DIY Kerlink Wirgrid debug probe


(repost of

If you happen to mess up the network or firewall config on your Kerlink gateway, the only way to get back into it is using a Wirgrid Debug probe. These things are really expensive and/or difficult to get your hands on. Looking at the photos of this debug probe one will see that it uses an FTDI FT232BL. This is a USB to serial chip which is very often used in USB to Serial/UART modules. This confirms that there must be a serial interface on the Kerlinkā€™s debug port. From experimentation I got a working terminal via the debug port using a Sparkfun FTDI basic breakout for 3.3V:

The pinouts of the debug header on the Kerlink itself I used are as follows:

# 1
2 #     O TEST
# 3
4 #
# 5
6 #
# 7
8 #
        O RESET
  1. Vcc?? - unsure about this
  2. Looks like Reset
  3. TX (connect to dongle RX) - reads as 3.3V on a multimeter, indicating 3.3V TTL logic - so use a 3.3V FTDI breakout.
  4. RX (connect to dongle TX)
  5. Looks like Boot
  6. Ground (connect to dongle ground)
  7. ??
  8. ??



Convert Actility Kerlink gateway to TTN