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gsmsim900

Strange encoded response to AT commands

I get strange encoded messages from my sim900 module when I enter AT commands. I have set the baud rate to 9600. I've tried using several terminals but to no avail.

Any help is appreciated.

Thanks

Solution

  • I am quite sure the issue is with baud rates. Your terminal baud rate should be set to the baud rate of the module. There can be one of the followings issues with your setup

    • Your sim900 module is set to another baud rate (try 115200)
    • You are not sending \r at the end of your commands
    • Your sim900 is in auto-baud state and is waiting for AT\r command to lock in to the baud rate you are communicating in. In this state you need to send AT in uppercase a few times after the modem switches ON.