Code Igniter form_open changes URL

 If you are a new user to the php framework CodeIgniter, you may face a problem when submitting a form using helper form_open(). Let's discuss by the following example which is downloaded with the framework:


Step 1: After downloading and installing the framework, we have the following project structure.

|- system/
|- application/
|---- models/
|---- views/
|---- controllers/
|- public/
|---- images/
|---- js/
|---- css/
|---- index.php
|---- .htaccess

PHP hello world without a localhost

Usually when we develop a web page with dynamic content, we start using a local host. This is needed to easily develop and test your web page. However, sometimes you need to show the webpage to your colleagues or to a freelancer client. In that case, you need to deploy the web page on a real domain.  For example, let's consider the following basic PHP project, it only contains 1 html file, and 1 php action.

Unable to add network node in CANoe

Today I wasted 1 hour in a trivial error, but I found out that it was not answered in a forum entitled How to enable CAPL node. Simply, I was working with CAN hardware VN1630A, and I was trying to add a network node by right clicking the blue/red bus as shown below. Surprisingly, the menu option "Insert Network Node" is disabled.

Installing ETTUS RFNoC

RFNoC is a branch to the universal hardware driver UHD of ETTUS platform [1]. Its primary goal is to simplify the FPGA coding process [2][3]. For example, to add a new FFT module to the existing UHD code may take weeks. Thanks to RFNoC this will be reduced to few hours[3].
The first thing to get started with RFNoC is to install it (that makes sense!). I installed RFNoC an Ubuntu virtual machine. Although the installation steps are explained in the RFNoC wiki [4], I had many troubles installing it. Therefore, I decided to write this document with detailed installation steps until the gnu radio companion looks like this picture.

Matlab Model for Open BTS project

Goal

To provide high level model to modify the Verilog code of OpenBTS project. The OpenBTS provides a cheap alternative to standard BTS ‎. Hence, rural communities can enjoy cheap and basic telecommunication services using Global System for Mobile communications (GSM) [32]. 

High level block diagram of Open BTS Matlab model

Cloning the usrp3 GIT repository on windows

To be able to build custom FPGA image for the USRP3, the first step is to copy (clone) the source code from the ETTUS repository. There are several methods to use git on windows. In this mini article, the fpga source code for OpenBTS will be fetched from https://github.com/EttusResearch/fpga/tree/master.
 
Step 1:
Install GIT client  msysgit from https://msysgit.github.io/.  The downloaded file will have a name similar to "Git-1.9.4-preview20140929".

Modifying FPGA image of USRP

Motivation

I attended some sessions in the conference (COCORA 2014) in Nice, France. I had the chance to talk to the speakers in the panel that focused on Software Defined Radio (SDR). I was presenting the topic of improving the role of FPGA in OpenBTS project. OpenBTS is an open source GSM network based on the Universal Software Radio Peripheral (USRP). Unlike me, most of the speakers focused on applications of cognitive radio at high level. They adopted the idea that "for FPGA, what is done is done". Well, our team see a lot of opportunities in modifying the FPGA Code.