Running Uno R4 Wifi with an OLED, Twist, Red and Green Buttons on Qwiic. Everything runs great except the Green Button fails to start once every 3rd to 5th boot up. Unplugging and then rebooting the Uno is always successful. So, I concluded bad button or cable and replaced. Exact same performance. All other components always boot, only the Green does this…
How many of the i2c pull-up resistor sets are still active? How long are the wires?
Have not disabled any of the pull-ups, there’s 4 of the 2" wires.
The Green is more susceptible than the other components?
This might be a side-effect of green LEDs typically having higher forward voltage than red (and blue even higher! But we don’t make on of those currently)
If you test the green one by itself, what happens?
After playing around with various configs, it appears that when the OLED is on from a previous run, then the Green button will intermittently fail. On its own it starts well and with other Qwiic’s (limited testing) it also starts well.
Try putting the OLED at the beginning of the chain and compare with it being at the end of the chain of cables and see if anything changes
Try disabling all but one set of PU resistors…the OLED will look something like Qwiic Micro OLED Hookup Guide - SparkFun Learn, buttons as so SparkFun Qwiic Button Hookup Guide - SparkFun Learn and probably leave the twist’s set active and also re-test