Buildbotics Forum

Hi,
I am building a cnc and now I'm looking for proximity sensor. Is there any reason why using npn and not pnp?

thx

The limit switch outputs connect directly the AVR microprocessor outputs. You can use any type of proximity sensor that you want as long as it never connects the output from the BB Controller to more than 3.3 Volts or less than 0 Volts.