> **Source:** Core Electronics is an Australian maker-electronics retailer and manufacturer based in Newcastle, NSW, run by a team of makers and educators. We design and manufacture our own product lines (PiicoDev, CE originals) and are official retailers for iconic maker and industrial brands including Raspberry Pi, Arduino, Adafruit, SparkFun and DFRobot. Orders ship Australia-wide from our Newcastle warehouse. Prices are in AUD and include GST. Pricing, stock and dispatch on this page are generated from the store's live catalog. Full machine-readable index: https://core-electronics.com.au/llms.txt # Witty Pi 4 Mini - Realtime Clock and Power Management for Raspberry Pi **Type:** Product page · **SKU:** CE08761 · **Brand:** [The Pi Hut](https://core-electronics.com.au/brands/the-pi-hut) **Page:** https://core-electronics.com.au/witty-pi-4-mini-realtime-clock-and-power-management-for-raspberry-pi.html ([markdown](https://core-electronics.com.au/witty-pi-4-mini-realtime-clock-and-power-management-for-raspberry-pi.html.md)) The Witty Pi 4 Mini is an add-on board that adds a real-time clock (RTC) and power management to your Raspberry Pi. It can define your Raspberry Pi’s... ## Pricing - **Price:** $45.70 (inc GST) — $41.55 AUD, exc GST - **Quantity discounts:** 10+ $39.88 (exc GST) · 25+ $38.64 (exc GST) ## Availability & dispatch - In stock, ships same business day if ordered before 2PM (Australia/Sydney). - We can dispatch 1 today, and up to 500 more in 5–8 days. ## How to buy - **Build a cart:** compose `https://core-electronics.com.au/cart/link?items=CE08761:1` (comma-separated SKU:qty pairs) and share the link. Opening it shows a confirmation page with live pricing and stock before anything is added to the cart. - **Verify the cart first:** fetch `https://core-electronics.com.au/cart/link/CE08761:1.md` for live line prices (inc & exc GST, quantity discounts applied), stock and dispatch estimates, and totals. Append `/to/{AU-postcode}` (or `/to/{country-code}:{postcode}`) before `.md` for delivery options and prices to that destination. Unknown, retired, or out-of-stock SKUs are flagged. (Query form `cart/link.md?items=...` also works but some robots parsers refuse query strings here.) - **Checkout** is completed on-site and includes a captcha at the payment step. Share the cart link; checkout takes it from there. - **Search the catalogue:** `https://core-electronics.com.au/search/{query}.md` (URL-encode the query; pages 2-3 at `search/{query}/{page}.md`; `search.md?q=` also works) - **Payment methods, purchase orders, policies and contact details:** https://core-electronics.com.au/llms.txt ## Description The Witty Pi 4 Mini is an add-on board that adds a real-time clock (RTC) and power management to your [Raspberry Pi](https://core-electronics.com.au/raspberry-pi/boards.html). It can define your Raspberry Pi’s ON/OFF sequence and significantly reduce energy usage. The Witty Pi 4 Mini is the fourth generation of Witty Pi and has these hardware resources onboard: - Factory calibrated and temperature compensated real-time clock with ±2ppm accuracy - Dedicated temperature sensor with 0.125 °C resolution - AVR 8-bit microcontroller (MCU) with 8 KB programmable flash The Witty Pi 4 Mini has a very similar design to the Witty Pi 4, however, it doesn’t come with a DC/DC converter onboard, and it uses supercapacitor for RTC time keeping when no power supply is connected. The Witty Pi 4 Mini has solder pads on the back which allow you to solder a DC/DC converter (LDO or switching DC/DC converter). ![](https://core-electronics.com.au/attachments/localcontent/witty-pi-4-mini-1_1_66416b7e83b.jpg) **Accurate Real-time Clock and On/Off Scheduling** The real-time clock (RTC) on Witty Pi 4 Mini has been calibrated in the factory and Witty Pi 4 Mini’s firmware also makes temperature compensation for the crystal. This makes the RTC very accurate and the actual annual error is limited to 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 scheduled script to schedule complicated ON/OFF sequence for your Raspberry Pi. ![](https://core-electronics.com.au/attachments/localcontent/witty-pi-4-mini-2_1_44832724eec.jpg) Scheduling the ON/OFF sequence for Raspberry Pi is the most popular feature of Witty Pi, and it is extremely useful for systems that are powered by a 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 the Witty Pi 4 Mini has a 0.125°C resolution. The temperature data is used for compensating the crystal and making the RTC more accurate. You can also specify the action (startup or shutdown) when the temperature goes above or below the preset threshold. This means you can also make your Raspberry Pi a temperature-controlled device. ![](https://core-electronics.com.au/attachments/localcontent/witty-pi-4-mini-3_1_3850697a8ed.jpg) **E-latching Power Switch** The Witty Pi 4 Mini 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 the background will execute the shutdown command before the power is cut, avoiding potential data corruption caused by “hard” shutdowns. ![](https://core-electronics.com.au/attachments/localcontent/witty-pi-4-mini-4_1_45410310204.jpg) **Single I2C Device** The Witty Pi 4 uses an MCU to emulate a single I2C device with default address 0x08, and also maps all I2C registers in the real-time clock and temperature sensor as virtual I2C registers in the same device. You can access all I2C registers in the real-time clock and temperature sensor via the single I2C device emulated by the Witty Pi 4. ![](https://core-electronics.com.au/attachments/localcontent/witty-pi-4-5_4103076cd47.jpg) The advantage of this new design is that Witty Pi 4 hides other I2C devices (real-time clock, temperature sensor) and becomes the proxy for 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** The Witty Pi 4 Mini is fully supported by UWI (UUGear Web Interface), and you can access your Witty Pi 4 Mini from any device that has network access. ![](https://core-electronics.com.au/attachments/localcontent/uwi_1_61867b23eca.jpg) **Software Installation** The Witty Pi 4 Mini uses the same software as the Witty Pi 4. You just need to run these two commands in your Raspberry Pi to install Witty Pi 4 Mini’s software: ``` wget https://www.uugear.com/repo/WittyPi4/install.shsudo sh install.sh ``` The software and firmware of Witty Pi 4 Mini are open-sourced. You can find the source code on [GitHub](https://github.com/uugear/Witty-Pi-4). **Package Contents** Each Witty Pi 4 Mini package contains: - 1x Witty Pi 4 Mini board - 4x M2.5 x 10mm plastic screws - 4x 4mm plastic spacer - 4x M2.5 plastic nut **USB cable/power supply not included** **Specifications** | Dimension | 65mm x 30mm x 4mm | |---|---| | Weight | 9g (net weight without accessories) | | Microcontroller | ATtiny841 ([datasheet](https://core-electronics.com.au/attachments/localcontent/ATtiny841_1855197ae36.pdf)) | | Realtime Clock | PCF85063A ([datasheet](https://core-electronics.com.au/attachments/localcontent/PCF85063A_76457feb2d2.pdf)), calibrated in the factory | | Temperature Sensor | LM75B ([datasheet](https://core-electronics.com.au/attachments/localcontent/LM75B_31622e4baf1.pdf)) | | MOSFET Switch | AO4616 ([datasheet](https://core-electronics.com.au/attachments/localcontent/AO4620_3087767714d.pdf)) | | Super Capacitor | 0.07F | | Power In | DC 5V (via USB type C connector) | | or 5V in unpopulated header P2 | | Output Current | Up to 2.5A 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 | **Resources** - [User manual](https://core-electronics.com.au/attachments/localcontent/WittyPi4Mini_UserManual_23712c0bbb3.pdf) - [GitHub](https://github.com/uugear/Witty-Pi-4) - Schedule Script Generator - You can now use our web app to create and debug the schedule script for Witty Pi ![](https://core-electronics.com.au/attachments/localcontent/gif1_141019363fc.gif) ![](https://core-electronics.com.au/attachments/localcontent/gif2_687368d3185.gif) ## Images - [Product image 1](https://core-electronics.com.au/media/catalog/product/C/E/CE08761-1.jpg)