I have built an MaxESP3 OnStep controller.
It works. Until...
At some point I updated the ESP32 from 3.16 to 4.24, but unfortunately I forgot to configure the N-S axis reversing, as needed. It happens.
I went out in the field on one of the few clear nights, happy as a daisy to test it out with some heavy weight instrument configurations.
While aligning the mount, I discovered to my surprise that I had completely forgotten to reverse the N-S axis.
I had my laptop with me, an USB cable and a screwdriver to take apart the OnStep box.
Powered off the box, pulled the cables from it, took it apart and extracted the ESP32 module.
Modified the code to suit my needs, compiled and uploaded into the module.
I put back the box, cabled it and powered on.
Following this, surprise no.2 of the evening - the WEMOS D1 mini 8266 comm module would not connect to the ESP32, so OnStep would not start. The blue led did not stop from blinking.
The WEMOS was sending ':GVP#' over the serial port, and the ESP32, when queried with ':GVP#' responded with 'On-Step'. But that was it.
After this, there is a very very long and tedious story, comprising of hours or checking, compiling, re-configuring the code, changing/downgrading the board versions in Arduino IDE (1.8.13) - with the same results, no connection between the ESP and the WEMOS modules.
What worked for me, as usual, was the last resort solution - I wrote into both modules some other, completely different sketch, with no connection whatsoever with the OnStep Project, and after that rewriting the modules with the OnStep code. FIY, for the WEMOS board the library used was 2.4.2 and for the ESP32 it was 1.0.4.
It did the trick.
Maybe it helps.
P.S. Why did all this happen? No idea. If someone can shed some light, please do.