Hello. I want to use the CN0357 board with the sensor NH3-B1. I use an Arduino to communicate with the CN0357. The fact is that, this sensor is really different from the CO-AX. The CO-AX is an unbiased sensor but the NH3-B1 require 200mV bias voltage. How can I use it with the CN0357? Thanks
Hi RGERALDO386,
The current circuit has the working electrode biased at 1.2V provided by the voltage reference ADR3412.
The easiest way to provide a 200mV is to remove ADR3412 and provide an external reference in its place. But do take note that changing this changes the voltage reference of the ADC as well.
Regards,
Glenn
