Yes 3.3v, that’s why I used a voltage divider. For the two further questions I’m not sure. How to check if it is open collector?
Probably in the specs. otherwise, you’d need to know the output chip to determine the type.
Alan KM6VV
I’ve think I’ve had a previous brush with an open collector setup. If the “open collector” is the same as I remember in the past, it will sink or source current/voltage depending on what the connected gizmo wants. One probably could test for this using a multimeter in the voltage measuring mode. If it is a problem then a diode or transistor setup could make it single direction.
I don’t have such detailed specs, and I don’t know much about the chip-set but only that the processor is Broadcom. I’m currently struggling with flu. I’ll return to this as soon as I debug flu from me out 