Trying to set up PJRC's Teensy 4.1 instead of an Uno with the SIM7000A. This board doesn't support 5V logic, so I'm hoping to have this run off 3.3V. The trace shorting 5V pad to logic level select has been cut, and VCC has been shorted to the central pad.
Is it correct that 5V will need to be supplied to the SIM7000A 5V pin still to charge the battery? Schematic shows a short between SIM 7000 5V pin and VIN of the MCP73831, but I'm concerned this will in someway affect the logic levels in a way I'm not currently measuring.
Does the SIM7000 retain commands like AT+IPR=9600 across power cycles? I'm having issues running hardware serial at 115200, but 9600 works fine. The code looks like while SS starts at 115200, it cuts to 9600 quickly with no confirmation communication at 115200 actually occurred.
EDIT: Also of note, with the MQTT example modified for the Teensy, with hardware serial the code gets stuck in the loop attempting to enable GPS, while software serial doesn't exhibit this behavior.
Thank you! Great shield and appreciate it being open source.
Your wiring should be what your wrote, except you should connect 3.3V (Teensy) to 5V on the shield to set the logic voltage to 3.3V, UNLESS you cut the logic voltage selection jumper as explained here.