Q1) What is the purpose of the power supply input on the board ? does it not just take power from the i2c port for the chips as this board does not produce power for the 4-20ma sensors?
Q2) Can you power the board from 3.3v so I can use a more powerful esp32 to interface on the I2C bus? eg so i dont have 5v i2c talking to a 3.3 controller.
Q3) If the external sensor fails (this happens) what protection is there is say 24v (Sensor power) is feed back to the board ?
Q4) is there a more specific data sheet for the product and not the individual IC’s that the unit uses?
For what you described I would recommend this product:
This product has an IoT interface socket which is compatible with our IoT interface modules. We offer an IoT Interface ESP32 module here which can be plugged directly into the board:
The most relevant documentation for this product is the Datasheet for the MCP3428 as that is the ADC connected via I2C used to monitor the 4-20mA inputs. If you can interact with that IC from the ESP32 then you can fully utilize the product. That data sheet is available here:
It is possible to power the board via the USB connection to the ESP32 in this instance however a power supply source to the board of 6-32VDC(12VDC nominally) is highly recommended.
If you have any other questions please let us know.