@ESP_Alfred thanks very much for running the tests. I will rerun mine tonight with the volt meter disconnected and see what I get. I have also done some more testing on the issue where calling ADC read corrupts the memory and the esp goes into a continual crash. (BTW - let me know if you want me to open a seperate thread on this). I *think* it has something to do with the flash size. I have been using 1M (Esp 23f) without any problems. When I started using the ADC read it would kill the esp. The only way to get it back was to erase it with esptool and reflash the standard bin files you deliver BUT this will only work if flash size is 4M. Even doing this with a flash size of 1M fails. Using 4M flash size last night I was able to use ADC read with no issue and reflashed several times without issue.
It is almost as if the calll corrupts the flash somewhere after the 1M zone . I am fairly sure I can reproduce this at will so if you need me to run any tests to get to the bottom of the bug let me know. (Eg I read about String causing heap corruption due to using free instead is sys_free. Maybe ADC read does a similar thing
Thanks again both.
Lee.