Hi I am fighting with the below issue since a long time and therefore any suggestion would welcome. I am using ESP8266-01 Upload of my sketch OK Reboot, then my sketch is working perfectly (e.g.

Next, we have our loop() section. In the loop section, we first check if the serial is available or not. ... In my project I am using Arduino Nano, ACS712 current sensors, and a MKS42 smart stepper ...

The sleep routine is a separate function, called from the main loop. As usual with Arduino, the ‘pin numbers’ aren’t the actual chip pin numbers, unless by coincidence. The led pin was correct for me, ...