ESP32 sometimes don‘t react to irq

Official Hardware Nano Family Nano ESP32
1

Hello all,

I got some strange behavior with my ESP32. Sometimes it feels like the controller fall asleep for a short time and reacts to a interrupt with a high time delay of around a second.

Background: I use a decoder to change the info on a LCD. Id the encoder counts one step an interrupt is raised and a callback function will change the LCD info.
There are some for-loops with a 10ms sleep. But I think the Interrupt will also be recognized if the controller is in a sleep state.
The time to transmit the info to the LCD is high of course and I know that the communication via I2C is slow. But if I add all the times to a sum I would expect a REACTION time of less than 100ms. And in most cases this is what happens. But sometimes I turn the decoder one step and put my hands away and then after a second the reaction happens. Have no idea what happens or what could delay the interrupt callback that way.
Do you have any ideas?

2

Check the pinned post on how to use the forum. CLUE, post ALL the code in code tags, post any error logs in code tags, post a wiring diagram (photo of hand drawn is fine)
Without seeing your code, I bet you have code inside the ISR. Simple solution is don't use delay, only set flag in ISR and do the processing in a millis controlled section.

3

Are you using an Arduino Nano ESP32 or some other ESP32?

4

Based on the code and schematic you posted, I’d take a SWAG (Scientific Wild-Assuming Guess) and suggest that you might be spending too much time in your ISR (Interrupt Service Routine).