Modules

Modules are the part of JARU that talks to the world: the screen, the sound, the buttons, the board's pins, the network and the files. Each one gathers its functions, properties and constants under a name, which you write in front: Display.open, GPIO.write, Math.PI.

How to use them

A program says which modules it uses with use, one per line or several separated by commas:

use Math, GPIO
use Display

println(Math.sqrt(16))   // 4

• A name that isn't a module doesn't compile: use Nothing gives the error Module not found.
• If you use a module without its use, the program compiles, but stops when it reaches that line with ERR_MODULE_NOT_FOUND (Module 'Math' not found or not imported.).
• use is for JARU's modules; your project's files are brought in with import. The difference is in Programs in several files.

The modules are the same on Windows and on every board. What changes from one platform to another is told by each page in its "Platforms" section.

Some functions don't belong to any module and need no use, such as println, pause, clock or random: they're in the Standard library. The methods of strings, lists and maps are in Strings and in Lists, maps and arrays.

The modules

Graphics and games

Module	What for
Display	Opening the screen or the window, its size and its background, and the game's pace
Draw	Drawing points, lines, rectangles, circles, text, images and tilemaps
Bitmap	Loading BMP images and working with them
Sprite	Sprites with animation, collisions and physics
GridMap	2D grids: tilemaps, collisions with the map and pathfinding
Scene	The scene: its sprites, the camera, the physics and the map
Sound	Synthesised sounds, PCM samples and music

Input

Module	What for
Input	The keyboard, the buttons and the gamepad, as game actions

Hardware

Module	What for
GPIO	Input and output pins, PWM and interrupts
I2C	Sensors and other devices connected over I2C
LED	Strips and matrices of WS2812 colour LEDs
Power	Putting the board to sleep to save power, and waking it up

Communications

Module	What for
MQTT	Publishing and receiving MQTT messages
Http	HTTP requests to APIs and web services

Data and files

Module	What for
File	Files and folders, in the flash, on the SD card or on the PC
Bytes	Byte blocks for binary data
JSON	Reading and writing JSON

System

Module	What for
Timer	Calling a function after some time, once or every so often
Math	Mathematical functions and constants
GC	The garbage collector, which frees the memory that's no longer used