Hi, i'm currently setting up a Raspberry Pi 4B, together with a Witty Pi4 and a Waveshare SIM7600G-H 4G HAT to create a Offside/Remote-Data Uploader for localized Weatherdata. I got the mobile-network stuff figured out and working already, so i'm now tackling servicing & intervalls.
The goal is to keep the Waveshare Hat always powered on and using its RI output, when a message/call is received as a signal for the Witty Pi on the SW-Pin to turn them on, in combination with its schedule scripts.The Data connection would be directly via USB to the Pi.
My initial idea was to stack the hats ontop of eachother, but theres booth a GPIO Pin issue (which could be resolved), as well as a powering issue as the Witty Pi does not troughput any power, when its off, so the Sim Hat would be off too. At least to my knowledge.
However i found out, that it could be possible that the 5V on the P2 Pins, when its powered trough USB-C could troughput/output 5V. As this is something i'm quite unsure about, as there are no schematic available regarding the layout for this part of the circuit, i thought before i go forward with it, i should ask.
The alternative would be a second power brick, just for the Sim Hat.
Thank you very much in advance, i hope my intend is understandable.
Best,
Chris
Yes, the 5V pin on P2 is directly connected to the USB-C 5V input. As long as USB-C power is present, the 5V on P2 remains available, even when Witty Pi 4 has turned off the power to the Raspberry Pi.
The 5V pin on P2 was originally designed as an alternative 5V power input. However, due to the direct connection, it should also be possible to use it as a power output.
Please note that we have not tested your particular hardware combination and cannot guarantee that the complete setup will work as expected. You will need to verify the power requirements and compatibility of your system yourself.
@admin Thank you very much for the fast help, that is really great to hear!
I will check and test everything regarding this particular setup and put the results here soon once done, for other users to find.