadding="2" style="float: left">
                <tr>
                    <th colspan="2">
                        <input name="mailer[]" type="radio" value="mail" CHECKED onclick="document.getElementById('mailserver').style.display='none'"/>Mail()  
                        <input name="mailer[]" type="radio" value="sendmail" onclick="document.getElementById('mailserver').style.display='none'"/>Direct Sendmail  
                        <input id="mailerSMTP" name="mailer[]" type="radio" value="smtp" onclick="document.getElementById('mailserver').style.display=''"/>SMTP
                    </th>
                </tr>
                <tr>
                    <th><span style="color:red">*</span>From:</th>
                    <td><input id="fromEmail" name="fromEmail" size="30"/><div class="errormsg" id="fromEmailError"></div></td>
                </tr>
                <tr>
                    <th><span style="color:red">*</span>To:</th>
                    <td><input id="toEmail" name="toEmail" size="30"/><div class="errormsg" id="toEmailError"></div></td>
                </tr>
                <tr>
                    <th><span style="color:red">*</span>Subject:</th>
                    <td><input id="subject" name="subject" size="30"/><div class="errormsg" id="subjectError"></div></td>
                </tr>
                <tr>
                    <td colspan="2"><textarea id="emailContent" name="emailContent" cols="50" rows="8">This is a message</textarea></td>
                </tr>
            </table>

            <table id="mailserver" border="1" cellpadding="2" style="float: left; display:none">
                <tr>
                    <th colspan="2">Email Server Configuration</th>
                </tr>
                <tr>
                    <th><span style="color:red">*</span>SMTP Host:</th>
                    <td><input id="smtpserver" name="smtpserver" size="30" value="ssl://smtp.gmail.com"/><div class="errormsg" id="smtpserverError"></div></td>
                </tr>
                <tr>
                    <th><span style="color:red">*</span>SMTP Port:</th>
                    <td><input id="smtpport" name="smtpport" size="30" value="465"/><div class="errormsg" id="smtpportError"></div></td>
                </tr>
                <tr>
                    <th>Authentication:</th>
                    <td><input id="smtpAuth" name="smtpAuth" type="checkbox" CHECKED onchange="authChange()"/>Authentication Required</td>
                </tr>
                <tr>
                    <th><span id="emailUserRequired" style="color:red">*</span>Username:</th>
                    <td><input id="emailUsername" name="emailUsername" size="30"/><div class="errormsg" id="emailUsernameError"></div></td>
                </tr>
                <tr>
                    <th><span id="emailPasswordRequired" style="color:red">*</span>Password:</th>
                    <td><input id="emailPassword" type="password" name="emailPassword" size="30"/><div class="errormsg" id="emailPasswordError"></div></td>
                </tr>
            </table>
            <div style="height:5px; width: 100%; clear:both"></div>
            <input type="submit" value="Send Email">
        </form>
    </BODY>
</HTML>

Enhancement of jquery datetime plugin

2011-03-31T19:28:00.000-07:00

The problem
Lately integrate jquery datetime v1.0.5 plugin (http://plugins.jquery.com/project/datetime) into my web app to let user choose both date and time. When using it, found a problem if below conditions is applied.

Min date and Max date is set.
Default date and time is the middle of min and max date and the default date is following month of min date.
e.g. Min date is 28/04/2011, Max date is 30/06/2011 and default date is 30/04/2011 16:00.

The problem are

The calender shown May calender as expected but the previous button is disable and user cannot back to April which the Min date is set.
User can forward to additional two months after the Max date month, which mean this case the next button only disable when user access until month of August. However, user still cannot choose the date after the Max date.

The catch
After study the code found out the issue. (Following line number is refer to the src edition of javascript). Code between line 121 - 124 is in charge to enable and disabled the next and previous button. Originally, condition used is comparing the unix time get from date object ((min > date.getTime()) or ((min < date.getTime()). But somehow I found out that the date object day is modified at line 118 and this cause the month of date is changed in certain condition.

The solution
In order to solve the problem below is the code to replace the original code from line 121-124.
        html += ($.inArray(className, [ 'last', 'middle' ]) > -1) ? '' : '<a title="Prev" class="ui-datetime-prev ui-corner-all'+
          ((month <= this.minDate.getMonth()) ? ' ui-state-disabled' : '')+'"><span class="ui-icon ui-icon-circle-triangle-w">Prev</span></a>';

        html += ($.inArray(className, [ 'first', 'middle' ]) > -1) ? '' : '<a title="Next" class="ui-datetime-next ui-corner-all'+
        ((this.maxDate.getMonth() <= month) ? ' ui-state-disabled' : '')+'"><span class="ui-icon ui-icon-circle-triangle-e">Next</span></a>';

What I change is the rule of comparing (month <= this.minDate.getMonth() and (this.maxDate.getMonth() <= month). [month] is a variable created at line 114, it's out of for loop and it never change after initialization. Since calender navigation is month by month, I use the [month] to compare again the Min date and Max date month.

Excel column label calculation (increment)

2011-01-19T01:04:00.000-08:00

Sharing out the code that calculate the excel column label by increment. Suitable for any version of excel.

<?php
/**
* Calculate the column label base on incremental value
* @param string $txtCurrID Column label for start position
* @param int $intIncrement Number of columns that need to be forwarded
* @return string
*/
function increaseColumnID($txtCurrID, $intIncrement)
{
    $firstID="";
    $secondID="";
    $intCalVal="";

    /* Make sure the label is in upper case */
    $txtCurrID = strtoupper($txtCurrID);

    /* Split the label, since the max label is two character,
     * so take first and second character */
    if(2 == strlen($txtCurrID)) {
        $firstID = $txtCurrID[0];
        $secondID = $txtCurrID[1];
    } else if(1 == strlen($txtCurrID)) {
        $secondID = $txtCurrID;
    }

    /* If the increment more than 26, increase the first id by one
     * , reduct the increment 26 each loop until it smaller or
     * equal to 26 */
    while ($intIncrement > 26)
    {
        $intIncrement -= 26;
        if ($firstID == "") {
            $firstID = "A";
        } else {
            $firstID = chr(ord($firstID) + 1);
        }
    }

    /* If increment apply to current second label more than character 'Z'
     * (90), then we increment the first label again */
    if ((ord($secondID)+$intIncrement) > 90)
    {
        if ($firstID == "") {
            $firstID = "A";
        } else {
            $firstID = chr(ord($firstID) + 1);
        }

        $intIncrement = (ord($secondID)+$intIncrement) - 90;

        /* Need to minus one because we start from 'A' (65) */
        $secondID = chr(65 + $intIncrement -1);
    }
    else
    {
        $secondID = chr(ord($secondID)+$intIncrement);
    }

    /* return the calculated label in string format */
    return $firstID.$secondID;
}

echo "A:25 = ".increaseColumnID("A", 25)."<BR><BR>";
echo "A:26 = ".increaseColumnID("A", 26)."<BR><BR>";
echo "A:50 = ".increaseColumnID("A", 50)."<BR><BR>";
echo "aa:1 = ".increaseColumnID("aa", 1)."<BR><BR>";
echo "aa:26 = ".increaseColumnID("aa", 26)."<BR><BR>";
echo "aa:52 = ".increaseColumnID("aa", 52)."<BR><BR>";
echo "b:52 = ".increaseColumnID("b", 52)."<BR><BR>";
echo "A:100 = ".increaseColumnID("A", 100)."<BR><BR>";
?>

IE8 : jquery : ajaxfileupload : Syntax Error: Unterminated string constant

2011-01-16T18:56:00.000-08:00

The problem
Write a web app to upload a file, read the content then return the content in HTML table using JSON format then display the result dynamically at current HTML page. Below is the JSON return by a PHP script.

{filename: 'input.dat',total_recipient: '1',totalcolumn: '3',samples: '<table width="400px"><thead><tr><th>Column 1</th><th>Column 2</th><th>Column 3</th></tr></thead><tbody><tr><td>name</td><td>phone no</td><td>address</td></tr></tbody></table>',columntag: '{Col_1},{Col_2},{Col_3},'}

As usual it work perfectly on FF 3.5.3, but when come to IE8 I got the error message "Syntax Error: Unterminated string constant".

The catch
From the JSON alert on IE8, a linefeed (\r) follow by newline (\n) is inserted on some HTML tag. JSON result has following content.

{filename: 'input.dat',total_recipient: '1',totalcolumn: '3',samples: '\r\n<table width="400px">\r\n<thead>\r\n<tr>\r\n<th>Column 1</th>\r\n<th>Column 2</th>\r\n<th>Column 3</th></tr></thead>\r\n<tbody>\r\n<tr>\r\n<td>name</td>\r\n<td>phone no</td>\r\n<td>address</td></tr></tbody></table>',columntag: '{Col_1},{Col_2},{Col_3},'}

The solution
The quick hack is to remove the \r\n before it pass to browser to process. Edit the ajaxfileupload javascript file. At uploadHttpData function, look for the data type is JSON. Add following line before it run the eval() function.

data = data.replace(new RegExp( "[\\n|\\r]", "g" ), "");

Environment

Broswer : Internet Explorer 8.07600.16385
OS: Window 7
HTML Doc Type: DTD HTML 4.01
JS Lib: jquery 1.4.4
Jquery Plug-in: ajaxfileupload v1.0

IE8 : Object doesn't support this property or method

2011-01-15T07:24:00.000-08:00

The problem
Try to load following html to IE8 then insert some text to the input box and click the button. It should just alert the text you had key in but it give a javascript error "Object doesn't support this property or method". Below code work perferly on FF 3.5.3.

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<HTML><HEAD><TITLE>ID Test</TITLE>
<script type="text/javascript">
function testnow()
{
inputvalue = document.getElementById('inputvalue').value;
alert ("input value is ["+inputvalue+"]");
}
</script></HEAD>
<BODY>
<H3>Input Text</H3>
<input id="inputvalue" type="tet"></input>
<BR/>
<button onclick="testnow()">click me</button>
</BODY></HTML>

The catch
The cause of this js error is the HTML ID of the input (which is "inputvalue") is same as the js variable name used in testnow() function. IE8 seem can access the HTML element just use the ID directly. Try to replace testnow() function codes with this code alert (inputvalue.value); . It work in IE8! of course, will not work in FF3.5.3.

The solution

While declare a js variable, use the var keyword (e.g. var inputvalue="").
Do not use the same name at both HTML ID and javascript variable name.
Best practice, give better name for you variable like txtInputValue.

Environment

Broswer : Internet Explorer 8.07600.16385
OS: Window 7
HTML Doc Type: DTD HTML 4.01

Machine Image Tool - A GUI Disk Dump Tool

2010-05-08T08:28:00.000-07:00

While involving in cloud computing project, migrate virtual machine image is a common activity in order to use current virtual machine image in EUCALYPTUS environment.

However, for non technical people to

mount a loop file,
list the partition in the mounted loop file and
using disk dump (dd) to dump the partition to a file

is really not a straight forward job. To ease the user, I had build a java based GUI tool to solved the problem.

Following is the main features for Machine Image Tool (mitool)

Export partition to new loop file
Support Partition - primary
Support loop file format - RAW

It able to read a machine image in RAW format (qcow and VMDK not yet support) then show user all the partitions that contain in the machine image. User can select a partition and export to a file. The exported file then can use as the disk image in EUCALYPTUS cloud computing platform.

To have a try on this tool, please visit http://sourceforge.net/projects/mitool/.

-

COMCRAZY Development Center

The Journey of Anet A8 Part 2 - Upgrades & Mods

General Reading

Slicing Software

A8 Profile

Start G-code

End G-Code

PLA 1.75mm Filament Profile

Hardware Upgrades & Modes

1. Glass bed

Glass bed is a very useful upgrade, easy to clean, easy to stick and is cheap. Refer to my previous post for detail (The Journey of Anet A8 Part 1 - Setup & Stock Printing) 2. Auto Bed Leveling Sensor - 3D Touch

Installation

Firmware Upgrade

Calibrating Z-Offset With An Auto Bed Levelling Probe

3. Fan Duct

4. Extruder Button

5. Mosfet

6. Power Supply

7. T corner & Anti Z Wobble

9. Filament Guide

9. Spool Holder

10. Darth Vader Pop Figure

Some of my print

The Journey of Anet A8 Part 1 - Setup & Stock Printing

Un-boxing and Verify Received Goods

Setting Up the 3D Printer

Motors Position

Y Axis Belt

Alignment of T Lead Screw, Elastic Coupling and Z Motor

Power Supply

Calibration

Warped Heat bed

Calibrating Z Axis

3D Printer Profile

Printing

Adhesive, Adhesive & Adhesive - Why not sticking

Sample Prints

Guide & Upgrades

Summary

mBlock 3 Arduino Extension for 2-Wheel Robot Car

Workspace Environment Monitor - enVMon

Susurri - The Secret Message Service

Tropo Script

Server Side Script

base.php - Establish DB connection

getsession.php - Create a record in database and return id

searchrecord.php - Search record in database

updaterecord.php - Update record in database

schema.sql - Database schema

Tool for encode, decode and formatter for common use data

Password-less SSH Authentication Validation

Project Euler and Me

Problem 15

FORM validation with jquery.ajax

Document.getElementById return null

Useful Coding Tools and JavaScript Libraries For Web Developers - Smashing Magazine

Lessons From A Review Of JavaScript Code - Smashing Coding

Supporting Your Product: How To Provide Technical Support - Smashing Magazine

Free Download: Cheat Sheet For Designing Web Forms - Smashing UX Design

Panes Freezer - The jquery plugin

About

Demo

Supported browser

Links

MySQL Schema and Index Optimization Example

Javascript Multi-Dimension Array to JSON Converter

Associate Array

Normal Array

Not Array

Masza

Path Finding in PHP

Symfony Admin Generator Framework Skeleton

PHP Pear Mail Test Kit

Enhancement of jquery datetime plugin

Excel column label calculation (increment)

IE8 : jquery : ajaxfileupload : Syntax Error: Unterminated string constant

IE8 : Object doesn't support this property or method

Machine Image Tool - A GUI Disk Dump Tool

Glass bed is a very useful upgrade, easy to clean, easy to stick and is cheap. Refer to my previous post for detail (The Journey of Anet A8 Part 1 - Setup & Stock Printing)

2. Auto Bed Leveling Sensor - 3D Touch