We have a number of M5Stack CoreS3 ESP32S3 loT Development Kit units, including a DIN base, for a product prototype.
We’ve also purchased 13 COM.LTE units from 2 different, Swedish, distributors.
And we have problems…
See text and image below.
Minor issue but still irritating. The mechanical tolerances of the DIN rail mount are such that it is unusable on all DIN rails we have tested (several). Perhaps DIN-rail specs are different in Sweden…. (probably not though).
Major issue with modem module.
The first 3 COM.LTE units we purchased work fine. I used the TinyGSM library with the ”SIM7600” header/spec. These units have a PCB that ”is aware” of the CoreS3 existence, see image, and also include a SIMCOM SIM7600G-H modem module.
The second set (10) of COM.LTE units ….
- The antenna cable on all units was connected to the contact marked GNSS. This is not correct!
- The PCB is most likely older. No CoreS3 ”marking”.
- The exact same code does not work!
Please note that the pin mapping from modem module UART RX/TX to the bus contact is the same on both PCBs ( I measured/tested) and the DIP-switch setting is the same.
Due to other sensor connections I want to keep the DIP-switch setting => I use GPIO 1 and 7 to communicate with the modem module. SERIAL_AT.begin(115200, SERIAL_8N1, 1, 7, false);
So now I have 10 COM.LTE units that do not work and I really don’t know what to do. Return/throw away/?
Perhaps someone has some tips
BTW1: Yes, I’ve tried miscellaneous modem test code from the TinyGSM library as well as even simpler code to test the UART connection.
BTW2, I’ve ordered 5 new COM.LTE units from distributor that supplied working units. We’ll see how it goes.
