A small gadget to monitor the power supply and enclosure temperature of your Raspberry.

My Raspberry Pi server host a OpenVPN service, Onion Pi Tor proxy access point, and EasyIOT.

The power supply come from a old Pc, and the enclosure from a plexi-glass slab.

It’s based on Arduino, so there is no schematic, sketch is available here, it’s just a Atmega328P with a DS1820 temperature sensor,
analoginput A0 is used to monitor Vcc power supply through a voltage divider.
I2C interface for LCD2x16 is wired to A4/A5 pin. You will need <LiquidCrystal_I2C.h>, <OneWire.h> libraries.

You can defined the threshold in the code, to monitor Vcc value, more or less than 5 volts for example, that the same for temperature.

Alert will be displayed on the screen, also a digitalwrite() (choice what pin you want), can drive a fanless, LED, relay to off the power-supply, or drive a Raspberry  I/O pin (emergency power-off, email alert …)

Gerber file available