Unable to get multiple PWM pins to work simultaneously

Robotics & Edge Computing Jetson & Embedded Systems Jetson Orin Nano
5

Hi topherbuckley,

Your behavior is caused from the flow you configure the PWM.

Please refer to the following modification in your python script

    # Pin Setup:
    # Board pin-numbering scheme
    GPIO.setmode(GPIO.BOARD)
    # set pin as an output pin with optional initial state of HIGH
-   GPIO.setup(pwm_pins, GPIO.OUT, initial=GPIO.HIGH)

    _frequency_hz = 50
    _duty_cycle_percent = 25
    incr = 5

    # p1 is a PWM object.
    # ERROR the order of the p1 and p2 initialization determines which one works
    # and which one fails. Whichever is initialized last will work, and whichever is
    # first will fail. (verified with oscilloscope and stepping through with pdb). 
+   GPIO.setup(pwm_pins[0], GPIO.OUT, initial=GPIO.HIGH)
    p1 = GPIO.PWM(pwm_pins[0], _frequency_hz)
    p1.start(_duty_cycle_percent)
+
+   GPIO.setup(pwm_pins[1], GPIO.OUT, initial=GPIO.HIGH)
    p2 = GPIO.PWM(pwm_pins[1], _frequency_hz)
    p2.start(_duty_cycle_percent)
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