Time Mark messages received without EXTINT trigger

GPS/GNSS
1

Hi,

I am using a GPS-RTK-SMA board with a u-blox ZED-F9P module. I want to trigger a time-mark message (UBX-TIM-TM2) by providing a signal on the EXTINT pin of the module.

According to the u-blox documentation, a rising or falling edge on the EXTINT pin should trigger the time-mark message. However, even without providing any external signal, I am still receiving Time mark messages when I power on the module.

I have multiple modules, but only one or two of them exhibit this behavior. The others work as expected.

Could this indicate a faulty module, or is there a configuration setting that needs to be corrected?

2

Hi Nayak,

Could it be electrical noise? What happens if you use a jumper wire to connect the EXTINT breakout pad to GND? Do the TIM-TM2 messages stop?

I hope this helps,
Paul