I have a device that continuously sends the signal of different pulse widths. I am trying to read those pulse duration and build my logic to further implement it. It is a synchronous signal.
I am using raspberry pi zero w and using GPIO 4 to read the signal using the monitor.py code.
However when i see the oscilloscope trace it is clear and the minimum duration is 1000micros.
But when i am reading the values, in between it gives me 50, 250, 90 and so on.. the values are inconsistent. And the output seems not to be synchronous.
Since it a synchronous signal the start is detected by a long Low duration of 63ms. But I am not getting the desired output when i run monitor.py
Below is my monitor.py code:
Below is my output:
G=4 l=1 d=62295
G=4 l=0 d=1321
G=4 l=1 d=5
G=4 l=0 d=444
G=4 l=1 d=5
G=4 l=0 d=2056
G=4 l=1 d=3065
G=4 l=0 d=1019
G=4 l=1 d=870
G=4 l=0 d=6
G=4 l=1 d=2189
G=4 l=0 d=1020
G=4 l=1 d=3066
G=4 l=0 d=304
G=4 l=1 d=5
G=4 l=0 d=770
G=4 l=1 d=3005
G=4 l=0 d=426
G=4 l=1 d=5
G=4 l=0 d=564
G=4 l=1 d=5
G=4 l=0 d=20
G=4 l=1 d=1020
Those 3 digit numbers are undesirable. I am not able to figure out what is going wrong.
I am using raspberry pi zero w and using GPIO 4 to read the signal using the monitor.py code.
However when i see the oscilloscope trace it is clear and the minimum duration is 1000micros.
But when i am reading the values, in between it gives me 50, 250, 90 and so on.. the values are inconsistent. And the output seems not to be synchronous.
Since it a synchronous signal the start is detected by a long Low duration of 63ms. But I am not getting the desired output when i run monitor.py
Below is my monitor.py code:
Code:
# monitor.py# 2016-09-17# Public Domain# monitor.py # monitor all GPIO# monitor.py 4 # monitor GPIO 4import sysimport timeimport pigpiolast = [None]*32cb = []def cbf(GPIO, level, tick): if last[GPIO] is not None: diff = pigpio.tickDiff(last[GPIO], tick) if diff >= 59000: # Check if difference is greater than or equal to 59000 print("G={} l={} d={}".format(GPIO, level, diff)) else: # Print other differences print("G={} l={} d={}".format(GPIO, level, diff)) last[GPIO] = tickpi = pigpio.pi()if not pi.connected: exit()# Check if GPIO 4 is specified in the command line argumentsif len(sys.argv) == 1 or '4' in sys.argv: cb.append(pi.callback(4, pigpio.EITHER_EDGE, cbf)) try: while True: time.sleep(60)except KeyboardInterrupt: print("\nTidying up") for c in cb: c.cancel()pi.stop()Below is my output:
G=4 l=1 d=62295
G=4 l=0 d=1321
G=4 l=1 d=5
G=4 l=0 d=444
G=4 l=1 d=5
G=4 l=0 d=2056
G=4 l=1 d=3065
G=4 l=0 d=1019
G=4 l=1 d=870
G=4 l=0 d=6
G=4 l=1 d=2189
G=4 l=0 d=1020
G=4 l=1 d=3066
G=4 l=0 d=304
G=4 l=1 d=5
G=4 l=0 d=770
G=4 l=1 d=3005
G=4 l=0 d=426
G=4 l=1 d=5
G=4 l=0 d=564
G=4 l=1 d=5
G=4 l=0 d=20
G=4 l=1 d=1020
Those 3 digit numbers are undesirable. I am not able to figure out what is going wrong.
Statistics: Posted by Axon_11 — Wed Apr 24, 2024 2:18 am