DMW1001 Dev - DW1000 GPIO's 5 & 6

Hi all,

I am having a problem with TWR between two DWM1001 devices.
I have ported the TREK1000 RTLS application to each of the devices with some success.

The problem I’m having is that the my anchor never receives TAG_FINAL message from my tag. I have tried sending the TAG_FINAL with DWT_START_TX_DELAYED and DWT_START_TX_IMMEDIATE but it seems that the receiver on my anchor is not on when this FINAL message is sent from the tag.

I found in the APS022 document that you can probe DW1000 GPIO’s 5 & 6 to look at the RX & TX on times. But I could not find in the DWM1001 Dev schematics where I can probe this.

Are these pins available to probe on the DWM1001? If not, how can I fix/look at the timings of send/receive states?

Thank-you for your help.

Kind Regards,

Hi there,

if you take a closer look at the DWM1001 Schematic (sheet 4) you can see that GPIO5 and GPIO6 are connected to T2 and T3, respectively.

But I guess you have to take off the metallic cover to access them, but remember the nRF is photo sensitive, so make sure to put the cover back on before turning the module on (if not it is gonna work like a crazy drunk µproc).

1 Like

Thanks for the reply.

Yes, I saw that on the schematic and was hoping that I was reading it wrong. I don’t really want to take off the metallic cover for fear of damaging the board.

Would have been good to have a TP on the dev-board, but can’t win them all! :slightly_smiling_face:


If you can modify the code, you can toggle a GPIO out of the nRF processor every time you enter or exit transmit or receive. Add a GPIO pin state change instruction when sending the SPI commands to change state. You can’t tell about internal state transitions in the DW1000, but this will at least confirm your receiving module did or did not enter receive mode when the transmitting module initiated transmit.

Also, DW1000 GPIO2 (RXLED) and GPIO3 (TXLED) are pinned out to DWM1001 pins. This can be used to detect transmission and reception of packets. See GPIO_MODE register in user manual.

GPIO0 (RXOKLED) and GPIO1 (SFDLED) are also available on DWM1001 module pins.

Mike Ciholas, President, Ciholas, Inc
3700 Bell Road, Newburgh, IN 47630 USA
+1 812 962 9408

Anyone knows if I could I use GPIO2 and GPIO3 as UART pins for another module on my custom board? If yes what’s the configuration needed?