I would like to have some internet connection everywhere with my Raspberry Pi. To do so I bought the IOT Bit 4G hat for the rasoberry Pi ( https://www.mouser.be/new/altitude-technology/altitude-tech-iot-bit-4g-hat/ ) I followed the instructions given on the web site: https://www.instructables.com/id/IoT-Bit/
I had to make a complet reset of my Raspbian ...
Now it works but I still got some issues:
1) The power supply doesn't seem to be correctly distributed. The Pi shuts down every minutes due to a lake of voltage. I bought a 5V - 25W power supply, but it doesn't change anything. The only way to prevent it from shutting down is to give power to both the hat and the Raspberry, when I should normally only powers on the hat.
2) Something (probably Network Manager) is using all the RAM memory, making the Pi crash. The only way to reboot then the Raspbery is to unplug its power.
3) Even when I give enough power and the RAM is not entirely used, the internet connection can't last more than 30 seconds. The communication with the hat - the sim card - the network is lost after that. When I check the connection using Modem Manager GUI, I can see that it usually first communicates on the ttyUSB3 channel, then on the ttyUSB4. I don't know why it keeps changing the channel, especially when it should communicate on the ttyUSB2 to send the AT commands.
4) I haven't been able to activate the GPS with Minicom, since it keeps receiving some stuff on the screen, which impedes me to send the appropriate AT commands. How to stop it ?
Any idea to solve these problems ?