Real-Time Clock Bricklet


The Real-Time Clock Bricklet is discontinued. We are selling our remaining stock. The Real-Time Clock Bricklet 2.0 is the recommended replacement.


  • Battery-backed real-time clock
  • Hundredth of a second time resolution
  • Low power consumption in battery mode


The battery-backed Real-Time Clock Bricklet can be used to extend the features of Bricks with the capability to accurately keep date and time over long time periods even if the Brick is not constantly powered.

This Bricklet can also be used to keep the system time of a RED Brick (using this example program) or a Raspberry Pi.

Technical Specifications

Property Value
Sensor PCF85263A
Current Consumption
< 5mW (< 1mA at 5V)
1.05µW (680nA at 1.55V) im battery mode*
Date Format 2000-01-01 to 2099-12-31 including weekday and leap years
Time Format 24h with hundredths of a second
±20ppm (±52.6 seconds per month) non-calibrated
down to ±1ppm (±2.6 seconds per month) calibrated*
Battery Type SR621SW / 364 / SR60 / S621 / SG1 or LR60 / L621 / AG1
Battery Dimensions 6.8 x 2.2mm (0.27 x 0.09")
Dimensions (W x D x H) 25 x 25 x 5mm (0.98 x 0.98 x 0.19")
Weight 3g

* datasheet value


Test your Real-Time Clock Bricklet

To test a Real-Time Clock Bricklet you need to have Brick Daemon and Brick Viewer installed. Brick Daemon acts as a proxy between the USB interface of the Bricks and the API bindings. Brick Viewer connects to Brick Daemon. It helps to figure out basic information about the connected Bricks and Bricklets and allows to test them.

Connect the Real-Time Clock Bricklet to a Brick with a Bricklet Cable.

If you connect the Brick to the PC over USB, you should see a new tab named "Real-Time Clock Bricklet" in the Brick Viewer after a moment. Select this tab. If everything went as expected you can now see the Bricklet's and the local date and time counting up.

You can set the Bricklet's date and time you your local time by clicking the "Save Local" button.

Real-Time Clock Bricklet in Brick Viewer

After this test you can go on with writing your own application. See the Programming Interface section for the API of the Real-Time Clock Bricklet and examples in different programming languages.


A laser-cut case for the Real-Time Clock Bricklet is available.

Case for Real-Time Clock Bricklet

The assembly is easiest if you follow the following steps:

  • Screw spacers to the Bricklet,
  • screw bottom plate to bottom spacers,
  • build up side plates,
  • plug side plates into bottom plate and
  • screw top plate to top spacers.

Below you can see an exploded assembly drawing of the Real-Time Clock Bricklet case:

Exploded assembly drawing for Real-Time Clock Bricklet

Hint: There is a protective film on both sides of the plates, you have to remove it before assembly.

Programming Interface

See Programming Interface for a detailed description.

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