I Surrender

I finished coding the motor/sonar board and tested the software.

I used serial print and the built in LED to indicate the sonar and command/motor status.

The sonar and motors work as expected separately but when combined too many false sonar triggers.

I am wondering if motor noise and/or vibration are triggering the sensors?

The ESP12-E is not that stable as well (it can stop working) suggesting electrical problems still exist.

Many months ago I had a remote control test bed that worked fine.

I have spent months trying to get the HC-SR04 working with the test-bed.

It seemed at the time adding sonar would be a small job.

What when wrong? I still don't understand!

Yes, the steppers somehow destroyed four HC-SR04s.

The servo certainly did take out two HC-SR04s and a 6.2v 1W zener (lucky it did not take out everything).

Learnings

Anything inductive needs special attention to the power supply, you have to consider inductive kick-back.

Better to build a separate motor controller and even a separate motor power supply.

Better to delegate software duties (i.e. use a master-slave setup) as managing everything on one MPU is difficult (particularly the ESP-12E).

Find a replacement for the HC-SR04!

I will return with a new plan of attack but after Halloween, AlanX