Hi everyone
I tried the Sim800l module with uno but no luck. Then to test it I connected it to my laptop via a pl2303 serial/usb converter. With the AT command I get a bunch of different responses: OK, [no response], RDY and sometimes a "ý" (ascii 152) character. Sometimes it returns the current network which sim is registered but as I send the same command again, it respond with ERROR or an unexpected result mentioned above.
I used a 3.7v lipo battery and tested it for current and that was also ok. Tried different baud rates and a resistor voltage devider on rx pin also tried software flow control on and off, but still don't know what's wrong.
Your help is much appreciated.
You have some hardware you didn't post a link to connected to your PC using some device/circuit you didn't post a link to/a schematic for, and you send something somehow to the device, and you do or do not get the expected response.
What, exactly, was your Arduino question?