Hello all, I am trying to build a button box using PCF8575 IO expanders and I am seeing a bunch of confusing posts all with different opinions on how to wire them and code them.
Hardware I am planning on using:
Buttons
PCF8575
Switches
controllers
This is the wiring diagram ive worked up. I am not an electrical guy, I am a software guy by trade. But Ive recently seen something about needing to add a resistor between the controller and the SDA and SCL pins? Any advise you could give me here would be valuable.
Project Description:
I am using 7x ON-ON SPDT switches, that is the Orange dots representing the 2 pins per switch for inputs.
I am using 18 LED momentary Push buttons. Button inputs are blue, LEDs that wont be lit up by power supplied to the buttons are represented in Green.
3 of those buttons I want to always be lit, the other 15 buttons are sorted into four Button Group that I only want to be lit up when certain conditions are met: ie IF(PF8575_one.pin10 == HIGH) then (controller.pin10 == HIGH)
I am unsure where 5v is on the controller, so the power is not connected there until i purchase everything and get readouts. Same for the Interrupt, which im not sure how to use anyway.
Anyways, any advise or alterations you think should be made, I would love to hear them. Pic of projected final project below:
