First at all i want to thank all of you for the service that this comunity gives in order to solve our daily 'tiny' problems.
Well, i am new in this forum and i expect i could help you in another sittuation.
In this time i have a little problem:
I need to comunicate a XC167CI microcontroller from Infineon with a GSM modem GDW-11 from Westermo via RS232.
First at all, i established the properties of the comunicattion RS232 in the modem by means of the SW of Westermo.
Then, i tried to send AT commands from Hyperterminal to the modem and i could generate calls, send sms and have a complete communication between Hyperterminal and Modem.
My problem starts when i want to communicate the microcontroller with the modem. i have programmed the microcontroler and i sent it the next commands:
printf("ATD 654789879"); putchar(0x0D);
and....nothing happens...
In order to proof the commands generated by the micro, i have connected the microcontroller with Hyperterminal to see what the microcontroller send to the hyperterminal. In the hyperterminal screen i could see the commands correctly sent by the micro, ATD 650987987
So...i suppose the microcontroller generates a good command. However,when i connect the microcontroller with de modem the LEDs TD and RD don't shine. So, it means that there are not transmition between them, and then, the modem doesn't execute the commands
I don't understand why my microcontroller comunicates with the Hyperterminal, Hyperterminal comunicates with modem with the same commandas but...microcontroller doesn't connect with modem.
I would be very grateful if someone could give me any idea.
I am a bit lost because i am not sure where could be the problem.
thank you a lot and sorry for the long question!
thank you a lot for your interest!
i have configured the modem without handshaking....so..when i try to send commands with hyperterminal, there are no handshaking and it works....but...it doesn't work with the micro.
Maybe the problem it's about the modem is ignoring the serial port because it has some LEDs indicating several aspect and two of them refers to the communication progress, LED TD and Led RD
In this sense, when i use hyperterminal, both of them star shining each time i introduce a character in hyperterminal but....they don't shine when i pass the command through the serial port.
" have configured the modem without handshaking....so..when i try to send commands with hyperterminal, there are no handshaking"
Are you sure? Have you tried using a cable with just the three wire Tx, Rx, and GND - and only those three - connected?
Are you sure that you have Tx and RX correctly connected from your microcontroller - remember that Tx is an input to a DCE (modem).
You are using a proper RS232 transceiver with the microcontroller, aren't you?
Have you tested with a scope to see what's happening?
Hello!
When i use a three wire cable, it works with Hyperterminal when i configure it without handshaking...good...however...it still doesn't work with microcontroller....
I use a MAX232 driver to convert the signal provided by the micro to the serial port. I have connected the max232 as you can see in this figure, and i have also shortcouted pins 7 and 8 to avoid handshaking.
www.coolcircuit.com/.../max232_small.gif
thanks!!
Are you sure that you have Tx and RX correctly connected from your microcontroller? Remember that Tx is an input to a DCE (modem).
yes yes yes yes!!! i have used a cross cable beetwen micro and modem and all works......u can't imagine how grateful i am with all of u!!
Please to meet u and hope that sometime i could help u!!