How to order Contact us Distributors Reviews
Register / Login

Select currency

If you'd like to view estimated pricing in other currencies then please select a currency below below.

GBP USD EUR JPY AUD NOK CHF NZD CAD

Please note:

  • Currency conversions are estimates and for information only
  • Your order will be billed in GBP
  • All prices exclude VAT / other local sales taxes
  • Shipping calculated during checkout


Witty Pi 4: Realtime Clock (RTC) and Power Management for Raspberry Pi

by UUGear
An image of Witty Pi 4: Realtime Clock (RTC) and Power Management for Raspberry Pi An image of Witty Pi 4: Realtime Clock (RTC) and Power Management for Raspberry Pi An image of Witty Pi 4: Realtime Clock (RTC) and Power Management for Raspberry Pi An image of Witty Pi 4: Realtime Clock (RTC) and Power Management for Raspberry Pi An image of Witty Pi 4: Realtime Clock (RTC) and Power Management for Raspberry Pi An image of Witty Pi 4: Realtime Clock (RTC) and Power Management for Raspberry Pi An image of Witty Pi 4: Realtime Clock (RTC) and Power Management for Raspberry Pi An image of Witty Pi 4: Realtime Clock (RTC) and Power Management for Raspberry Pi

Witty Pi is an add-on board that adds realtime clock and power management to your Raspberry Pi.

It can define your Raspberry Pi’s ON/OFF sequence, and significantly reduce the energy usage. Witty Pi 4 is the fourth generation of Witty Pi and it has these hardware resources onboard:

  • Factory calibrated and temperature compensated realtime clock with ±2ppm accuracy.
  • Dedicated temperature sensor with 0.125 °C resolution.
  • On-board DC/DC converter that accepts up to 30V DC.
  • AVR 8-bit microcontroller (MCU) with 8 KB programmable flash.

ACCURATE REALTIME CLOCK AND ON/OFF SCHEDULING

The realtime clock (RTC) on Witty Pi 4 has been calibrated in the factory and Witty Pi 4’s firmware also makes temperature compensation for the crystal. This makes the RTC very accurate and the actual annual error is limited within ±2ppm. When your Raspberry Pi boots up, the time stored in the RTC will overwrite the system time. As a result, your Raspberry Pi knows the correct time even without accessing the Internet. You can schedule the startup and/or shutdown of your Raspberry Pi, and make it a time-controlled device. You can even define a schedule script to schedule complicated ON/OFF sequence for your Raspberry Pi.

Scheduling the ON/OFF sequence for Raspberry Pi is the most popular feature of Witty Pi, and it is extremely useful for systems that powered by battery. By only turning on Raspberry Pi when necessary, the battery can be used way much longer with Witty Pi installed.

TEMPERATURE CONTROLLED DEVICE

The temperature sensor on Witty Pi 4 has 0.125 °C resolution. The temperature data is used for compensating the crystal and make the RTC more accurate.

You can also specific the action (startup or shutdown) when temperature goes above or below the preset threshold. Which means you can also make your Raspberry Pi a temperature-controlled device.

DC/DC CONVERTER AND E-LATCHING POWER SWITCH

Witty Pi 4 comes with a DC/DC converter on board, which allows you to power your device with 6~30V power supply. You can also power your device with 5V via the USB type C connector.

Witty Pi 4 also implements an e-Latching power switch, which is very similar to the power switch on your PC/Laptop computer. You can gracefully turn on/off your Raspberry Pi with a single tap on the button. The software running in background will execute the shutdown command before the power gets cut, this avoid the data corruption caused by hard shutdown.

Witty Pi 4 supports all Raspberry Pi models that has the 40-pin GPIO header, including A+, B+, 2B, Zero, Zero W, Zero 2 W, 3B, 3B+, 3A+ and 4B. You will need to solder the 40-pin header to Zero/Zero W/Zero 2 W model beforehand, so they can make reliable connection with Witty Pi.

SINGLE I2C DEVICE

Witty Pi 4 uses MCU to emulate a single I2C device with default address 0x08, and also map all I2C registers in realtime clock and temperature sensor as virtual I2C registers in the same device. You can access all I2C registers in realtime clock and temperature sensor via the single I2C device emulated by Witty Pi 4.

The advantage of this new design is that Witty Pi 4 hides other I2C devices (realtime clock, temperature sensor) and becomes the proxy of them to talk to Raspberry Pi. Because the I2C address used by Witty Pi 4 can be changed to any value, you can always avoid the I2C address conflicting.

UWI SUPPORT

Witty Pi 4 is fully supported by UWI, and you can access you Witty Pi 4 on any device that have network access.

SOFTWARE INSTALLATION:

You just need to run these two commands in your Raspberry Pi to install Witty Pi 3’s software:

pi@raspberrypi:~ $ wget https://www.uugear.com/repo/WittyPi4/install.sh
pi@raspberrypi:~ $ sudo sh install.sh

The software and firmware of Witty Pi 4 are open-sourced. You can find the source code on GitHub.

PACKAGE CONTENT:

Each Witty Pi 4 package contains:

  • Witty Pi 4 board x 1
  • CR2032 battery x 1
  • M2.5 x 11mm Copper Standoff x 4
  • M2.5 screws x 8

SPECIFICATION:

Dimension 65mm x 56mm x 19mm
Weight 23g (net weight without accessories)
Microcontroller ATtiny841 (datasheet)
Realtime Clock PCF85063A (datasheet), calibrated in factory.
Temperature Sensor LM75B (datasheet)
DC/DC Converter MP4462 (datasheet)
MOSFET Switch AO4616 (datasheet)
Battery CR2032 (for time keeping when power supply is disconnected)
Power In DC 5V (via USB type C connector)
DC 6V~30V (via XH2.54 connector)
Output Current Up to 3A for Raspberry Pi and its peripherals
Standby Current ~0.5mA
Operating Environment Temperature -30°C~80°C (-22°F~176°F)
Humidity 0~80%RH, no condensing, no corrosive gas

USER MANUAL

More information about this product can be found in its user manual

Reviews

User photos

Witty Pi is an add-on board that adds realtime clock and power management to your Raspberry Pi.

WITTY_PI_4

You must register for an account and be logged in to view pricing or place an order on the Pimoroni Wholesale store.

If you represent a school or university, a business, or reseller of Maker products then you can sign up for a wholesale account.

If you already have an account you can login to your account here.

Alternatively the easiest way to get your hands on the products we offer is to order them directly from our customer facing online store.

SKU
WITTY_PI_4
EAN
0769894022139
Brand
UUGear
Stock available
0 units
Backorder not allowed on this product
Weight
34g

Video introduction

Guides & tutorials

Search

 

Region

Your search returned no results.

Subscribe

We'll keep you up to date with new product launches!

The good ship

We've been sailing the Maker seas offering our wares since 2012.

  • read about our history
  • what our customers say
  • find a local distributor
  • contact our business team

We manufacture all of our products locally at our workshop in Sheffield, UK

Under one roof

Pimoroni are your one-stop shop for bulk and education purchasing of Raspberry Pi, Pimoroni, micro:bit, Adafruit, Sparkfun, and many other brands.

If you have any questions about what we offer then drop us a line.

Pimoroni Ltd

Unit 1, Parkway Business Park,
Parkway Drive,
Sheffield,
S9 4WN,
United Kingdom

Registered in England and Wales:
Company №: 07510759
VAT Reg №: GB 140 8707 21