From the photo here you will see the Wirgrid Debug Board is just an FTDI FT232BL chip which is a USB Serial/UART. The board also has two switches: RESET and BOOT.
The debug header on the gateway itself has a 3.3V TTL UART. You can use a normal USB Serial dongle to connect to it - doesn’t need to be a FT232BL. Any USB UART module should work.
The pinout of the header on the gateway is as follows, with pin 1 closest to the Test button, and pin 8 closest to the Reset button. You’ll note that only every other hole has a metal pin. So count zig-zag from right to left to right.
2 # O TEST
- Vcc?? - unsure about this
- Looks like Reset
- TX (connect to dongle RX)
- RX (connect to dongle TX)
- Looks like Boot
- Ground (connect to dongle ground)
Using this I was able to open a terminal using
screen /dev/ttyUSB 115200 with the gateway.