Spurious signals on empty ADC channels
Hello friends at Pimoroni and users everywhere.
I just installed an Automation hat to read 24V
digital signals from out Fanuc robot.
It works like a charm, excellent.
HW: Automation HAT, Raspi 3, latest raspbian updated & upgraded.
Used the easy curl-installation script.
- three digital 24vdc robot output lines connected to
automation hat input lines
- HAT GND plane connected to robot signal ground
- everything works perfectly
- I connected the raspi 5V from screw terminal to
ADC line 1 and got the voltage ok.
- however I get spurious readings from empty lines
(with led flashes) ADC 2 & 3
- this is not an issue, I’m super happy with digital
input, very nice!
- I must be missing something fundamental here?
So comments would be extra nice, please?
all the best
Pete (Pekka) Kyrenius
Aalto University FINLAND