This question applies both to digital and analog inputs on the various ESP32 dev kits. From what I can tell, none of these boards (including my OLIMEX-EVB and Gateway boards) add any ESD protection to the bare ESP32.
So far I have had difficulty locating the proper Espressive data sheet to see what (if any) ESD tolerance there is. I suspect there is (the ESP8266 did) but I can't find it.
I have two specific applications I need to design for, and I am thinking both will work with a larger (e.g. 1 M Ohm) resistor:
A) Reading a digital input line for the open/closing of a limit switch.
B) Reading an analog input value on the ADC capable pins (which I think are 0-1.1v unless you use the attenuation function).
I am OK with a response rate as long as 1 second, although 1/10th of a second would be ideal.
So my questions are:
- Does anyone know what the ESD protection is on the bare ESP32?
- What is the best sized resistor to use to provide maximum protection and still have a decent response?
- Will thin film resistors work or do I need to get another type?