Frequently Asked Questions

Where can we buy the board?
You can buy the Calliope mini at several resellers or here directly: Get your Calliope mini!

Can I help with bringing the Calliope mini to my country?
We would be happy to bring Calliope mini to every country! If you are interested in partnering, please write us an e-mail:

Where do I find teaching material?
Of course! Different providers are working on material, from online tutorials to printed books and classroom boxes. Material is the linchpin of the whole project, that's why we're preparing this material thoroughly with different partners, for example with the German educational provider Cornelsen. We feel close to the idea of open educational resources (OER), that's why we encourage our partners to provide OER material and make it applicable on our website. The first teaching material can be downloaded on our page for teachers here (German only).

Why not Arduino or Raspberry Pi?
The Raspberry is too complex for primary school, same applies to the Arduino. Both need extra shields or hats (sensors, speakers) to be useful in class. This doesn't make sense in regular schools. That's why we wanted to build an affordable board with all the features needed for a wide variety of experiments.

Why shouldn't we choose the British micro:bit?
There are two reasons for not doing so: The contact strip is arranged in a way that leads to short circuits quite regularly - the contacts are too close to each other (that's also why we chose the star shape for the mini, putting the contacts as far away from each other as possible). Furthermore, the micro:bit lacks a few important components, to supply students with great experiments, most importantly a speaker, a RGB-LED and a microphone.
We place great emphasis on a maximum of compatibility to the British model - that's why it's possible to use existing code for the micro:bit on the mini as well.

What does "Calliope" mean?
Calliope was the daughter of Zeus and is seen as a "tablet muse" by many computer scientists, thus, an early precursor for digital education ideals. Just look up "Calliope" and take a look at the pictures.

How is the Calliope gGmbH funded?
Our company is a non-profit Ltd. Our money comes from three sources: Firstly, the founders put in their share capital according to the statute. After being funded by the Federal Ministry of Economics and Technology and a smaller funding contract for the IT summit we exclusively asked for donations - all donors are mentioned on the partners page. Donors (officially grant authorities) can either donate money or, in special cases, hardware or personal contributions like components for the board or training measures. Monetary donations of sponsors are bound to the purchase of Calliope mini boards for students or completely free from a specified purpose. Some donors want a connection with other training initiatives related to our project, like Google with Fraunhofer-Roberta or Microsoft with "Code your Life". We are also happy about support from other NGOs like the App Camps in Hamburg or KiWiZ in Hannover. Our only return for the donors is that they are mentioned as supporters of the project, they do not have any influence on the work of Calliope gGmbH. The third source will be the commercial sale of the Calliope mini. All revenues will eventually flow back into funding our company targets, so more boards and material for kids are bought with this.

Technical questions

What processor are you using?
We are using the Nordic NRF51822, a ARM Cortex M0 32bit processor with 16kb RAM and 256kb Flash memory. We also added the NXP MKL26Z as an interface processor for the USB port, it also lets you program the board via Browser.

What protocols does the board support?
Both grove connectors offer one I2C and one UART. Using the 26-pin GPIO you can also use SPI.

What kind of extensions work with the mini?
There are a lot of Grove connectors that can be used easily by attaching them to one of the two ports.

What motor driver is used?
It's the DRV8837 by Texas Instruments. It's a so-called H-Bridge you can connect two DC motors to which can be regulated in one direction. If you only connect one motor, you can go forwards and backwards.

What acceleration/position sensor is used?
It's the BMX055 by Bosch.

Is there a possibility to program the board with something else than the block editor?
Yes, you can control it via mbed as well. Furthermore, it's possible to use MicroPython. You can find the current build environment here.

Is the mini only made for use in schools?
Shape and concept is optimized for the use in schools, but the mini can be used in various ways. The open source system RIOT was adjusted (more info here) and can be installed on the mini. Furthermore, there are first approaches and first use cases by developers to use the mini in completely different ways.

How can I support you with your development?
There's many ways to help us. The easiest way is to get into contact with us. Technically skilled users can use the GitHub repository with information on the mini. You can help us make the mini even better!

First Aid

Where can I find a manual for the intro script?
You can find a description for the demo scripts delivered with the mini here.

How can I reinstall the demo program on my mini?
If the logo is on the left side of the board, you can find the original file here. After the download you can put it on the Calliope mini like any self-made script.

Why doesn't the editor work with my mini?
There's two different versions of the editor, the latest boards work with the latest version of the editor. If the Calliope mini logo is on the right side of the LED grid 6 (close to button B), please use this version: If it's on the left side, use this version:

How can I use Bluetooth to flash the board?
The mini can be flashed via Bluetooth from any smartphone or tablet - like the micro:bit. Currently there is an iOS app available only, but we are working on an Android version, too.

What can I do when my mini isn't recognized as a USB drive?
In this case the main firmware on the mini has to be re-transferred. Keep the reset button pressed when connecting the USB cable. The mini should show up as "MAINTENANCE". You can transfer the firmware to this drive, the firmware can be found here.