Dear
I wanted to ask you the following, a while ago I made a device with blynk and a nodemcu ESP8266 the interface to connect a PT100 industrial sensor, because the sensor works resistively, and is powered with 24V, I connected it to port A0 through of a bridge formed by a 220ohm resistor (connecting on side A the negative output of PT100 and A0, and on side B -24V of the source and GND. Then with a digital sensor I simultaneously measured the temperature and the values from the PT100, and I made an interpolation. I then used this interpolation in an Arduino code to read the data from the PT100 with BLYNK. It works quite well. A0 is 8 bits, I have interpolated values from 0 to 1024.
The problem is that I need to do the same with the ESP32, but in principle in addition to using a different scale from the ADC 0 to 4095, with several resistors I have tried and the results are not fixed like the esp8266, but vary, it seems prone to noise , and I have also read that it must be closed. I would like to know if anyone has any ideas to make it work well with the PT100.
first of all, Thanks…
RUBEN MEDINA.
• Hardware model ESP32