Hey all I am wanting to make a project for this HDMI 5 port switch I have. I want to be able, with an Arduino, to detect which of the 5 ports are being used (only 1 can be used at any given time).
Without buying 5 of something like this to detect current (which would be ~$30):
Would it be possible for me to just purchase one of these and hook up different resistors values to each of the 5 LEDs and use the Arduino's Analog input to detect the voltage to determine which port LED was on?
I'm thinking that the standard red led voltage is around 2.0v? And the Android analog input is 5v. If this is possible then what type of values for the resisters for each of the 5 LEDs would be best to use in order to read the difference enough for each with the Arduino's analog input?
Example:
(com Gnd)-------------|
(led1)---/\/\/----\ | |----------------|
(led2)---/\/\/-----\ |---|[-] [vcc]-->to Arduino 5v Pin
(led3)---/\/\/------|-----|[+] [out]-->to Arduino Analog Pin
(led4)---/\/\/-----/ | [gnd]-->to Arduino Gnd Pin
(led5)---/\/\/----/ |----------------|
Or would this be possible without even using the current sensing module?
UPDATE
Ok how about if I used a 4N25 chip?
One of the LEDs would hook to Pin 1(+) and Pin 2(-). Pin 5 would house a voltage of ~3vdc from a power supply. Pin 4 would be hooked up to the arduino's Analog Pin 0.
So when the LED on the 5 port switch is powered on, it causes the ~3vdc power from the power supply to flow to the arduino where it's read as a voltage value.
Does this seem correct?