Adafruit
Witty Pi 4 HAT - RTC & Power Management for Raspberry Pi
The Witty Pi 4 is a Raspberry Pi HAT that adds a precision real-time clock, power management, and scheduling capabilities. Define ON/OFF sequences to signifi...
Get notified when back in stock
The Witty Pi 4 is a Raspberry Pi HAT that adds a precision real-time clock, power management, and scheduling capabilities. Define ON/OFF sequences to significantly reduce energy usage in battery-powered systems, or use temperature thresholds to trigger automatic startup and shutdown.
A built-in DC/DC converter accepts 6–30V DC input, and an e-latching power switch provides graceful shutdown — just like a PC power button. The board also supports 5V input via USB Type-C.
Key Features
- Real-Time Clock – Factory calibrated, temperature compensated, ±2 ppm accuracy
- Temperature Sensor – 0.125 °C resolution, usable for temperature-triggered actions
- DC/DC Converter – Accepts 6–30V DC input
- E-Latching Power Switch – Graceful shutdown via single button tap
- ON/OFF Scheduling – Time-based and temperature-based startup/shutdown sequences
- MCU – AVR 8-bit microcontroller with 8 KB programmable flash
- Single I²C Device – Default address 0x08 (configurable), proxies RTC and temperature sensor
- UWI Support – Web-based management via UUGear Web Interface
Compatibility
- Raspberry Pi A+, B+, 2B, 3B, 3B+, 3A+, 4B
- Raspberry Pi Zero, Zero W, Zero 2 W (requires soldered 40-pin header)
- Raspberry Pi OS (other Linux distributions may require manual configuration)
Installation
wget https://www.uugear.com/repo/WittyPi4/install.sh
sudo sh install.shPackage Contents
- 1× Witty Pi 4 board
- 1× 30 cm 22AWG XH 2.54 cable
- 4× M2.5 × 11 mm copper standoffs
- 8× M2.5 screws
Resources
Jargon buster
Plain-language definitions for the technical terms used above.
- AVR
- AVR is a family of 8-bit microcontrollers (made by Microchip, formerly Atmel) used in many classic Arduino-style boards such as the Uno and Nano. They are widely supported but older, which can be a limit for memory- or speed-intensive tasks.
- DC
- DC means direct current, where electricity flows in one constant direction, as supplied by batteries, USB ports and many plug-pack power supplies. When a product specifies DC, it runs from a DC supply rather than mains AC, so you need to provide the correct voltage and polarity.
- M2.5
- A metric screw thread size with a 2.5 mm nominal diameter. It matters for mounting because screws, standoffs, and holes must use the same size to fit securely without damaging the board.
- microcontroller
- A microcontroller is a small computer on a single chip that runs a stored program and controls connected inputs and outputs such as buttons, sensors, displays and communication interfaces. In a device built around one, it is the part that executes the code and coordinates the device's behaviour.
- ppm
- ppm means parts per million, a common way to express very small gas concentrations in air. For CO₂ sensors, the ppm range tells you what levels the sensor can measure, such as normal indoor air through to poorly ventilated spaces.
- RTC
- A Real-Time Clock keeps track of time even when the main processor is asleep or powered down, usually with a small backup battery. It matters for data logging and tracking projects that need accurate timestamps.
- USB Type-C
- USB Type-C is a small, reversible USB connector used for power, data and sometimes video on many modern devices. The connector itself does not guarantee a particular speed or voltage, so check the supported USB version, data rate and whether it carries more than 5V via USB Power Delivery.
Find this product in
Brands
Raspberry Pi
