<![CDATA[Creating an infinite async loop]]>Looking to write code that will send data via mqtt perpetually. Learn recently that the publish() method is NOT synchronous, which I augmented by listening to a topic for an ack message before calling the iteration done, and the next iteration publish begins.

So I tried to close the loop by calling the publish() method within the subscribe() handler, and the app crashed with message 'RuntimeError: maximum recursion depth exceeded'.

How do people get around this?

]]>https://community.m5stack.com/topic/2044/creating-an-infinite-async-loopRSS for NodeWed, 29 Apr 2026 00:41:02 GMTSun, 14 Jun 2020 11:15:52 GMT60<![CDATA[Reply to Creating an infinite async loop on Mon, 15 Jun 2020 15:45:27 GMT]]>@m5stack I will share pseudo-codes of the current implementation, which is stable so far:

CycleTimer = Timer(-1)

def main():
  # init and connect mqtt client
  doCycle()

def doCycle():
  global CycleTimer
  # send stuff from mqtt
  # NOTE: do not use machine.lightsleep() as publish() is NOT synchronous
  # lightsleep() will block data from being sent
  CycleTimer.init(period=5000, mode=Timer.ONE_SHOT, callback=doCycle)

NOTE: this is power-intensive; calling lightsleep() will cause uiflow's mqtt client to crash quickly.

]]>https://community.m5stack.com/post/9010https://community.m5stack.com/post/9010Mon, 15 Jun 2020 15:45:27 GMT<![CDATA[Reply to Creating an infinite async loop on Mon, 15 Jun 2020 09:53:41 GMT]]>could you share your code to here. maybe people can help you.

]]>https://community.m5stack.com/post/9008https://community.m5stack.com/post/9008Mon, 15 Jun 2020 09:53:41 GMT<![CDATA[Reply to Creating an infinite async loop on Sun, 14 Jun 2020 16:33:51 GMT]]>Am trying using ONE_SHOT timers. Not sure if this is the recommended approach.

]]>https://community.m5stack.com/post/9002https://community.m5stack.com/post/9002Sun, 14 Jun 2020 16:33:51 GMT