This repository contains the source code for MicroBlocks. To learn more about MicroBlocks and how to use it please visit the MicroBlocks website, http://microblocks.fun
MicroBlocks is a free, live, blocks programming system for educators, learners, and makers that its creaters hope will become "the Scratch of physical computing." It runs on the BBC micro:bit, Calliope mini, AdaFruit CircuitPlaygraound Express, NodeMCU, ESP32, many ARM-based Arudino boards, and other tiny computers such as the Raspberry Pi.
The MicroBlock firmware (or virtual machine) runs on 32-bit embedded processors with as little as 16k of RAM. It is intended to be simple, easily ported and extended, and offer decent performance. It includes a low-latency task scheduler that works at timescales down to about 30 microseconds. It will eventually include a garbage collected memory to allow working with dynamic data structures -- within the limits of the available RAM, of course!
MicroBlocks supports both live development and autonomous operation. Live development allows the user to see the results of program changes immediately, without the overhead of compiling and downloading. Autonomous operation means that programs continue to run when the board is untethered from the host computer. Because MicroBlocks programs run directly on the microcontroller -- in contrast to tethered systems where the program runs on a laptop and uses the microcontroller as an I/O device -- programs can work precisely at timescales down to 10's of microseconds. For example, MicroBlocks can generate musical tones and servo waveforms and it can analyze incoming signals such as those from an infrared remote control.
Finally, since MicroBlocks stores the user's program in persistent Flash memory, MicroBlocks will eventually allow the user's program stored on the board to be read back into a MicroBlocks development environment for inspection and further development.
MicroBlocks supports user-defined blocks (commands and functions). That mechanism is used to create MicroBlocks libraries, so advanced users can explore the implementation of libraries learn how they work or even extend them.
Built-in data types include integers, booleans, strings, and lists.
First of all, you may not need to. The firmware for many boards, including the BBC micro:bit, Calliope mini, AdaFruit Circuit Playground Express, Citilab ED1, M5Stack, NodeMCU, and ESP32 Dev board is can be installed using the "update firmware on board" menu command in the interactive development environment (IDE).
However, if you have one of the other supported boards, or if you just want to build the firmware yourself, read on.
The MicroBlocks firmware, also called the virtual machine, is written in C and C++. It is built on the Arduino platform and uses additional Arduino libraries for features such as graphics and WiFi (on boards that support those features).
The source code repository is here. To get the source code, you can either clone it:
git clone https://john_maloney@bitbucket.org/john_maloney/smallvm.git
or download a snapshot of it by selecting "download repository" from the "..." menu to the right of the "Clone" button on the repository home page.
PlatformIO is the preferred build tool. PlatformIO is a cross platform build system that is easy to install an use. It's only dependency is Python, which comes pre-installed on MacOS and Linux and is easy to install on Windows. You can get the PlatformIO command line interface (CLI) tools here.
To compile the firmware for all platforms, just enter the "smallvm" folder and run:
pio run
To compile and install the VM for a particular board (e.g. the BBC micro:bit), plug in the board and run:
pio run -e microbit -t upload
The MicroBlocks virtual machine can also be compiled and loaded onto a board using the Arduino IDE (version 1.8 or later) with the appropriate board package and libraries installed.
To build with the Arduino IDE, open the file vm.ino, select your board from the boards manager, then click the upload button.
To build the VM on the Raspberry Pi, run "./build" in the raspberryPi folder. The Raspberry Pi version of MicroBlocks can control the digital I/O pins of the Raspberry Pi.
On the Raspberry Pi, MicroBlocks can be run in two ways:
Desktop: If you run ublocks-pi with the "-p" switch, it will create a pseudoterminal, and you can connect to that pseudoterminal from the MicroBlocks IDE running in a window on the same Raspberry Pi.
Headless: If you configure your RaspberryPi Zero(W) to behave like a slave USB-serial device, then it can be plugged into a laptop as if it were an Arduino or micro:bit. The MicroBlocks VM can be started on a headless Pi either by connecting to the Pi via SSH and running ublocks-pi from the command line or by configuring Linux to start the VM at boot time.
To build the VM to run on a generic Linux computer, run "./build" in the linux folder. Running the resulting executable creates a pseudoterminal that you can connect to from the MicroBlocks IDE running on the same computer.
The generic Linux version of the VM can't control pins or other microcontroller I/O devices (there aren't any!), but it can be used to study the virtual machine. It's also handy for debugging, since the Linux VM can print debugging information to stdout without interfering with the VM-IDE communications (which goes over the pseudoterminal connection).
The MicroBlocks IDE is written in GP Blocks. You'd find source code for the IDE is in the ide and the gp libraries and build scripts in the the gp folder.
Although MicroBlocks is currently "alpha", it is stable and has been used by hundreds of people, many of them complete beginners. The "alpha" status is because MicroBlocks is still evolving. If you are writing documentation, you should to update it to track changes to the libraries, blocks, and UI.
We hope to enter "beta" by early 2020.
We welcome your feedback, comments, feature requests, and bug reports.
Since MicroBlocks is still under active development by the core team, we are not currently soliciting code contributions or pull requests. However, if you are creating tutorials or other materials for MicroBlocks, please let us know so we can link to your website.
This project is a collaboration between John Maloney, Bernat Romagosa, and Jens Moenig, with input and help from many others. It is under the fiscal sponsorship of the Software Freedom Conservancy, a 501(c)(3) non-profit.
MicroBlocks is licensed under the Mozilla Public License 2.0 (MPL 2.0).