{"product_id":"witty-pi-4-mini-realtime-clock-and-power-management-for-raspberry-pi","title":"Witty Pi 4 Mini: Realtime Clock and Power Management for Raspberry Pi","description":"\u003cp\u003eWitty Pi 4 Mini is an uHAT shaped add-on board that adds realtime clock and power management to your Raspberry Pi.\u003c\/p\u003e\n\u003cp\u003eWitty 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 Mini is the fourth generation of Witty Pi and it has these hardware resources onboard:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eFactory calibrated and temperature compensated realtime clock with ±2ppm accuracy.\u003c\/li\u003e\n\u003cli\u003eDedicated temperature sensor with 0.125 °C resolution.\u003c\/li\u003e\n\u003cli\u003eAVR 8-bit microcontroller (MCU) with 8 KB programmable flash.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eWitty Pi 4 Mini has very similar design with \u003ca href=\"\/en-eu\/products\/witty-pi-4-realtime-clock-and-power-management-for-raspberry-pi\" target=\"_blank\" data-mce-href=\"\/en-eu\/products\/witty-pi-4-realtime-clock-and-power-management-for-raspberry-pi\"\u003eWitty Pi 4\u003c\/a\u003e, however \u003cstrong\u003eit doesn’t come with a DC\/DC converter onboard\u003c\/strong\u003e, and it \u003cstrong\u003euses super capacitor\u003c\/strong\u003e for RTC time keeping when no power supply is connected. 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) there.\u003c\/p\u003e\n\u003ch2\u003eACCURATE REALTIME CLOCK AND ON\/OFF SCHEDULING\u003c\/h2\u003e\n\u003cp\u003eThe realtime 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 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.\u003c\/p\u003e\n\u003cp\u003eScheduling 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.\u003c\/p\u003e\n\u003ch2\u003eTEMPERATURE CONTROLLED DEVICE\u003c\/h2\u003e\n\u003cp\u003eThe temperature sensor on Witty Pi 4 Mini has 0.125 °C resolution. The temperature data is used for compensating the crystal and make the RTC more accurate.\u003c\/p\u003e\n\u003cp\u003eYou 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.\u003c\/p\u003e\n\u003ch2\u003eE-LATCHING POWER SWITCH\u003c\/h2\u003e\n\u003cp\u003eWitty 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 background will execute the shutdown command before the power gets cut, and it avoids the data corruption caused by “hard” shutdown.\u003c\/p\u003e\n\u003ch2\u003eSINGLE I2C DEVICE\u003c\/h2\u003e\n\u003cp\u003eWitty 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.\u003c\/p\u003e\n\u003cp\u003eThe 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.\u003c\/p\u003e\n\u003ch2\u003eUWI SUPPORT\u003c\/h2\u003e\n\u003cp\u003eWitty Pi 4 Mini is fully supported by UWI (UUGear Web Interface), and you can access you Witty Pi 4 Mini from any device that have network access.\u003c\/p\u003e\n\u003ch2\u003eSOFTWARE INSTALLATION:\u003c\/h2\u003e\n\u003cp\u003eWitty Pi 4 Mini uses the same software as Witty Pi 4. You just need to run these two commands in your Raspberry Pi to install Witty Pi 4 Mini’s software:\u003c\/p\u003e\n\u003cp\u003e\u003ccode\u003epi@raspberrypi:~ $ wget https:\/\/www.uugear.com\/repo\/WittyPi4\/install.sh\u003cbr\u003epi@raspberrypi:~ $ sudo sh install.sh\u003c\/code\u003e\u003c\/p\u003e\n\u003cp\u003eThe software and firmware of Witty Pi 4 Mini are open-sourced. You can find the source code on \u003ca href=\"https:\/\/github.com\/uugear\/Witty-Pi-4\" target=\"_blank\"\u003eGitHub\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch2\u003ePACKAGE CONTENT:\u003c\/h2\u003e\n\u003cp\u003eEach Witty Pi 4 Mini package contains:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eWitty Pi 4 Mini board x 1\u003c\/li\u003e\n\u003cli\u003eM2.5 x 10mm plastic screws x 4\u003c\/li\u003e\n\u003cli\u003e4mm plastic spacer x 4\u003c\/li\u003e\n\u003cli\u003eM2.5 plastic nut x 4\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eSPECIFICATION:\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimension\u003c\/td\u003e\n\u003ctd\u003e65mm x 30mm x 4mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e9g (net weight without accessories)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMicrocontroller\u003c\/td\u003e\n\u003ctd\u003eATtiny841 (\u003ca href=\"http:\/\/www.uugear.com\/doc\/datasheet\/ATtiny841.pdf\" target=\"_blank\" rel=\"noopener noreferrer\"\u003edatasheet\u003c\/a\u003e)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRealtime Clock\u003c\/td\u003e\n\u003ctd\u003ePCF85063A (\u003ca href=\"https:\/\/www.uugear.com\/doc\/datasheet\/PCF85063A.pdf\" target=\"_blank\" rel=\"noopener noreferrer\"\u003edatasheet\u003c\/a\u003e), calibrated in factory.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Sensor\u003c\/td\u003e\n\u003ctd\u003eLM75B (\u003ca href=\"https:\/\/www.uugear.com\/doc\/datasheet\/LM75B.pdf\" target=\"_blank\" rel=\"noopener noreferrer\"\u003edatasheet\u003c\/a\u003e)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMOSFET Switch\u003c\/td\u003e\n\u003ctd\u003eAO4620 (\u003ca href=\"https:\/\/www.uugear.com\/doc\/datasheet\/AO4620.pdf\" target=\"_blank\" rel=\"noopener noreferrer\"\u003edatasheet\u003c\/a\u003e)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSuper Capacitor\u003c\/td\u003e\n\u003ctd\u003e0.07F\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower In\u003c\/td\u003e\n\u003ctd\u003eDC 5V (via USB type C connector) or 5V in unpopulated header P2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOutput Current\u003c\/td\u003e\n\u003ctd\u003eUp to 2.5A for Raspberry Pi and its peripherals\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eStandby Current\u003c\/td\u003e\n\u003ctd\u003e~0.5mA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd rowspan=\"2\"\u003eOperating Environment Temperature\u003c\/td\u003e\n\u003ctd\u003e-30°C~80°C (-22°F~176°F)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHumidity 0~80%RH, no condensing, no corrosive gas\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch2\u003eUSER MANUAL\u003c\/h2\u003e\n\u003cp\u003eMore information about this product can be found in its \u003ca href=\"https:\/\/www.uugear.com\/doc\/WittyPi4Mini_UserManual.pdf\" target=\"_blank\"\u003euser manual\u003c\/a\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003ch2\u003eSCHEDULE SCRIPT GENERATOR\u003c\/h2\u003e\n\u003cp\u003eYou can now use \u003ca href=\"http:\/\/www.uugear.com\/app\/wittypi-scriptgen\/\" target=\"_blank\" rel=\"noopener noreferrer\"\u003ethis web app\u003c\/a\u003e to create and debug the schedule script for Witty Pi.\u003c\/p\u003e","brand":"UUGear","offers":[{"title":"Default Title","offer_id":40171303403603,"sku":"WITTY_PI_4_MINI","price":20.95,"currency_code":"EUR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0174\/1800\/products\/04-1.jpg?v=1660136087","url":"https:\/\/shop.pimoroni.com\/en-eu\/products\/witty-pi-4-mini-realtime-clock-and-power-management-for-raspberry-pi","provider":"Pimoroni Ltd","version":"1.0","type":"link"}