sim900 factory reset without AT command [closed]

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I made a mistake when I was setting the baud rate of the SIM900 module. I set it as 600 (instead of 9600) that is not standard baud rate. So, I don't have access to the AT commands to change it with AT+IPR or even factory reset by AT command. Does anybody know how I can reset the module to factory setting or a way to be able to send connect to serial port of the module with this wrong baud rate.

Thanks.

Answer 1

Download hyperserialterminal, and set your baudrate to 600 on the application. Then send your AT commmands.

Answer 2

if I remember fine, if you set a non acceptable serial speed value, this value is ignored, so ERROR string should be appear after your settings... anyway, try to send about 20/30 times AT command at 4800 baud after that, send AT+IPR=9600 (to set up the serial speed), followed by a sequence of 20/30 AT command. So power off / power on the modem and your modem should be recovered ....

If you are unable to communicate, then try this AT sequence, remember to wait OK string receiving before sending next AT command:

1) ATE0

2) AT+IPR=9600

3) Send 20/30 AT sequence (not for all AT cmd you'll receive OK, this sequence need for modem calibration)

4) ATE0&W

If after this sequence you'll are still unable to communicate with the modem, try to send:

AT+IPR=0

followed by 20/30 AT cmd sequence ... this setting puts the Modem serial speed to fabrication default value.

Hope this help you.

Answer 3

Try http://m2msupport.net/m2msupport/module-tester/ which is a great standalone application for serial testing and shall open perfectly in your browser (I used firefox and it won't work in chrome) and may need a latest jre version on your machine.

I was stuck will similar problem as I set the baud rate of my sim 900A to 1200. I was unable to get change it using putty and even hyperterminal until I found this.

Answer 4

I had exactly the same problem with my SIM900 after setting AT+IPR=115200. It would not even power up. Every time it tried it immediately shut down, so I couldn't communicate with it. I couldn't find a hardware reset on the board so I thought it was trashed. I spent about 30 mins searching the net for answers, found nothing useful, so I unplugged all of the link wires between the SIM900 and my Arduino, pulled the CR1220 battery out of the socket, powered up again and it worked. Woooohooooo. Give it a try.Ebay cheap SIM900