PIC16f877A Sending SMS (AT commands) to Siemens C55

i changed code to send sms, i send AT with hyperterminal then gets OK, after all in simulation program i send only AT+CMSS=1, sms sent but i want to see "AT" ,"OK" then "AT+CMSS=1" one by one in proteus simulation. how can i do that. thx.

galapacos

there are many ways to check the modem response you can put a virtual terminal in protues. monitor the rx and tx to have an overview of what is going on in your system..

i cant take any response from mobile side,but in C code, i changed that sending "AT" after delay send "ATCMSS", dont wait OK response and it works but i want to see mobile response it is necessary to sending SMS. how can i do that? pls help..

how do you test your program anyway??

I suggest you to do it in proteus first so that you can easily monitor the RX and TX.. it is something like this

hello i want to ask a question. I sent SMS with COMPIM simulation but at the breadboard it doesn't work can u help me where is wrong? i connect all equiptment like proteus simulation. when i check the RS232's RX and TX i see the voltage but i couldnt understand where the wrong is...:SS

@romel_emperado

im using rs232 data cable, and i connected like this:

http://images.elektroda.net/50_1174089914.gif

i think something is wrong about pin voltages. Could you write siemens c55 rs232 male, max232 and microcontroller's physical connection. it works in simulation but i must make it in PCB. pls help me friends.

try to interchange the rx and tx

@ galapacos
u only need tx,rx and ground pins
use max232 and connect it to serial port now short the out put of max232 that is going to mobile for a while disconnect mobile and send any byte u will recieve that in this way it is verified that max portion is ok then go to next portion then interface it to mobile and see what happen then swap tx and rx some times it wrong

what should be pin's voltage? i used RX,TX and GND normally but in simulation COMPIM'S other pins change when it sending SMS green - red - green (means sending data i think so i should use that pin's too) i cant make it real world. i did what you said and not working. :S

In proteus connections are same like you see in Image posted by Romel. But when it comes to hardware you always have to go with Rx, Tx and GND. I think the circuit here is fine check voltages on Pin2 and Pin6 of max232. you must see +ve voltage on Pin2 and -ve on Pin6.


If it still does not work then connect the cable (microcontroller side) to PC. and see if you can get it to work. if yes then probably there is something wrong with your controller or program.

i think it is about voltage differences between siemens c55 pins and pic :Si couldnt solve it :S