Misc. Raspberry Pi Notes

This page covers some small, miscellaneous notes about the Raspberry Pi software.

Raspberry Pi OS

The Pi is running PiOS 11 Bullseye. SSH is enabled on the Pi, with the following login info:
USERNAME: printer
PASSW0RD: PrintMeBaby

Automatic WiFi Hotspot

Because the printer is controlled though the Mainsail web interface, an easy way to connect to the Pi's network is needed. Because the U.B. WiFi isolates devices for security, the Pi is configured to automatically create a WiFi hotspot on startup if no known WiFi network is available. This was done using this script. The installer was run using option 2, "Install Autohotspot with No eth0 for connected devices". The supplied crontab to run the service every 5 minutes was also used (present in the sudo crontab). The default gateway is 10.0.0.5. For now, the default hotspot name and password are used:
SSID: RPiHotspot
Pass: 1234567890

GPIO Power Switch

The Pi can be configured to use a GPIO pin as a power button to shutdown and boot the system. Some details can be found here, but to summarize, a line is added to /boot/config.txt that reads dtoverlay=gpio-shutdown. By default, this will cause GPIO3 (physical pin 5) to shutdown the Pi when pulled low. This is very useful for preventing corruption when needing to power off the Pi without access to a terminal to issue a shutdown command.