AttributeError: 'NoneType' object has no attribute 'send' pigpiod

Question

So I create an another program that can run stepper motor clockwise and counter clockwise with a ramp up and ramp down in there and adding limiter switch on GPIO 16 and 26 to stop the pi.wave_send_using_mode(wid2, pigpio.WAVE_MODE_ONE_SHOT_SYNC) giving a chain wave, this is my code:

import time
import pigpio

START_DELAY=600
FINAL_DELAY=500
STEP=1

GPIO=20

pi = pigpio.pi()

pi.set_mode(GPIO, pigpio.OUTPUT)
pi.set_mode(21, pigpio.OUTPUT)
pi.set_mode(26,pigpio.INPUT)
pi.set_mode(16,pigpio.INPUT)
#pi.write(21,1)
pi.wave_clear()

statee = 0
try:
    while True:

        pi.write(21,statee)
        pi.wave_clear()

        wf=[]
        offset = pi.wave_get_micros()
        for delay in range(START_DELAY, FINAL_DELAY, -STEP):
           wf.append(pigpio.pulse(1<<GPIO, 0,       delay))
           wf.append(pigpio.pulse(0,       1<<GPIO, delay))

        for i in range(500):
            wf.append(pigpio.pulse(1<<GPIO, 0,       FINAL_DELAY))
            wf.append(pigpio.pulse(0,       1<<GPIO, FINAL_DELAY))
        wf.append(pigpio.pulse(0, 0, offset))

        for delay in range(FINAL_DELAY, START_DELAY, STEP):
           wf.append(pigpio.pulse(1<<GPIO, 0,       delay))
           wf.append(pigpio.pulse(0,       1<<GPIO, delay))

        pi.wave_add_generic(wf)

        wid2 = pi.wave_create()

        #pi.wave_send_once(wid2)
        pi.wave_send_using_mode(wid2, pigpio.WAVE_MODE_ONE_SHOT_SYNC)

        if pi.read(26) == 0:
            pi. wave_tx_stop()
            pi.stop()
        if pi.read(16) == 0:
            pi.wave_tx_stop()
            pi.stop()

        time.sleep(0.75)
        if statee == 0:
            statee = 1
        elif statee == 1:
            statee = 0
except KeyboardInterrupt:
    print ("\nCtrl-C pressed.  Stopping PIGPIO and exiting...")
    pi.wave_tx_stop()
    pi.stop()

the problem happen when the mottor run arround 5 - 10 minutes, I give an error message like this:

Traceback (most recent call last):


File "/home/pi/Desktop/ramp.py", line 49, in <module>
    if pi.read(16) == 0:
  File "/usr/local/lib/python3.4/dist-packages/pigpio.py", line 1401, in read
    return _u2i(_pigpio_command(self.sl, _PI_CMD_READ, gpio, 0))
  File "/usr/local/lib/python3.4/dist-packages/pigpio.py", line 989, in _pigpio_command
    sl.s.send(struct.pack('IIII', cmd, p1, p2, 0))
AttributeError: 'NoneType' object has no attribute 'send'

So, what the cause of error in my code? Is that cause by pi.read(26) and pi.read(16)? Is there any other ways to stop or terminate pi.wave_send_using_mode(wid2, pigpio.WAVE_MODE_ONE_SHOT_SYNC) at the middle of it process? thank you small note: I set pigpiod daemon start on boot by folow (How to Run pigpiod on boot KimSJ answer), is the method of runimg pigpiod cause this error? thank you

Answer 1

It may be the pi.stop() causing the problem. I'm not sure what you intend but that terminates the connection to the pigpio daemon.

I think you should comment out the calls to pi.stop() after pi.read(26) and pi.read(16).

Answer 2

Most likely cause I can see: you have a rogue space in line 49:

pi. wave_tx_stop()

should be

pi.wave_tx_stop()