Comments on: SMS remote control

By: palas

palas — Thu, 09 Dec 2010 04:18:54 +0000

palas_ruet_eee@yahoo.com
i need a circuit diagram on how this siemens mobile is connected to microcontroller.
will any-one help me.
if any one has a link or this connection diagram please mail me.palas_ruet_eee@yahoo.com

By: little sister

little sister — Fri, 30 Jul 2010 07:11:30 +0000

..that’s totally sweet. You always blow me away with this stuff. How are we even related??

You remember when Calvin imagined that he had a huge brain and his head was all crazy and misshaped? That’s still how I think of you. Well, no.. not.. having a deformed head but…

nevermind.

By: imsolidstate

imsolidstate — Tue, 20 Jul 2010 15:05:09 +0000

I looked into GSM modules, but I couldn't find any for cheap. The best deals are over at Sparkfun, but you're spending roughly $90 to get a module. The link you sent from mikroElektronika is just the breakout board for a module, you still have to buy the module. That's why I went with the cell phone, it's about twenty bucks. The PDU thing is a pain, so spending the money is probably worth it.

By: imsolidstate

imsolidstate — Tue, 20 Jul 2010 14:56:54 +0000

Thanks, I’ll fix that. The program never returns from the decode_sms() routine. Unfortunately, there’s a lot that could go wrong there. I suspect one of my offsets to break up the PDU string is incorrect. I need to debug the code (I added a bunch of diagnostic LEDs for that purpose) but haven’t had time due to other projects. Thanks for your help!

By: Jon S

Jon S — Tue, 20 Jul 2010 04:47:27 +0000

I would look into one of the GSM modules from Mikroelektronika. They connect thru serial link to your uC. http://www.mikroe.com/eng/categories/view/19/gsm-gprs-tools/

I’ve been eyeing some of their boards for GSM SMS capabilities. You just need to make sure that the specific module supports the SMS without being in PDU mode. The Telit GM862 supports SMS in Text mode. Although a downside is that it will probably cost more than the cellphone you bought.

By: Antoine

Antoine — Tue, 20 Jul 2010 03:15:50 +0000

Hey,

I quickly surveyed your program and found that when you are comparing strings such as in :
message[0x01]==’e’ &
message[0x02]==’l’ &
message[0x03]==’a’ &

you are using a single ampersand which is the bitwise AND operator. You want the AND logical operator which is &&. I think your comparisons will still work, but they are dependent on a true being represented by the same value while the C standard defines true as not 0. Doing it this way probably leads to a faster comparison, but its risky.

Otherwise, I cannot see what is wrong with it. It would help a lot if it was commented.

You probably tried sending commands to the AVR using a computer’s serial port or sniffing the contents or command from the cell-phone. Where does it stops working exactly?