Hazard of some DWM1001 tags in low power mode?

I found a problem with DWM 1001 in tag low power mode.
I test PANS R2 in configuration 6 anchors, 6 tags and 2 bridge with RPI. Everything seemed okay until I noticed that one node in tag low power mode periodically joined and unjoined from PANS (cca 30s). I examined all the nodes in detail and found this behavior in four (from 12)

In other modes (responsive tag, anchor ) nodes works correctly. This behavior is the same with both the original FW and the user modified FW, is independent of HW (chande DWM1001 between two HW and the behavior is reversed), after entering to shell mode the problem will stop (probably nRF52832 is not in stop mode).

Behavior after reset is following:

  • reset blik all led
  • 1s green LED on and red LED blik according to update rate (corect behavior)
  • 20s leds off , tag is unjoined from PANS (any modules go to directly to reset)
  • 12s reset, blik all led
  • cyclic the same

The module goes into hazard when switching to low power mode (20 s after reset).

It can’t be a coincidence (4 modules from 12). I don’t know where the problem (HW, calibration of modules …??)

No one observed this behavior? Help.


Does that happens only on low power tags ? What update rate are they configured with ?


Yes, only in low power tag mode (the other modes are OK, I think it’s related to sleeping in low power mode). This behavior is independent on rate update (0,1sec to 60sec). When I wake up module (sendig any byte to UART) behavior is correct.

Each module in low power tag mode go to sleep 20sec after reset. Bad modules 20sec after reset go to hazard. Problem is switch to sleep .

Regards Daniel