GSM controller...

The real nasty part starts here!!

In order to wirelessly control the generator I need the microcontroller to be able to recognize the massage (SMS) received from the authentic user.

Then in order to warn the user, I need the microcontroller to be able to send warning/failure massage to the user autonomously.

STEP 1

I needed a mobile which supports "AT-Commands" and which is compatible with a serial cable. After a lot of search, I finally got "Samsung C-130" along with a serial cable.

It cost me 800Rs. for the cell phone and 120Rs. for the cable.. ;)

STEP 2

Now I needed to make sure of the mobile operates properly with AT-Commands.
So I hooked up the mobile with my PC via serial port and sent commands through Hyperterminal at a BAUD rate of 4800bps and without any flow control.

BINGO... It worked out perfect at the very first try !!

continued in next post...

Now the RTC...

I'm using "DS-1307" for RTC (Real Time Clock). I've used I2C (Inter Integrated Circuit) protocol (aka the TWI-Two Wire Interface) to hook up this IC.

It can not only manage time with accuracy up-to 1 second, but it also manages complete calender with day, date,weeks passed,months and years. And it also caters for the leap year:)


"Here" is a link to the data sheet.

Another thing worth mentioning that this IC can maintain time and complete calender for up-to "10 Years" with a single Li-Ion (3Volts) backup cell.