[How to do instruction] Use hardware momentary switches to control moOde

[Tim Curtis]

More info.

From (i) help in GPIO Config

- The GPIO button handler configures pins as input / pull-up.
- The pins are 3V3. Pins GPIO2 and GPIO3 have fixed pull-up resistors.
- At power on the pins are set to input mode, pins 0-8 are pull-ups to 3V3, pins 9-27 are pull-downs to 0V.

Power on state of GPIO pins
https://raspberrypi.stackexchange.com/qu...erup/51480

Rpi.GPIO - Configuring the pull up/down state in software.
https://sourceforge.net/p/raspberry-gpio...ki/Inputs/