TinyGo — Go Compiler for Microcontrollers and WebAssembly

Introduction

TinyGo is an alternative Go compiler that produces much smaller binaries than the standard Go toolchain. It targets microcontrollers, WebAssembly, and constrained environments where the full Go runtime is too large, while keeping compatibility with standard Go syntax and most of the standard library.

What TinyGo Does

• Compiles Go programs for 90+ microcontroller boards (Arduino, ESP32, STM32, nRF)
• Produces WebAssembly binaries far smaller than standard Go's Wasm output
• Supports hardware peripherals like GPIO, I2C, SPI, ADC, and UART
• Integrates with the Go module system and standard library (partial support)
• Provides a machine package for direct hardware register access

Architecture Overview

TinyGo uses LLVM as its compilation backend instead of Go's native backend. It performs whole-program optimization, dead code elimination, and aggressive inlining to produce small binaries. The runtime is reimplemented with a lightweight scheduler (cooperative or preemptive depending on target), a simple GC suited for constrained memory, and thin HAL layers per chip family.

Self-Hosting & Configuration

• Install as a single binary alongside a standard Go installation
• Target selection via -target flag (arduino-nano, esp32, wasm, wasi, etc.)
• Board definitions stored as JSON files describing pins and peripherals
• Supports OpenOCD and J-Link for debugging on hardware
• Environment variable TINYGOROOT for custom board definitions

Key Features

• Binary sizes as small as a few KB for microcontroller targets
• 90+ supported boards out of the box with community additions
• Bluetooth Low Energy support via the bluetooth package
• WebAssembly output 10-50x smaller than standard Go compiler
• Concurrent goroutines on microcontrollers with minimal overhead

Comparison with Similar Tools

• Standard Go — Full runtime is too large for MCUs; TinyGo fits in kilobytes
• Rust embedded — More mature embedded ecosystem; TinyGo offers Go's simpler syntax
• MicroPython — Interpreted and slower; TinyGo compiles to native code
• Arduino C++ — TinyGo provides memory safety and goroutines for concurrency
• CircuitPython — Beginner-friendly but limited; TinyGo scales to complex applications

FAQ

Q: Does TinyGo support all Go packages? A: Most standard library packages work. Some (like net/http or os/exec) are unavailable on bare-metal targets due to missing OS features.

Q: Can I use goroutines on microcontrollers? A: Yes. TinyGo includes a lightweight scheduler that runs goroutines cooperatively with very low RAM overhead.

Q: How do I debug on hardware? A: TinyGo integrates with GDB via OpenOCD or J-Link. Use tinygo gdb to start a debug session.

Q: What is the minimum RAM for a TinyGo program? A: Simple programs can run in as little as 2KB RAM on cortex-m0 targets.

Sources

• https://github.com/tinygo-org/tinygo
• https://tinygo.org/docs/