Witty Pi 4 L3V7 - RTC & Power Management for Raspberry Pi

Witty Pi 4 L3V7 is an add-on board that adds real time clock and power management to your Raspberry Pi. It allows defining your Raspberry Pi’s ON/OFF sequence and significantly reduces energy use. Designed to work with 3.7V Lithium ion or polymer batteries, it also functions as an Uninterrupted Power Supply (UPS).

The board fits Raspberry Pi models with a 2x20 connection header and comes in a 'micro Hat'/'bonnet'/'pHat' format.

Note: 3.7V nominal Lithium Ion or Polymer battery is not included. Proper battery polarity is crucial to avoid damage.

Key Features:

• Factory calibrated and temperature compensated real time clock with ±2ppm accuracy
• Dedicated temperature sensor with 0.125 °C resolution
• AVR 8-bit microcontroller with 8 KB programmable flash
• DC/DC step-up (boost) converter outputting up to 5V/3A
• Charging manager that can charge a battery up to 1A
• Built-in uninterruptible power supply (UPS) functionality
• Accurate RTC and on/off scheduling for Raspberry Pi
• Temperature controlled device functionality
• E-latching power switch for graceful power on/off
• Single I2C device emulation for easy communication
• Full UWI support for remote access

Technical Details:

• Dimensions: 65mm x 30mm x 7mm
• Weight: 10g (net weight without accessories)
• Microcontroller: ATtiny841
• Real-time clock: PCF85063A (factory calibrated)
• Temperature sensor: LM75B
• DC/DC Converter: MP3423
• Charging Manager: TP4056
• Power Input: DC 5V (via USB-C) or 3.7V Lithium ion/polymer battery
• Output Current: Up to 3A
• Standby Current: ~0.3mA on battery, ~1mA on USB-C 5V
• Operating Environment: -30°C to 80°C, 0-80% RH

Software installation requires Raspberry Pi OS; use the install script available on the official website. Source code and firmware are open-source on GitHub.

Witty Pi 4 L3V7 User Manual (PDF)