Arduino millis catch overflow how to#
Arduino millis catch overflow serial#
Arduino millis catch overflow code#

Arduino millis catch overflow code#

I think I have made the code where overflow is not an issue, but if someone disagrees, please let me know. Truth be told, handling the rollover does my head in I've read several articles on it - but invariably they all seem to deal with the problem from an interval perspective - and when that interval isn't fixed but varies depending on other inputs - but is calculated from something that also relies on millis() then it gets to a level I just can't get my tiny brain around. Whereas both the LED and the CR servo cycle between two states, the pair of positional servos goes through many states ( 92 240 if I counted correctly).

But exactly when owerflow happens, blynk shows the Heartbeat timeout message. For the positional servos, the same principle can still be applied, but there is a catch. My app perfectly works during that 4294967 milliseconds. For now ESP32 has only 4294967 milliseconds (about 71 minutes) from the start before millis () overflow happens. So in that context it just doesn't matter. Hello, I got the strange behaviour of the ESP32 millis () overflows and the blynk Heartbeat timeout. In my case it - literally - means that if my electric blanket had been on for 59 days straight (highly unlikely) then out of every 16 second cycle it might remain off for a few seconds when it should have been on - or vice-versa before the 'old value' also rolls over. So I'm not suggesting that 'using millis() to calculate can always be used to calculate the time of some future event' and 'just ignore the rollover' - I'm really just saying that one just needs to be aware of it - and that in real world terms (I think) it's OK to ignore it if there aren't going to be any real-world consequences (which I suspect could often be made part of the design). if you start at 10 count back to 0 then 255 on down you will see that the answer is exactly 20. 10 - 245 > 20 Millis() has just rolled over startTime was before rollover. To be honest I didn't examine the code in detail. millis() - startTime > interval Lets try it using byte to make the math easier. If (pumpFlag = pumpIsOn & millis() - pumpOnMillis >= 5000) If (pumpFlag = pumpIsOff & millis() - pumpOnMillis >= 10000) You should be able to build something from this example: //Version YY/MM/DD Description Remainder = (nextTime - currentTime) / 1000

Arduino millis catch overflow serial#

Uneven pumping intervals while printing 'remainder' time to Serial Monitor

Arduino millis catch overflow how to#

The real purpose of the code is to water plants every 12 hours with a water pump and to be kept on for months at a time.Ĭan someone please review the code and provide recommendations regarding how to avoid the following command: 'if (currentTime > nextTime)' which will not work once the first value overflows? The example of code I found will be prone to millis() overflow after the ~50 days I believe. I am trying to create a program that can run uneven intervals (ie turn an LED on for 5 seconds and off for 10 seconds) without using the delay() function.