Getting errors with SIM800L and Arduino


#1

Hi, I have installed the library Hologram-SIMCOM and running the sketch ‘Blink’,
I have set the device key and this is the output I am receiving:
DEBUG: Verbose monitoring and modem serial access enabled
DEBUG: Write Modem Serial = AT

DEBUG: Modem Serial Buffer = AT
DEBUG: Modem Serial Buffer = OK
DEBUG: Write Modem Serial = AT+IPR=19200

DEBUG: Modem Serial Buffer = AT+IPR=19200
DEBUG: Modem Serial Buffer = OK
DEBUG: Write Modem Serial = AT+CPIN?

DEBUG: Modem Serial Buffer = AT+CPIN?
DEBUG: Modem Serial Buffer = ERROR
ERROR: Error resp when calling AT+CPIN?

ERROR: begin() failed at +CPIN
Cellular connection failed
Setup complete

I have tried to look up why the ERROR is appearing but I could not find any reason, any help would be appreciated :slight_smile:


#2

I was getting similar problems and also created a post. Assuming you have the SIM in the right way and you are in an area that has 2G coverage, I am really not sure what the problem is. I got it working once or twice but going back to it, it would stop working. The best results I got was to use a terminal program and enter the AT commands by hand!

I have since moved on and use the NOVA with its 4G coverage and have much more success with the tutorials.


#3

I have tried typing the AT commands manually, the problem is that similar to the log I have posted, for basic commands such as reading states I get as a response “ERROR”, how could I troubleshoot it if I can’t even read stuff from the module?
And thank you,I will try to make use of your post.

Update: Okay, so if I flip the SIM orientation, I get this on the init:
DEBUG: Write Modem Serial = AT

DEBUG: Modem Serial Buffer = AT
DEBUG: Modem Serial Buffer = OK
DEBUG: Write Modem Serial = AT+IPR=19200

DEBUG: Modem Serial Buffer = AT+IPR=19200
DEBUG: Modem Serial Buffer = OK
DEBUG: Write Modem Serial = AT+CPIN?

DEBUG: Modem Serial Buffer = AT+CPIN?
DEBUG: Modem Serial Buffer = +CPIN: READY
DEBUG: Modem Serial Buffer = OK
DEBUG: Write Modem Serial = AT+CSQ

DEBUG: Modem Serial Buffer = AT+CSQ
DEBUG: Modem Serial Buffer = +CSQ: 0,0
ERROR: no signal
Cellular connection failed

And when I flip it back I get 25,0 for AT+CSQ but same errors as I posted above.
Also, Sometimes it outputs SMS ready, no idea what that means.


#4

I got +CPIN:ERROR in two occasions

  1. inverted SIM
  2. bricked/broken SIM (I forgot to unplug/power off the board before re-inserting SIM).

Since SIM800L is a 2G modem, it is only bound to connect to a 2G cell tower. However, knowing that modem will try to get the connection with the higher transmission power, then your SIM800L might jump from a 2G to a 3G tower… which will result in inconsistent network connection.
AT&T retired 2G network already so SIM800L is just supported by T-Mobile until end of 2018 (or just a few years more).

As @Steve_Mayze suggested, try to use SIM 3G modules instead, specially if you’re just into the proto stage.


#5

Hey, I tried the sim on my phone and its working, signal is 20,0 without sim and 0,0 with, any suggestions?


#6

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.