pxt-calliope/docs/about.md
2016-03-28 23:18:27 -07:00

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About

The BBC micro:bit is a pocket-size computer with a 5x5 display of 25 LEDs, Bluetooth and sensors that can be programmed by anyone. The BBC micro:bit was made possible by many partners.

The micro:bit provides a fun introduction to programming and making switch on, program it to do something fun wear it, customize it. Just like Arduino, the micro:bit can be connected to and interact with sensors, displays, and other devices.

Blocks or JavaScript

The student can program the BBC micro:bit using visual blocks or JavaScript.

basic.showString("BBC micro:bit!");

Compile and Flash

When a user has her code ready, she can connect her BBC micro:bit to a computer via a USB cable, so it appears as a mounted drive.

Compilation to the ARM thumb machine code happens in the browser.

The student is prompted to save the ARM binary program to a file, which she then simply drags to the micro:bit mounted drive, which flashes the micro:bit device with the new program.

Simulator: Test Your Code

Before a student compiles her code for the micro:bit, she can run it using the micro:bit simulator, all within the confines of a web browser. The simulator has support for the LED screen, buttons, as well as compass, accelerometer, and digital I/O pins.

input.onButtonPressed(Button.A, () => {
    basic.showLeds(`
. . . . .
. # . # .
. . . . .
# . . . #
. # # # .`);
});
input.onGesture(Gesture.Shake, () => {
    basic.showLeds(`
. . . . .
. # . # .
. . . . .
. # # # .
# . . . #`);
});

C++ Runtime

The C++ BBC micro:bit library, created at Lancaster University, provides access to the hardware functions of the micro:bit, as well as a set of helper functions (such as displaying a number/image/string on the LED screen). The JavaScript micro:bit library mirrors the functions of the C++ library. When code is compiled to ARM machine code, the calls to JavaScript micro:bit functions are replaced with calls to the corresponding C++ functions.