I'm currently looking at using an Arduino Nano for a computer desk I'm building - using it as a sort of KVM switch between the desk PC and a laptop by connecting it to a couple of DisplayPort switches and a USB switch, and I'm struggling to read which "side" is currently in use (eg. PC or laptop). I'm pretty new to the electronics side of things, so apologies if I've left any key information out.
The components I'm using are as follows (from Amazon):
- CABLEDECONN DisplayPort 8K DP Switch x2 (I've read 3.3V from the switch)
- Arduino Nano ATmega328P and CH340
The schematic below shows how I'm trying to test the voltage. The part in the green box is the DisplayPort switch, and is on it's own PCB with external USB power, so they're connected to other parts I don't have the datasheet to. I'm just tapping into it by soldering some wires onto the board. When pressed and released, the switch turns one of the LED's off and the other one on to show which side is active.
When I try to connect the DP/USB LED’s to A0/GND, I’m not getting much sense from the values. One side reads ~660, then when I switch it the value fluctuates up and down from 0 to ~660. Any ideas where I go from here?
As an aside, when I attach a multimeter to the switch, it reads 0 when the button is closed and 3.3V when open, whereas the LED's read 1.4V when on and 0 when off.