Witty Pi is an add-on board for Raspberry Pi that brings real-time clock (RTC) and power management functionalities to your Raspberry Pi. It can define the on/off sequence of your Raspberry Pi, perform power on/off actions based on temperature or voltage thresholds, and significantly reduce overall energy consumption.

Witty Pi 5 HAT+ is the fifth generation of the Witty Pi product line and the first Witty Pi board to comply with the Raspberry Pi HAT+ specification.

As a Mode 1 Power HAT+ board, Witty Pi 5 can deliver up to 5A current to Raspberry Pi and its peripherals.

Witty Pi 5 supports all Raspberry Pi models with a 40-pin GPIO header, including A+, B+, 2B, Zero, Zero W, Zero 2 W, 3B, 3B+, 3A+, 4B, and 5B. For models like Zero, Zero W, and Zero 2 W, you will need to solder a 40-pin header onto the board beforehand to ensure a reliable connection with Witty Pi.

Witty Pi 5 includes the following hardware features:

• A high-precision real-time clock, with an accuracy of ±3.8 to 5 ppm.
• A dedicated temperature sensor with 0.0625°C resolution.
• An onboard DC/DC converter that accepts up to 30V DC input.
• Two “ideal” diodes that isolate V_IN and V_USB
• An RP2350 microcontroller (MCU) with an external 16MB flash memory.
• An ID EEPROM compatible with HAT+ specification.

Witty Pi 5 is also more developer-friendly for firmware and software customization. Both its firmware (written in C using the pico-sdk) and its software (written in C) are fully open-source, allowing users to modify and adapt them as needed. You may find Witty Pi 5’s Firmware Repository and Software Repository on GitHub.

Just like other RP2350-based boards, firmware updates are very easy: by holding the BOOTSEL button while connecting the USB cable, the RP2350 enters USB boot mode and presents itself as a virtual USB drive. You can then drag-and-drop the compiled .uf2 firmware file to flash it.

Witty Pi 5 also emulates both a USB flash drive and a USB serial device. This allows users to edit configuration files, view logs stored on the board, and monitor real-time logs via the serial interface—all of which lower the barrier for development and debugging.

Note: Coin cell battery is not included to make shipping a lot easier for folks abroad. You can get one locally or add one from the Adafruit shop, if you need.