GPIO Configuration for Hat

Would anyone be aware of the location for any documentation on configuring the 4G LTE Hat to operate over the GPIO connection to the PI?

I’ve tried a few things over the last few days but feel like I am missing something simple in the process that is resulting in problems with getting this set up. While the connection via USB has been enough to confirm the viability of the hat in the scenario we wish to use it, we are hoping that shifting over to a GPIO will allow us to use a housing with a smaller form factor for the overall build for our device.

Hi @i.doherty,

Please find the link to our documentation.
The pinout diagram shows the occupied pin among the 40 pin header. You can have access to the free GPIO pins. You can use UART(/dev/ttyS0) instead of USB to communicate with the HAT. The UART of Base HAT and mini PCIe are not connected by default. In order to use UART, you need to solder J7 and J8. When setting up the PPP connection just follow the steps there and select ttyS0.