JARU Blog

JARU 0.9.7 is out. If 0.9.6 was the release of the physics engine and sound, this one is about making games faster and having them run better on the board: there is a scene editor to lay out rooms without writing the code by hand, the interpreter is noticeably faster and uses less memory on the ESP32, and the IDE gets a new look and a new sprite editor.

Before rebuilding your projects, read the breaking changes section: you need to flash the new firmware on your boards, and a few behaviour changes may require touching code.

The JARU IDE Music Tracker lets you compose your game's music without leaving the environment, just like code or sprites. This tutorial walks through the whole process with screenshots: start from a template, type notes into the grid, tweak an instrument, listen to the result, and leave it ready for your program to play.

JARU 0.9.6 is out, and it is by far the biggest step the project has taken so far. This is not a round of touch-ups: there is a new physics engine written from scratch, a sound and music system that simply did not exist before, a new virtual machine for the ESP32-P4, and two additions to the language itself.

If you are coming from 0.9.5, it is worth reading the breaking changes section before you rebuild your projects: there are only a few, but three of them may require touching code.

Developing for microcontrollers can be very rewarding, but it can also involve a lot of friction: configuring tools, connecting hardware, checking serial ports, flashing again and again, checking wires, adding debug messages, and repeating the cycle until the problem finally appears.

JARU IDE was created to reduce the distance between an idea and a first working version.

It is not meant to replace every existing tool or become the only way to program an ESP32. Its value is elsewhere: it offers a fast, visual, integrated environment for building prototypes, preparing proofs of concept, and teaching programming with fewer early obstacles.

One of the features I am adding to JARU IDE is an integrated Music Tracker. I wanted music to be part of the project itself, not something external: a resource that can be created, edited, tested, and compiled from the IDE, just like code, images, or sprites.

The idea is simple: users should be able to compose a chiptune melody, import a MIDI file, adapt retro-style game music, and then use it in presentations, demos, games, or interactive applications made with JARU.

This tutorial focuses on the graphical side of JARU: opening a screen, preparing a drawing surface, and building a small interface with the Display and Draw modules: text, cards, status bars, rectangles and circles.

The first step in the hardware world is always to blink an LED. In this tutorial you will learn the basic syntax of JARU and discover one of its best features: write the code once and test it both in the Windows simulator and on your physical ESP32 board.

After blinking an LED, the next natural step is reading the outside world. In this tutorial you will learn how to connect a push button, read its state with GPIO.read, and finally react to presses using interrupts — all tested first in the Windows simulator and then on your physical ESP32.