SIM800L really works?



  • Hi, I have a module SIM800L for the M5stack. Does anyone use the SIM800L module? Sometimes it works, sometimes not. If I send a simple command like AT or something similar, no problem. But if I use an HTTP request or an other complex operation, sometimes it works and sometimes not. I obtain different errors from the module, but usually the errors are generic and not useful to understand where is the problem. If I use the same source code in a different module, for example a SIM808 or with an external SIM800L the code works well, when I use the SIM800L module with the M5stack I have the problems. Do you have some example of usage in a real environment, not sending simple SMS but something with GET or POST requests? I use a 5V 3A power supply (the official Raspberry PI 4 power supply) so I think I have enough current for the module. But I used also a 5V 2.4A mobile power supply with the same problems.
    I now ordered a new SIM800L module, maybe my module doesn't work well. I don't know what to think. Any suggestions or tips?



  • @robottini That would interest me, too.
    Is it also possible in Germany with a normal data sim card? Who has such a thing successfully on the run and can show example codes.
    I use MicroPython.


  • M5Stack

    I personally haven't been able to get it working in the UK, but I think that's simply because it's too complex for me to understand/debug. @Dimi our Russian colleague made some nice guide for us in Uiflow and Micropython showing how to use it http://forum.m5stack.com/topic/539/lesson-22-modules-sim800l
    and another guide here
    https://www.hackster.io/merryq/automation-with-sim800l-esp32-m5stack-170a82