The SIM800L is a very popular and tested module. Many of us have used it in multiple projects and have not faced any problems with it. The problem you are facing may be caused due to a defective module, incorrect connections or coding. Better to debug and identify this issue and then take a call on ...

The documentation and the circuit for this board are available here - https://github.com/Xinyuan-LilyGO/TTGO-T-Display As per the circuit diagram, you can power your TTGO T-Display using the battery shield. The TTGO TDisplay has an internal voltage regulator that converts the 5V to 3V3. The connecti...

Try getting a good power supply that can handle 1A of current.

If that doesnt work, erase flash and upload the firmware to the ESP32 again.