modem

I a doing a weird project, and looking to convert some short, simple datagrams to audio - send them over a (physical) radio - then to receive and decode them on another device (think - embedded devices with audio out jack and GSM/GPRS-type radios). (I have to use a physical, existing external radio). Does anyone know of a good, simple software modem library good for such a project? I'm not so concerned about data rate, and would prefer simplicity over functionality. Even something akin to a basic 1200 baud modem would be fantastic. Looking at this more of a learning experience and potential

I am sending USSD code on modem through serial port. But always it is giving ERROR in response. AT commands I am sending are: in sequence: serialPort.Write("AT+CMGF=0" + "\r\n"); serialPort.Write("AT+CUSD=1,\"*135#\"" + "\r\n"); when I am configuring message format in first AT command, it is giving 'OK' response. But on sending USSD code, response is always 'ERROR'. Why is it so? pumaikar Don't use \n in end of command, use only \r . Form of CUSD command is: AT+CUSD=1,"*135#",15 . In C# it should be: serialPort.Write("AT+CMGF=0" + "\r"); serialPort.Write("AT+CUSD=1,\"*135#\",15" + "\r");

I want to send / receive sms using AT commands from my computer to my mobile phone. I connected my phone to my computer using a USB port. My computer detects the modem and I am able to send sms from the computer to mobile phone. However, I am not able to receive sms in my computer.. I am presenting a sample of what I get from AT editor AT+CMGF=1 OK AT+CNMI=1,2,0,0,0 Error What can I do to send this prob and why am I getting this Error? Every phone has different capabilities so you should check which values for each parameter are valid for your phone by sending it a AT+CNMI=? For example my

I'm creating a php script that connects to a 3G modem connected via serial connection on COM5. I'm getting the following error and I believe it is because php does not have r/w access to COM5: Warning: fopen(COM5:) [function.fopen]: failed to open stream: No such file or directory in C:\xampp\htdocs\SMStest\test2.php on line 9 // mode com1: BAUD=9600 PARITY=N data=8 stop=1 xon=off $fp = fopen ("COM5:", "w+"); if (!$fp) { echo "Uh-oh. Port not opened."; } else { $e = chr(27); $string = $e . "A" . $e . "H300"; $string .= $e . "V100" . $e . "XL1SATO"; $string .= $e . "Q1" . $e . "Z"; echo $string

I've been trying to check my balance from by 3g modem via AT commands and seem to be stuck. The device infomation is as follows: Manufacturer: QUALCOMM INCORPORATED Model: M6281 Revision: SSD_M6281A-0.0.1 1 [Oct 02 2008 07:00:00] The modem has USSD capability (advertised and also present in the factory installed dashboard). I am connecting via putty to COM4 serial port which is my modems application port. All AT commands are working fine but I am getting an error on issuing the following via putty: AT+CUSD=1,"*111#",15 This returns a simple "ERROR". *111# is my carrier's balance check code. I

I want to send SMSs in PDU mode. I have checked the spec for my modem, and it supports PDU mode. I have developed a PDU encoder and decoder, but now I do not know how to send data to my modem. I tried these AT commands: AT AT+CMGF=0 after sending these commands I sent the PDU data like this: AT+CMGW="16079189390500410011000C918939050000000000AA02E834" I have checked the correctness of this PDU using this online tool : http://www.twit88.com/home/utility/sms-pdu-encode-decode but after sending it via the AT command, the modem hangs. Is this the right way to send SMS PDUs? I searched on Google

I am having a CRM (Customer Relationship Management Software) built on php and running it on localhost (windows XP system). This contains the list of my clients. I want to be able to call these clients directly from my CRM and keep a log of the same. (Call time, call duration and record the calls). For incoming calls, I should be able to link it to my CRM, display the client details and log the data. I have a voice enabled 3G GSM Modem (with USB connector) which can be used for this purpose. From my search, I understand I would need to send AT commands from PHP to interact with the modem. But