PIC16F877 - Siemens C55 - max232 - rs232 SMS Sending

• You successfully communicate to your mobile using PC...

• As you said you successfully send msg using hyperterminal.
  

i send sms with hyper terminal,

i send sms with my proteus electronic circuit SIMULATION (not with hyperterminal) on pc with setup my c code in MCU

ah nice you already send sms from proteus simulation.

Can u post the portion of your code that sends sms.?
What is the model of your uc board? Of f u have piture pls post.

firatly i save a pdu message to mobile phone's memory with hyper terminal then i send command AT+CMSS=1 it means send first SMS from mobile memory. i share my code at first page. three times i send AT dont wait any response from mobile then after delay AT+CMSS=1 and sms sending.

i connect rs232 from laptop to my max232 RX and TX and trying to send command to my phone?

right?

galapacos

That is right.
Your diagram is wrong though.
The "RS232" bubble is between the PC and MAX232 not MAX232 and phone.
RS232 uses + and - voltages which would damage your phone.

So we have + and - voltages from the PC to the MAX232 ,
the MAX232 converts them to 0 and 5 volt signals to send to the phone.

As I said earlier, the phone really wants 0 to 3 volt signals, but 0 to 5 should be okay.

As a test, connect MAX232 pins 9 and 10 to each other, not the phone.
What you type in Hyperterminal should be echoed back.

firstly i connect my laptop's rs232 to my PIC16f877 microcontroller and i saw my Commands three times "AT" then "AT+CMSS=1" i dont use mpbile phone and i understood that my microcontroller works.

secondly i connect my laptop's rs232 to MAX232 and my mobile phone and i opened hyperterminal program and send AT and AT+CMSS=1 to my laptop rs232 comport but it doesnt work. :S

i think to problem is about max232 doesnt configure the voltage levels to send datas to mobile. anyone have an idea about this, what can i do for this problem????

thx

you said 9 and 10 pins, are they which i connecting max232 to my mobile phone?

i connected my pc's rs232 TX -13, RX - 14

and 11 - 12 connected each other there is no phone right?

i used this schematic

We need to stick to one diagram, and take simple steps, or we will go round in circles.

On this board pins 9 and 10 connect to the phone.


If you connect them together instead of to the phone, anything sent to the interface should be sent back to the PC.
We need to see that that part works.
Use Hyperterminal to send,and see what comes back.

nothing comes back to my screen. :S