I recently purchased the Inventor’s Kit for RedBot. While setting up the RedBot and running through the example sketches, I found that the Reset button on the mainboard does not appear to be working properly. When pressed, there is no apparent effect - the current sketch does not rerun as expected. For example, when using the Experiment 4 example code from the Experiment Guide for RedBot, the wheels are expected to spin for 2 seconds then stop, which should then repeat when the sketch is reset. The wheels spin as expected when I first upload the sketch, but pressing the Reset button does not cause the sketch to rerun. Power-cycling the board through either the Power switch or by unplugging and reconnecting the battery pack does result in the expected sketch-reset behavior.
I’ve attempted to do some diagnostics:
However, the ground side of the switch appears to be floating, rather than connected to ground. I read no continuity between the ground side of the switch and the GND test locations of the board, and the voltage across the two sides of the switch reads a constantly-changing value of a few mV rather than the 5V I would expect. Further, if I hold the switch closed, the Rest pin of the ATMega is unchanged at +5V relative to GND and the ground side of the switch also goes to a steady +5V.
I tried double-checking the documentation, but electronics and electronic schematics are not my area of training, so it’s entirely possible that I am misreading the documentation. Reviewing the Eagle board schematic and the mainboard schematic on the RedBot Mainboard product page, I don’t see the Reset switch in the mainboard schematic (the ATMega Reset pin is tied directly to +5V through a 10kOhm pullup resistor, no switch), and the ground side of the switch does not appear to be connected to ground in the Eagle schematic.
Have I missed something obvious which explains the behavior I’m (not) seeing?