Elmwood no more, long live Elmwood! Elmwood Electronics and PiShop are now together!
Please order via PiShop.ca, as we are no longer taking orders through this site.
More details are in our blog!

Witty Pi 3 Mini: Realtime Clock and Power Management for Raspberry Pi

C1421

Elmwood Electronics has stopped accepting orders. This product might be available at PiShop.ca. Please check this blog post about our recent team merger.

Witty Pi 3 Mini adds RTC (DS3231SN) and power management to your Raspberry Pi, and can define complex ON/OFF sequence with a simple script.

PRODUCT DESCRIPTION

Witty Pi is small electronic circuit board that can add realtime clock and power management to your Raspberry Pi. Witty Pi 3 Mini is a new member of the third generation of Witty Pi, and it has pHAT shape (Raspberry Pi Zero size).

After installing Witty Pi 3 Mini on your Raspberry Pi, you get some amazing new features:

  • You can gracefully turn on/off Raspberry Pi with single tap on the switch.
  • After shutdown, Raspberry Pi and all its USB peripherals’ power are fully cut.
  • Raspberry Pi knows the correct time, even without accessing the Internet.
  • Raspberry Pi knows the temperature thanks to the sensor in RTC chip.
  • You can schedule the startup/shutdown of your Raspberry Pi.
  • You can even write a script to define complex ON/OFF sequence.
  • Monitor external voltage and turn on/off your Raspberry Pi accordingly.

Witty Pi 3 Mini supports all Raspberry Pi models that has the 40-pin GPIO header, including A+, B+, 2B, Zero, Zero W, 3B, 3B+, 3A+ and 4B.

Witty Pi 3 Mini uses the same software with Witty Pi 3. You just need to run these two commands in your Raspberry Pi to install the software:

1
2
3
pi@raspberrypi:~ $ wget http://www.uugear.com/repo/WittyPi3/install.sh
 
pi@raspberrypi:~ $ sudo sh install.sh

 

Comparing to Witty Pi 3, Witty Pi 3 Mini uses the same RTC chip (DS3231SN) and same micro-controller (ATtiny841). The main difference is the LDO voltage regulator (LM29150) is not populated on Witty Pi 3 Mini. This reduces the cost for those who don’t need this LDO, and also make things easier to integrate a different DC/DC module into Witty Pi 3 Mini.

Unlike Witty Pi 3 uses a 3V button battery for off-power time keeping, Witty Pi 3 Mini uses a super capacitor (0.08F, or 80000uF) for this purpose.

You can find more information in its user manual: http://www.uugear.com/doc/WittyPi3Mini_UserManual.pdf

PACKAGE CONTENT:

Each Witty Pi 3 Mini package contains:

  • Witty Pi 3 Mini board x 1
  • M2.5 x 10mm plastic screw x 4
  • 4mm spacer x 4
  • M2.5 plastic nut x 4

Dimension:

65mm x 30mm x 4mm

Weight

8g (net weight)

Micro Controller

ATtiny841(datasheet)

Realtime Clock

DS3231SN (datasheet)

LED Indicator

Red LED: lights up when Raspberry Pi gets powered.

White LED: lights up for a few seconds when a shutdown command is received, or blinks when device is standing by.

Connector

20×2 surface-mounted header with 2.54 mm pitch and 2mm plastic height.

Micro USB female connector as 5V DC input.

Unpopulated 7-pin header for extension or integration.

Unpopulated 3-pin header/connector for VIN, GND and 5V.

Time Keeping

Using 0.08F super capacitor as time keeping power source. Allows about 17 hours off-power time keeping.

Power In

DC 5V (via micro USB). Possible to connect external DC/DC converter (not included) and also have VIN monitored.

Output Current

Up to 2.5A for Raspberry Pi and its peripherals. If using external DC/DC converter, the output current is also limited by the capability of DC/DC converter.

Standby Current

~ 1mA

Operating Temperature

-30~80 (-22F~176F)

Storage Temperature

-40~85 (-40F~185F)

Humidity

0~80%RH, no condensing

Collections: Raspberry Pi

Type: Raspberry Pi > Clock