ZOE-M8Q PPS

Qwiic System
1

Hi! I have a problem shown in the picture with the PPS sign. In High frequency is nice rectangular sign (but why go under 0V ?!), but at a lower frequency terrible… I tried with 2 NEO-M8Q

The power is good (+/- 20mV noise).

With SparkFun_u-blox_GNSS_Arduino_Library/Example23_TimePulseParameters (v 2.2.22) it running without error message. I tried it with with SparkFun_u-blox_GNSS_v3, but nothing happens…

TimePulse_Frequency_ino_2000Hz_1000Hz .jpg
TimePulse_Frequency_ino_2000Hz_1000Hz .jpg2560×1080 298 KB

TimePulse_Frequency_ino_20Hz_10Hz .jpg
TimePulse_Frequency_ino_20Hz_10Hz .jpg2560×1080 305 KB

2

How is the scope connected to the module? Almost looks like a missing ground

3

The scope ground is on the common (power) ground.

4

I just noticed that the scope is set up for AC coupling. Try changing it to DC coupling.

/mike

5

Mea culpa… :oops:

I misinterpreted a parameter, so The PPS signal has not changed for a long time.

Then I switched to AC coupling…

It works excellent with good settings.