Regular interference at 60 minute interval.

[goingalong]

With the sensor powered from a Pi Zero I get a spurious detection every 60 minutes (to the second).

This spurious event appears to raise the 'O' output for approx 2.8 seconds each time.

I don't know of anything happening on the Zero at this sort of interval, nor anything happening at my property, so I assume it is coming in from outside. Maybe a neighbours WiFi ?

Has anyone else seen similar?

Test code is:

GPIO.setmode(GPIO.BOARD)
Motion_Pin = 11 #eg RCWL-0516 Microwave Radar Motion Detector
GPIO.setup(Motion_Pin, GPIO.IN, pull_up_down=GPIO.PUD_UP) # GPIO set as input

print('started @  ', dt.datetime.now().strftime('%Y-%m-%d_%H:%M:%S'))
while True:
    if GPIO.input(Motion_Pin) == True: #ie Rdr is triggered
        incident_time = dt.datetime.now().strftime('%Y-%m-%d_%H:%M:%S')
        incident_now = time.time()
        print('triggered ', incident_time)
        while GPIO.input(Motion_Pin) == True:
            pass
        print('ended ', time.time() - incident_now)

[gtoal]

Have you checked the log files on the Pi for cron activity coinciding with the interference?

Although remote meter reading such as water/gas/electricity is going on all around you, I don't know of any in that frequency band.

One possibility: "Earth exploration-satellite (active)", i.e. Star Trek-style sensors from space. The Earth is continuously scanned by military radar from space, I guess that allows them to see people moving inside buildings. Does the interference change with the orientation of your RCWL-0516? It does seem unlikely though that it would be on an hourly schedule.

From 47 CFR § 2.106 - Table of Frequency Allocations:

 G59 In the bands 902–928 MHz, 3100–3300 MHz, 3500–3650 MHz, 5250–5350 MHz, 8500–9000 MHz,
 9200–9300 MHz, 13.4–14.0 GHz, 15.7–17.7 GHz and 24.05–24.25 GHz, all Federal non-military [radiolocation]
 shall be secondary to military [radiolocation], except in the sub-band 15.7–16.2 GHz airport surface detection
 equipment (ASDE) is permitted on a co-equal basis subject to coordination with the military departments.

More info: https://library.nrao.edu/public/memos/evla/EVLAM_206.pdf Also you're not the first person to spot this: https://forum.arduino.cc/t/rcwl-0516-timed-false-triggers/598389