Hello,
I have designed an aoutomatic irrigation system in which the pump gets turned on or off based on the moisture content of the soil.
Now, i also want to control the pump through sms or call. I cant use any GSM sheild ans they are not available here nor can i order from abroad...GSM modems are available though....i need detailed help about the interfacing and codes....
Thank You!
Have you datasheets of the available GSM -modems?
To they talk TTL-level rs232?
Another option is to connect the backlight signal from a phone to an Arduino (analog?) in pin - GND connected too of course- so that when it receives an SMS some action will start.
Drawbacks:
= You can only define one action but that might be enough...
= Everyone can call the number..
I am yet to buy the GSM modem; it is a USB GPRS modem that is used to connect to internet using sim.
Could u kindly elaborate on the backlight signal?
Can i use the motherboard of a phone instead of a GPRS modem which has a built in GPRS modem? If so then how?
Thanks.
Another option is to connect the backlight signal from a phone to an Arduino (analog?) in pin - GND connected too of course- so that when it receives an SMS some action will start.
There are relay kits avaliable for doing this using a photo diode. If you watch your cell phone, the display will probably randomly light it self up to preclude the phone from being used for ugly purposes.
Could someone please tell me how to do it with a GSM modem...
Connect the GSM modem to the Serial port of the Arduino. Depending on the GSM modem you can poll it if there are messages availabale, of some others might make a line HIGH to indicate something is arriving.
How it is done exactly is written in the manual / datasheet. Modems tend to differ slightly... 
Google for "AT commands GSM Arduino" to see examples how it could be done,
The GSM modem that are available are of the USB type; so how can it be connected? Thanks
You can't connect USB devise to arduino w/o special shield.
But you can make connection to GSM phone , search Atmel's application note AVR323.
Thanks a lot! The Application note seems to be really helpful. I will go through it and will definitely ask for help if i need any...
It says that i can use any phone except Nokia phones that uses F or M-bus. Ho do i check that?
I cant use any GSM sheild ans they are not available here nor can i order from abroad...
Have a look at these. http://www.libelium.com/squidbee/index.php?title=New_GPRS_module_for_Arduino_(Hilo_-_Sagem)
There is are a lot of posts on Arduino and other forums about using this unit, from sending texts to networking.
Check with Google.
You can buy them at http://www.cooking-hacks.com/index.php/arduino-gprs-module.html (and probably elsewhere)
Thanks a lot...but i can't buy any sheild...
Hello, i have the phone shown in the link available: http://www.cpkb.org/wiki/Nokia_1680_classic_pinout
now i can connect the rx tx pins of the arduino Mega2560 board to the corresponding rx, tx of the phone...what to do after that if u want to turn on a motor by a phone call. Thanks!
Must read this stuff.....
it might be useful...