I am trying to provide a protection circuit for this device. When I tie to of the lines together, I am using 1 line as an Input Pin 9 (Monitor the +5V TTL signal) and the other as an Output Pin 3 (+5V TTL). All the circuit is supposed to stop the voltage coming from the Monitor line if it is configured as a Output, the line will blow up the box if they are connected and configured as both Outputs. My setup is pictured below. On the monitor line inside the device, it has a 10k pull up resistor that has my monitor line floating high all the time. Any ideas on how I can set this protection circuit to stop this floating voltage?
@Kasey, this is a Particle devices support forum and I’m not sure how your question pertains to this forum.