SWADEXI BLOG

Jitsi Command Library

2020-10-24T18:11:00.004-07:00

1. Running Jicofo

systemctl restart jicofo

2. bind-http jitsi

Check : curl http://localhost:5280/http-bind

3. Prosody

Restart: /etc/init.d/prosody start

status sudo prosodyctl status

stop prosodyctl stop

4. Uninstall Jitsi

sudo apt purge jigasi jitsi-meet jitsi-meet-web-config jitsi-meet-prosody jitsi-meet-turnserver jitsi-meet-web jicofo jitsi-videobridge2

5. Jitsi Nginx

server {
   listen 443;
    server_name vcon.hano.xyz;
    # set the root
    root /usr/share/jitsi-meet;
    index index.html;
    location ~ ^/([a-zA-Z0-9=\?]+)$ {
        rewrite ^/(.*)$ / break;
    }
    location / {
        ssi on;
    }

    location /http-bind {
        proxy_pass      http://localhost:5280/http-bind;
        proxy_set_header X-Forwarded-For $remote_addr;
        proxy_set_header Host $http_host;
    }

    location /external_api.js {
        alias /usr/share/jitsi-meet/libs/external_api.min.js;
    }

   location = /config.js {
    alias /etc/jitsi/meet/vcon.hano.xyz-config.js;
}
ssl on;

ssl_certificate /etc/letsencrypt/live/vcon.hano.xyz/cert.pem;
ssl_certificate_key /etc/letsencrypt/live/vcon.hano.xyz/privkey.pem;
}

Java Keystore Problem: Trustore with Subject CN is Not Ca Certificate

2020-06-27T22:06:00.002-07:00

Detailed Step by Step instructions I followed to achieve this

SSource : StackOverflow =>
Vipul

Download bouncycastle JAR from http://repo2.maven.org/maven2/org/bouncycastle/bcprov-ext-jdk15on/1.46/bcprov-ext-jdk15on-1.46.jar or take it from the "doc" folder.
Configure BouncyCastle for PC using one of the below methods.
- Adding the BC Provider Statically (Recommended)
  - Copy the bcprov-ext-jdk15on-1.46.jar to each
    - D:\tools\jdk1.5.0_09\jre\lib\ext (JDK (bundled JRE)
    - D:\tools\jre1.5.0_09\lib\ext (JRE)
    - C:\ (location to be used in env variable)
  - Modify the java.security file under
    - D:\tools\jdk1.5.0_09\jre\lib\security
    - D:\tools\jre1.5.0_09\lib\security
    - and add the following entry
      - security.provider.7=org.bouncycastle.jce.provider.BouncyCastleProvider
  - Add the following environment variable in "User Variables" section
    - CLASSPATH=%CLASSPATH%;c:\bcprov-ext-jdk15on-1.46.jar
- Add bcprov-ext-jdk15on-1.46.jar to CLASSPATH of your project and Add the following line in your code
  - Security.addProvider(new BouncyCastleProvider());
Generate the Keystore using Bouncy Castle
- Run the following command
  - keytool -genkey -alias myproject -keystore C:/myproject.keystore -storepass myproject -storetype BKS -provider org.bouncycastle.jce.provider.BouncyCastleProvider
- This generates the file C:\myproject.keystore
- Run the following command to check if it is properly generated or not
  - keytool -list -keystore C:\myproject.keystore -storetype BKS
Configure BouncyCastle for TOMCAT
- Open D:\tools\apache-tomcat-6.0.35\conf\server.xml and add the following entry
  - <Connector port="8443" keystorePass="myproject" alias="myproject" keystore="c:/myproject.keystore" keystoreType="BKS" SSLEnabled="true" clientAuth="false" protocol="HTTP/1.1" scheme="https" secure="true" sslProtocol="TLS" sslImplementationName="org.bouncycastle.jce.provider.BouncyCastleProvider"/>
- Restart the server after these changes.
Configure BouncyCastle for Android Client
- No need to configure since Android supports Bouncy Castle Version 1.46 internally in the provided "android.jar".
- Just implement your version of HTTP Client (MyHttpClient.java can be found below) and set the following in code
  - SSLSocketFactory.setHostnameVerifier(SSLSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER);
- If you don't do this, it gives an exception as below
  - javax.net.ssl.SSLException: hostname in certificate didn't match: <192.168.104.66> !=
- In production mode, change the above code to
  - SSLSocketFactory.setHostnameVerifier(SSLSocketFactory.STRICT_HOSTNAME_VERIFIER);

Instalation and Configuration Minio Storage Server in Linux Ubuntu 18.04

2020-03-07T13:31:00.001-08:00

1. Download minio

wget https://dl.min.io/server/minio/release/linux-amd64/minio

2. Install Minio

 chmod +x minio

./minio server /data

3. Change Credential

export MINIO_ACCESS_KEY=YQWERTYU12RHJW2YJASD
export MINIO_SECRET_KEY= xH+Qwerty+ASDF+HDd7DRNOFvl7sL8ASDFjwZXCg

4. Run server

./minio server /data

5. Monit Configuration

check process minio
        matching minio
        start program = "/bin/bash -c '/root/minio.py start'"
        stop program = "/bin/bash -c '/root/minio.py stop'"
        if cpu usage > 95% for 10 cycles then restart

6. Python minio.py

#!/usr/bin/python2
import sys
import os
action = sys.argv[1]
if action == 'start':
os.system("export MINIO_ACCESS_KEY=YQWERTYU12RHJW2YJASD \n export MINIO_SECRET_KEY=xH+Qwerty+ASDF+HDd7DRNOFvl7sL8ASDFjwZXCg \n /root/minio server /data")
if action == 'stop':
os.system("kill -9 $(pgrep minio)")

7. Change permision of minio.py file

chmod +x minio.py

8. Restart Monit

systemctl restart monit

9. Status Monit Check

systemctl status monit

Install Java 13 Oracle

2020-03-07T02:47:00.000-08:00

sudo apt-get update

sudo apt-get install oracle-java13-installer

Check the result via command: java --version

How to using ARM Bluepill STM32F103C8 on Arduino Ide

2019-09-11T01:30:00.002-07:00

1. Download STM32 Driver from this site https://github.com/rogerclarkmelbourne/Arduino_STM32
2. Extract and Install Arduino_STM32-master\drivers\win\install_drivers.bat or install_STM_COM_drivers.bat
3. This driver is must be installed correctly. if you are still found your driver as Usb serial device, it will show the errror " Couldn't find the DFU device: [1EAF:0003] "
4. the following Configurations is needed.

How to Copy Colored Script Code in Arduino IDE to Word or other formated text

2019-08-22T19:24:00.004-07:00

if you want to write arduino tutorial on a book, and you want to coloring your script like arduino script. there are two ways to do this

1. using snipping tools to screenshot your code
2. using the following ways

Visit https://codebeautify.org/htmlviewer/
on arduino ide, ctrl+a (select all) your script and Right Click, Copy as html
Paste on HTML input
and copy your script on Result : HTML Output to your microsoft word

Multiple SSL sub Domain LetsEncrypt

2019-05-11T19:23:00.001-07:00

If you want to install ssl on all subdomain you can use the following

sudo certbot-auto certonly -d *.example.com --server https://acme-v02.api.letsencrypt.org/directory --preferred-challenges dns --manual

Android Keystore From Letsencrypt

2019-04-23T22:52:00.002-07:00

Here

Download: https://bouncycastle.org/download/bcprov-jdk15on-161.jar
place the file above in the same folder of certtificate

export CLASSPATH=bcprov-jdk15on-161.jar
CERTSTORE=whisper.store
if [ -a $CERTSTORE ]; then
    rm $CERTSTORE || exit 1
fi
keytool \
      -import \
      -v \
      -trustcacerts \
      -alias 0 \
      -file <(openssl x509 -in cert.pem) \
      -keystore $CERTSTORE \
      -storetype BKS \
      -provider org.bouncycastle.jce.provider.BouncyCastleProvider \
      -providerpath /usr/share/java/bcprov.jar \
      -storepass whisper

How To Install Let’s Encrypt on Ubuntu and Export Jetty Keystore

2019-04-23T22:47:00.000-07:00

Step 1 Install Letencryptt:

sudo apt-get install letsencrypt

step 2. download Certbot

sudo wget https://dl.eff.org/certbot-auto -O /usr/sbin/certbot-auto sudo chmod a+x /usr/sbin/certbot-auto

step 3. SSL certificate

sudo certbot-auto certonly --standalone -d example.com  -d www.example.com

# the "auth" aka "certonly" subcommand

# convert certificate chain + private key to the PKCS#12 file format

openssl pkcs12 -export -out keystore.pkcs12 -in fullchain.pem -inkey privkey.pem

# convert PKCS#12 file into Java keystore format

keytool -importkeystore -srckeystore keystore.pkcs12 -srcstoretype PKCS12 -destkeystore keystore.jks

# don't need the PKCS#12 file anymore

rm keystore.pkcs12

# Now use "keystore.jks" as keystore in jetty with the keystore password you specfied when you ran

# the "keytool" command

# input: fullchain.pem and privkey.pem as generated by the "letsencrypt-auto" script when run with

Maven error :Perhaps you are running on a JRE rather than a JDK?

2019-04-20T02:38:00.002-07:00

I've been facing the same issue with java 8 (ubuntu 16.04), trying to compile using mvn command line.
I verified my $JAVA_HOME, java -version and mvn -version. Everything seems to be okay pointing to /usr/lib/jvm/java-8-openjdk-amd64.
It appears that java-8-openjdk-amd64 is not completly installed by default and only contains the JRE (despite its name "jdk").
Re-installing the JDK did the trick.

sudo apt-get install openjdk-8-jdk

Edit XY Graph Window Simulink Plot

2018-12-23T15:27:00.002-08:00

if you want to edit the simulink xy graph, you can follow th intructions below:


xy graph simulink plot

1. Run your simulink program, then the XY dialog will show up
2. Type the following command :

 set(0,'ShowHiddenHandles','on')

 set(gcf,'menubar','figure')

These commands will enable the toolbar in X-Y graph figure window. You can add axes names from Insert >> X Label and Insert >> Y Label. 

[SOLVED] Xamarin Studio Android SDK Not Found ... Searched Windows Registry

2018-08-26T04:17:00.000-07:00

If you use Xamarin Studio For the first time, i suggest you to create a very simple apps that is two click. then test your project. if you face the following error :

SetUp : System.Exception : Android SDK not found. Please install it and if it is still not located, please set the ANDROID_HOME environment variable to point to the directory.
Searched locations:
Windows Registry
(No path) - Not set. [ Source: ANDROID_HOME ]

or

SetUp : System.Exception : Java Development Kit (JDK) not found. Please make sure that it is installed and if it's still not located, please set the JAVA_HOME environment variable to point to the directory.

Searched locations:Windows Registry
[ Source: JAVA_HOME ]

then use the following solutions (see the picture),
1. Go to this pc and Right -click then click properties

[SOLUTION] Select Database The N numbers Last or First Rows in Codeigniter

2018-08-24T16:29:00.004-07:00

If you want to select the N last rows or N first rows, in codeigniter you can use the following script

$n = 100;

$this->db->limit(n);

$this->db->order_by("id", "desc"); // N last rows 
$query = $this->db->get('my_table');
$myRow = $query->row();

$n = 100;

$this->db->limit(n);

$this->db->order_by("id", "asc"); // N first rows 
$query = $this->db->get('my_table');
$myRow = $query->row();

[ Research ] Autonomous Land Vehicle In Progress

2018-08-17T17:15:00.001-07:00

We are currently research the Automomous Land Vehicle in Institut Teknologi Sumatera, Indonesia. The Autonomous system is using GPS to obtain location of vehicle and using PID control in steering system and position tracking system.

Vehicle

The progress of research is still 40% complete. we are still researching in control and web based control station.

[SOLVED] HMC5883L not working ( i2c adress:0x0D instead of 0x1E )

2018-08-14T00:03:00.002-07:00

do you buy HMC5883L but the device not working?
if yes, you should check the i2c adress by using i2c scanner. --link--

if in i2c scanner you found device address is 0x0D then your trouble is wrong library, but if terminal say i2c not found, the problem is on hardware connection.

if address is 0x0D this is different with hmc5883L because this module is using qmc5883L ic. so the library is different with hmc5883L library.

To solve this issue, you can use the following library to work with your compass module.

Download Qmc5883L library

[SOLVED] How to move Application Folder to the Basepath (root) in Codeigniter

2018-06-13T22:33:00.004-07:00

Codeigniter Application folder is where our job begin, the default structure of codeigniter is

basepath/aplication
basepath/system

now you want to move your application content to the site, you can use the following way

in index.php :

on line 117 change value to empty then

$application_folder = '';

and in line 239 change from

if (is_dir($application_folder))

to

if ($application_folder=='')

Done.

How to Start Learn PLC (Programmable Logic Controller)

2018-06-12T00:30:00.002-07:00

PLC is a device that is used in most industries in the world to control of system in industry. For electrical engineering that focus on control system PLC is a device that has to be learned. Then how to start to learn PLC? if you have device, you can start by programming the device. but what if you didnt have the PLC? you can start by simulation.

PLC Fx Trainer

What is the best simulator that can be used? there are many PLC Simulators that can be used, and also there is Online PLC simulator. but i recommended to use Mitsubishi PLC Fx-Trainner, this software has great simulation tools and 3D simulation of industry devices. You can download PLC Fx Trainer by searching on google and start the learning

Solve Mathematical Problem Using Web App

2018-06-12T00:10:00.001-07:00

Have you ever found a math problem that is need to be solved quickly? sometime, we need to know how math problems is solved for example when you in college or in school, but in another case, you only need to know the answer quickly without knowing how it done. There is some tools which can help you to solve math quickly.

1. Matlab

Matlab is premium software that that have a great ability in Math problem, for example in Control system simulation, matrix , laplace, fourier, bode plot and etc. this application is available in Windows, Linux and Mac OS.

2. Wolfram Alpha - Link
This is the recommended for you who need quickly solution of math problem, because wolfram alpha is web based app that free to use. you can get the Math Solution such as :
a. Laplace
b. Integral
c. Elementary Math
d. Plotting Graph
e. Trigonometri
f. and so much more

How to Delete your gitHub Repositories

2018-06-06T22:26:00.001-07:00

If you have github account and trying to delete your gitHub repositories you can use the following way:

1. Login to your github Account
2. Go to your repositories that you want to deleted, for example

https://github.com/name/repoName/

3. Go to setting Menu

4. Scroll to the bottom of the page (go to danger zone) and Delete this repository

5. type your repository name to confirm the delete action

How to add Images in Readme.md gitHub

2018-06-06T22:15:00.003-07:00

I just already joined github and trying to share project on github. and in the github there is feature to explain our project by writing on readme.md, and maybe you would to place any picture on your tutorial. you can use the following script to do that

![alt text](http://url/to/img.png)

For example

![alt text](http://1.bp.blogspot.com//bottom.png)

Download Open Source Ground Control Station C#

2018-06-06T21:53:00.000-07:00

Long Time not writing on this blog, now i'm focus on quadrotor control simulation using Matlab for My Master Thesis Project. in other time, i will explain how to simulate quadrotor on matlab.

In this chance i wanna share my Undergraduate Final Project, that is DXGCS ground control station. My First Ground Control Station (GCS) is built from C# Microsoft Visual Studio 2010. You Can use it for free but i hope. dont remove the Copyright of My Name : Swadexi istiqphara . And I Hope there is the Development of my GCS.
The Feature and system requirement to Run this GCS is explained on this LINK

OK this is My C# GCS, Download from github

Github Link

[SOLVED] Codeigniter DB Error "The mysql extension is deprecated ..."

2018-06-06T20:45:00.001-07:00

Codeigniter is popular PHP framework that helps you in php programming, if you using Apache server with PHP 5.5 above, you will see the following error when you using database mysql :

mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead

To solve this issue you have to add a line of the following script

 error_reporting(error_reporting() & ~E_DEPRECATED);

to Codeigniter folder \system\database\drivers\mysql\mysql_driver.php

open mysql_driver.php and add the above script to line 134. So your edited mysql_driver.php become like this

[SOLVED] PHP Permutation of given words with all posibilities of combination

2018-06-05T21:34:00.001-07:00

If you want to create a permutation with all posibilities of words in PHP, you can use the following script

if(isset($_POST['submit'])){
    $data     = $_POST['data'];
    $arr = explode(' ',$data);
    permutasikan($arr);
}
function permutasikan($items, $perms = array()) {
    if (empty($items)) {
        echo join(' ', $perms) . "\n";
    } else {
        for ($i = count($items) - 1; $i >= 0; --$i) {
             $newitems = $items;
             $newperms = $perms;
             list($foo) = array_splice($newitems, $i, 1);
             array_unshift($newperms, $foo);
             permutasikan($newitems, $newperms);
         }
    }
}

[Solved ] Android Studio Stuck at Building 'xyz' Gradle Project Info

2017-10-14T11:36:00.000-07:00

I Just Installed Android Studio 2.2.3 on My Windows7 Notebook, when i tried to create new project, then the following dialog is showing in unkown estimated time.

To Solve this issue try the following method :

Close The Android Studio Application.if you can not do this, you should use task manager to force close the android studio
Goto C:\Users\username\.gradle folder
There is a folder there that show you which version of gradle Android Studio requires (e.g. gradle-2.10-bin)
Download this version from this link or Link2 and download the complete version ( gradle-all)
Goto C:\Users\username\.gradle\wrapper\dists\gradle-x.y-bin
There is a folder here that its name is like a GUID.
You should just copy the zip file that you've already downloaded from internet into this folder.
Execute Android Studio and create a new project.

Force to Completelly Uninstall Driver from driver store on Windows

2017-10-12T08:30:00.005-07:00

This is the solution of problem caused by USB blaster. when you tried to uninstall the old driver of usb blaster, you cannot install the new driver until completely remove the driver in driver store.

To Uninstall the Driver completely you can do the following tricks in command promt :

to list the Altera Driver use the following command

pnputil -e

then it will list the driver name

the type following command

pnputil.exe -f -d OemNumber.inf