Mazduino ECU Custom Firmware

Custom rusEFI firmware for Mazduino ECU boards and compatible STM32F4-based engine management systems.

Download

Pre-built firmware is published as nightly releases on the Releases page.

Each release includes .bin, .srec, and .hex files for every supported board.

TunerStudio INI files

Every published firmware's TunerStudio INI is kept at mazduino.github.io/mazduino-fw, grouped by board with the newest first. Use it when a release bundle is gone, or when TunerStudio reports that the firmware signature does not match the project.

INI files are stored by firmware signature. A signature such as rusEFI master.2026.09.08.mazduino-lite.969326114 (branch, build date, board, config hash) maps to:

https://mazduino.github.io/mazduino-fw/ini/master/2026/09/08/mazduino-lite/969326114.ini

The hash must match the firmware exactly: it identifies the config layout, so an INI with another hash reads and writes settings at the wrong offsets. The files are published by the nightly release workflow (nightly-release.yaml) to the gh-pages branch.

Supported Boards

Features per board lists what each firmware has. It is generated from the board definitions, so it stays correct when they change.

Mazduino Compact

• MCU: STM32F407VGT6 (1MB flash)
• Hardware knock detection via ADC3/PA3
• Software knock spectrogram
• CAN bus, USB virtual COM port (TunerStudio)
• Dual idle solenoid outputs
• No ETB, no traction control

Mazduino Lite

• MCU: STM32F407VGT6 (1MB flash)
• No hardware knock (ADC3 not connected)
• CAN bus, USB virtual COM port
• Dual idle solenoid outputs
• No ETB, no traction control

Mazduino Mini 6CH (STM32F407VGT6 or STM32F427VGT6)

• MCU: STM32F407VGT6 on earlier boards, STM32F427VGT6 on current ones (1MB flash). One firmware runs on both
• Secondary TunerStudio channel for a Bluetooth module (PB10/PB11)
• Electronic throttle body (ETB) support
• Traction control (requires ETB)
• Hardware knock detection
• CAN bus, USB virtual COM port

Mazduino Core (STM32F427ZGT6)

• MCU: STM32F427ZGT6, LQFP144 (1MB flash) — not the 100-pin VGT6 used by the rest of the fleet; GPIOF/G are only bonded out on the 144-pin package, and this pinout needs them
• 6 injector outputs (3A), 6 ignition outputs, 4 extra low-side outputs (3A), 2 high-side outputs (1.3A), 5 auxiliary/relay outputs
• Dual electronic throttle (ETB), stepper idle (dual H-bridge), onboard LPS25 baro sensor
• 11 analog inputs (7 voltage + 4 temperature), 4 digital inputs
• CAN bus + CAN2 (jumper), SD card logging, USB virtual COM port and real TunerStudio port selector
• TunerStudio over Bluetooth on the TunerStudio serial port (PD5/PD6)
• In firmware the brain board uses the official rusEFI Proteus F4 pinout (12 low-side + 4 high-side outputs, 12 ignition outputs); the list above is what the 48-pin carrier connector brings out
• No knock input on the connector: Core is a brain board on a carrier board, and the 48-pin carrier does not bring knock out. The firmware still supports it, on PF4/PF5 (ADC3) of the brain board, off by default
• Traction control (requires ETB)

Mazduino Mega100 (STM32F407VGT6)

• MCU: STM32F407VGT6 (1MB flash)
• Full feature set: ETB, traction control, knock, boost, launch control
• Dual pinout support: board04 layout and UA4C layout, switchable via TunerStudio board action
• USB virtual COM port and CAN bus for TunerStudio connection
• Status LED at PB7

Mazduino Mega100-512 (STM32F407VET6)

• MCU: STM32F407VET6 (512KB flash)
• Firmware constrained to 384KB to preserve tune storage sector
• Feature reduction vs Mega100: see Features per board
• CAN bus or USB virtual COM port for TunerStudio connection
• Status LED at PB7

BIGFUEL variants

mazduino-compact-bigfuel, mazduino-core-bigfuel, mazduino-lite-bigfuel and mazduino-mini6ch-bigfuel are the same hardware as the board they are named after, with 32x32 VE and ignition tables. Tunes are not interchangeable between a board and its BIGFUEL variant.

TunerStudio Connection

Board	Connection
Compact, Lite, Mini 6CH, Core	USB virtual COM port
Mega100	USB virtual COM port or CAN bus
Mega100-512	USB virtual COM port or CAN bus

Building Firmware

Local Build (Docker)

Docker is required. The build image uses Ubuntu Mantic with ARM GCC toolchain.

# Build all boards
./build_boards.sh

# Build a single board
./build_boards.sh mazduino-compact

The script uses --platform linux/amd64 to ensure hex2dfu.bin (x86-64) runs correctly on Apple Silicon via Rosetta 2.

CI Build (GitHub Actions)

All boards are built automatically on every push via the matrix workflow in .github/workflows/build-matrix.yaml. Nightly releases are published by .github/workflows/nightly-release.yaml.

Flash Instructions

ST-Link or SWD

Use STM32CubeProgrammer or OpenOCD with the .bin file:

st-flash write rusefi_mazduino-compact.bin 0x08000000

DFU (USB bootloader)

Put the board into DFU mode (hold BOOT0 while resetting), then:

dfu-util -d 0483:df11 -a 0 -s 0x08000000:leave -D rusefi_mazduino-compact.bin

OpenBLT Bootloader

Use the .srec file with the rusEFI Flasher tool or BootCommander.

Repository Structure

boards/
  mazduino-compact/       # Board-specific configuration files
  mazduino-lite/
  mazduino-mini6ch/
  mazduino-core/
  mazduino-mega100/
  mazduino-mega100-512/
ext/rusefi/               # rusEFI submodule
generated/                # Auto-generated code (configs, headers, INI files)
.github/workflows/        # CI/CD workflows

Each board directory contains:

• meta-info.env - Board identity and CPU selection
• board.mk - Makefile flags and feature overrides
• board_configuration.cpp - Pin assignments and hardware init
• efifeatures.h (optional) - Feature flag overrides
• prepend.txt - TunerStudio UI visibility flags
• knock_config.h - Knock sensor configuration

Safety Notice

This is engine management software controlling critical engine functions. Test on a bench setup before installing in a vehicle. Incorrect configuration can cause engine damage.

Links

• rusEFI Project
• rusEFI Custom Firmware Guide
• Mazduino Wiki