SIM800L Sleep Mode

I am having some trouble with my SIM800L module. Basically I set the DTR pin to high and then used AT+CSCLK=1\n to put the module into sleep mode. Then, to wake it up I tried to set the DTR pin to low and send AT+CSCLK=0\n to the module but nothing happened. I have also tried to call the module and send AT+CSCLK=0\n again, but it still didn’t work. My power source showed a rise in current usage but it went back to sleep right after the call ended.

You are not doing it fast enough :slight_smile:
Keep sending AT commands in loop when it wakes up. Then when it responds OK, Send the AT+CSCLK=0 command. I would advice to use CSCLK=2.

But does SIM800L support CSCLK=2, it doesn’t say anything about it in its datasheet. Thank you!