Joko Sastriawan

Sending SMS via GPRS modem using Perl Device::SerialPort

2011-10-20T13:18:00.000+07:00

Sometimes ago, I posted a script to send SMS using Gammu. Now, I would like to deep dive on the underlying communication to GPRS modem using AT command to send SMS. The sequence of AT commands to use are: ATZ : Reset modem ATE0 : Disable echo (not necessary) AT+CMGF : Setting the SMS mode (Text or PDU) AT+CSCA : Query or set the SMS center number AT+CMGS: Send SMS To cut the story

3G/GPRS connection using pppd and chat for M2M communication

2011-10-13T10:58:00.000+07:00

In most cases, connecting to the Internet using 3G modem on normal desktop Linux is fairly easy because the networking support framework is quite mature. However, for small embedded system, having a full blown networking support framework is a luxury. And usually the desktop networking framework is developed for interactive human intervention whereas for some embedded cases the 3G network

Linux kernel modules configuration on Yocto Project Bernard

2011-04-19T18:02:00.000+07:00

For the last two weeks, I have been working on developing custom Linux OS image using Yocto Project system. One of the requirement is that the device should support V4L(1|2) and various USB webcam. However the default kernel configuration does not contain the required options. I have been trying to: - add defconfig file into recipes but it is always been ignored by Bitbake - add partial kernel

End of the year 2010 reflection

2010-12-28T17:04:00.000+07:00

A lot had happened this year, and so many important decisions were made. Leaving previous companies and accepting a new position at Intel Indonesia were the key decisions. Engineering tasks have always been my passion. Hands-on design and coding, tackling clients' problem, out of the box thinking on problem solving had always been my day to day tasks. For the last 8 months, I have moved on to

Using Zimbra LDAP as Spring-security backend and handling Linux/BSD MD5 encrypted password

2010-02-15T14:18:00.001+07:00

LDAP has been one of the most common way of managing user credentials for most company. Email and other services may use LDAP to authenticate users. I have been using with Spring Security for quite sometime however recently I have a very challenging task of integrating Zimbra LDAP as Spring Security backend. Zimbra LDAP does not allow user to connect and authenticate directly (no binding

Using javax.xml.soap to access OTRS SOAP service without WSDL

2010-01-25T15:51:00.001+07:00

For most of us who are frequently using WSDL to generate stub classes for accessing webservices, dealing with SOAP services without WSDL is painful. OTRS (Open source Ticket Request System) is one of them. One attempt by OpenNMS team has been quite successful on integrating OTRS by writing its own webservice as an OTRS plugin. However, this is not satisfactory in my opinion. We need a better way

Accessing WS-Security protected (UsernameToken) WebService using PHP5 Soap

2010-01-15T15:40:00.000+07:00

After battling for several hour trying to figure out on how to send WS-Security header using PHP5 Soap API, I finally managed to discover the work of the good people at University of Toronto . Using their example and the PHP code they posted on the website: soap-wsse.php and xmlseclibs.php, I have been able to test my CXF-powered webservice. I have a web service running at http://localhost:9090/

Mono WebClient Basic Authorization pre-authenticate problems

2010-01-11T14:41:00.000+07:00

For the last few week I have been trying to set Mono WebClient to send (.. yeah.. simple... just send the fricking..) Basic Authorization header. Apparently, somebody is just too smart to decide not sending the header on the first request for security reason (sending user credential). Well, the problem is that Acegi/Spring security does not necessarily send 401 header since authentication can be

Simplified SnmpUtility class based upon SNMP4J

2009-11-03T20:51:00.004+07:00

Due to popular request, I am posting my wrapper code or SnmpUtility based upon SNMP4J. I copy some part of this code somewhere that I could remember. So, I do apologise if I could not give the original author a proper credit. Updated: < and > were unable to display properly so the generic is not seen properly. I wish it is fixed now. Here is how to use it: SnmpUtility util = new SnmpUtility(

Workaround on installing Android SDK 2.0 behind proxy requiring authentication

2009-10-28T09:20:00.004+07:00

This morning I tried to install Android SDK 2.0 on my Ubuntu desktop. I downloaded the package with my browser without any problem. Extract it and then run tools/android to download the packages. Realising that my desktop requires a proxy which requires authentication to get to the Net, I went to the Settings panel of the Android SDK and AVD. There are only proxy host and port entries, no

Mass sending SMS using gnokii

2009-09-23T15:56:00.003+07:00

During certain period within a year, we might have to send text messages (festivity greeting) to several friends for example during religious holiday season. Well, writing one template and re-sending text messages through your mobile phone might be OK for 5 or 10 numbers. How about if you have to reply 25 to 50 text messages? Sore thumb :) Gnokii is very good at sending SMS via a GSM/3G/HSDPA

Opennms build failed due to xerces problem (affecting 1.6.x)

2009-07-09T10:54:00.003+07:00

For some of you who may have tried building opennms from scratch, you may find a problem where build failed due to xerces dependencies could not be found. Based on several post that I have read, it is due to the relocation of the files. Well, the simples work around to that is to install xerces-1.4.0.jar into your local maven repository. This is the syntax command to do that: mvn install:

JDBC class loading failed from JAX-WS annotated class

2009-06-25T15:54:00.006+07:00

Creating a JAX-WS based webservice either using JAX-WS RI or Apache CXF is simplified by using annotation, for example creating interface annotated with @WebService is a simple as the following: @WebService public interface AService { @WebMethod String getThingsFromJDBC(String key); } Then the interface is implemented as the following: @WebService public class AServiceImpl implements

Running RMIC via ant

2009-06-17T10:10:00.009+07:00

Netbeans, does not support RMI-based project quite well especially on generating stub files using RMIC. However, we can always tweak the build-impl.xml script to run RMIC. To generate stub files, RMIC must be executed after class compilation finished. Thus, the most appropriate place to run it is in -post-compile target. Here is a snippet on how to invoke RMIC in -post-compile target. I found

Intel HDA modem on Hardy Heron

2008-08-11T17:59:00.004+07:00

My laptop, a two years old Toshiba A100 Core Duo, has a built-in modem. It is based on Intel HDA modem. I have been struggling to use it under Ubuntu during its (the laptop) early day. So, I never touch it again, instead I have been using my Dopod 383Pro as HSDPA modem -- in emergency situation. Today, I have seen several articles pointing at slmodemd and how to use it. In the spirit of

Simple Netfilter internet connection sharing

2008-07-29T08:06:00.015+07:00

Imagine this, you are in a meeting with your work mates in a hotel which charges unreasonably high internet access fee. You are connected to the Internet via your HSDPA modem. Your mates need to check his mail and to do some administrative stuff on the groupware. You want to share your internet connection and you are using Linux with Iptables(netfilter) installed (whoo..hooo....). Now, how do you

A Simple SNMP4J usage

2008-07-28T12:35:00.007+07:00

For some network administrator, querying an SNMP agent is as simple as executing: snmpwalk -v2c -c public localhost system Similarly, Java application developer could do that as well using SNMP4J quite easily. Oh, BTW, don't complain about the length of the code because I don't know how to attach the code to this post..:( Here is the import code snippet org.jbs.snmputils.*