Using mkr board to control the gain of a turbidity sensor

I am using an MKR board to control the gain of a turbidity sensor. There are 4 gains and 2 control lines. The two control lines of the sensor are internally pulled up to 5V so the 4 gains can be achieved by pulling the control lines low or leaving them in their pulled up state at 5V.

My question is; can this be achieved by simply setting a pin as output and then pulling the pin low which will pull the gain line low however how do i allow the pin to float so as to leave the gain line in its pulled up state or is just setting the pin high OK? Do i need to have a diode or maybe a resistor on the output of the pin to protect it?

Note that i am trying to avoid having to use relays.

Any help is much appreciated.


It's likely that the sensor can be controlled directly by a microcontroller but without a datasheet you can't be sure.

If the sensor is 5V and your MKR board is 3.3V you'll need some transistors between the two.

This topic was automatically closed 120 days after the last reply. New replies are no longer allowed.