We are running a survey to help us improve the experience for all of our members. If you see the survey appear, please take the time to tell us about your experience if you can.
Hi, i am trying to send AT commands to a k300 sony erricsson cell phone and then reading the response. Now i have done the sending part which is to send commands to the cell phone and is working perfectly but i want to see the response, i.e "OK", to be saved in a variable or something. I tried the uart method and serial transfer direct method with own functions method and in both i can transmit the data but never receive the "OK" Can anybody please help me.
" i have done the sending part which is to send commands to the cell phone and is working perfectly"
How do you know that?
"i can transmit the data but never receive the 'OK'"
How do you know that the K300 actually sends the OK?
Are you certain that you are using all the correct signal levels on all the required lines?
" i have done the sending part which is to send commands to the cell phone and is working perfectly
How do you know that?"
I know this because i sent AT+CKPD="1" which will press the cell phone button 1 which it did. So that tells me that the transmission works.
"i can transmit the data but never receive the 'OK'
How do you know that the K300 actually sends the OK?"
Because I had first tested the commands on hyperterminal and saw which commands gave what response.
"Are you certain that you are using all the correct signal levels on all the required lines?"
I think i am if i wasnt then the AT+CKPD="1" wouldnt of executed.
That's good. But you need to remember that nobody here knows anything about you or your project other than what you explicitly state in your post - hence the need to confirm these things.
"that tells me that the transmission works"
yes, that seems a good conclusion.
"I had first tested the commands on hyperterminal and saw which commands gave what response."
Good. But are you certain that your microcontroller connections is fully identical to your hyperterminal connection? In particular, do you have all the modem control lines connected and driven identically?
It is also possible that your microcontroller signal levels and/or timing are not quite right - close enough for the the modem to recognise the MCU's commands, but not (quite) close enough for the MCU to recognise the modem's responses...
If you connect your MCU to hyperterminal, do you see it sending the correct commands, and does it recognise responses typed into hyperterminal?
Have you checked with a scope if the module sends out an OK, or if the OK gets stuck because a handshake signal doesn't give the phone a go-ahead to send?
Look at the logic levels (or existence of pulses) on all signals when connected to the PC. Compare with the setup where you use your microcontroller.