While doing a project on GSM based energy meter billing system, Students came up with a requirement that the system should be able to detect if the SIM card has been inserted in GSM modem or not.

I was looking for a RF transceiver with good RF range for using in my project. But, when i looked at the specifications of the wireless devices, i did not find the RF range or distance mentioned in the details. This article is to give an idea on quickly calculating the range of your Wireless device using Transmit power and Receiver sensitivity. 

Looking for purchasing a RFID reader/writer for using in your project? Here is a compiled list of cheap low cost LF and HF RFID readers for online purchase in India. The features of the modules along with the online pricing is also given, 

Don't get confused between JOB and studies, " Studies is to learn and job is to earn ". Once you fall behind money you may not be truly interested in learning. Its true that you can gain practical experience in job, but it depends on the type of company you are joining.

SIM300 GSM modem operates at voltages from 3.6V to 4.5V. Most of the microcontrollers we use operate on +5V power supply and hence the IO signals also swing from 0 to 5V. This article discusses about connecting a 5V microcontroller UART lines to SIM300 GSM modem UART lines.

I have been hearing the name Arduino since some time, but never took the time to know what it is. Most of the time it popped up in front of me was in the form of an advertisement of a blue colored development kit. I thought it was just a hardware development kit from ATMEL.

This article describes the use of audio recorder/playback IC's APR9600/APR33A3 for playing recorded sound during a call. The call is made using a SIM300/SIM900 GSM modem. The audio interface for SIM300 and SIM900 are same. So, The below description should work with SIM300 and SIM900 modem as well.

Adding audio playback to a microcontroller circuit can be accomplished using either of two options, 

Option #1 is a low cost, low audio quality option

Option #2 is available only in high end controllers and could not be economical.

If you are looking at options for using an cheap/low cost, long range RF module for purchase in India, then here is one RF transciever with incredible 4000ft/1.2km/1200m line of sight range. The module operates on +3.3V DC power supply and provides a robust RF link between the transmitter and the receiver.

If you are an B.E Electronics and communication(E&C) engineer, here are a few career options you can look at after you complete your engineering. This article is just to give an idea for students who are studying or have just passed out of the college and looking for jobs or to start their career.