Hello,
I’ve been building a project using the Clipper LTE Breakout connected to a Raspberry Pi Zero 2W via UART (GPIO14/15), with PWRKEY on GPIO27 and RESET pulled high to 3.3V.
The module was working perfectly responding to AT commands, registering on the network and sending data over LTE. However after connecting a Waveshare UPS HAT (C) for Pi Zero alongside it, the module stopped responding entirely.
The UPS HAT uses pogo pins to power the Pi from below, which I now believe may have caused a conflict with the 5V power rail. I have since removed the UPS HAT but the Clipper no longer responds to any AT commands, even with a minimal setup of just the Pi Zero 2W and Clipper connected.
I’ve tried:
- Toggling PWRKEY (GPIO27) low for 2 seconds then high
- Sending AT commands via Python’s pyserial on /dev/ttyAMA0 at 115200 baud
- Reseating the JST-SH connector and all Dupont wires
- Reinserting the SIM card
- Confirming VDD is connected to 5V and VDDIO to 3.3V
The module returns no response at all. There is no visible LED activity on the board.
Is there any way to diagnose whether the module has been damaged? Could the dual 5V power supply situation have caused damage to the LTE module?
Any help would be greatly appreciated.