Getting Started

Mon, 01 Jan 0001 00:00:00 +0000

is a lightweight font rendering library designed for microcontrollers. It works with any display that implements the drivers.Displayer interface — OLEDs, TFT screens, e-ink panels — and draws text one pixel at a time, making it ideal for resource-constrained environments where a full font engine would be too large.

Quick start

import (
 "image/color"
 "tinygo.org/x/tinyfont"
)

// disp is any drivers.Displayer (e.g. an SSD1306 OLED or ILI9341 TFT)
tinyfont.WriteLine(disp, &tinyfont.TomThumb, 2, 14, "Hello!", color.RGBA{R: 0xff, A: 0xff})

WriteLine signature:

func WriteLine(display drivers.Displayer, font Fonter, x, y int16, str string, c color.RGBA)

Parameter	Description
`display`	Target display — anything with `SetPixel` + `Size`
`font`	A `Fonter` value — pointer to one of the font variables
`x`, `y`	Top-left origin of the text baseline (pixels)
`str`	The string to render (ASCII; full Unicode depends on font)
`c`	Foreground color as `color.RGBA`

Built-in fonts

The root package ships four bitmap fonts that range from tiny to small:

Variable	Size	Best for
`tinyfont.Tiny3x3a2pt7b`	3×3 px	Status indicators, tiny labels
`tinyfont.Picopixel`	~5 px	Dense data on small OLEDs
`tinyfont.TomThumb`	~6 px	Compact, very readable at small sizes
`tinyfont.Org01`	~6 px	Clean monospace look

Sub-packages (freemono, freesans, freeserif, notosans, proggy, gophers) add larger proportional and monospace faces at the cost of binary size.

API Reference & Examples

Mon, 01 Jan 0001 00:00:00 +0000

The `drivers.Displayer` interface

type Displayer interface {
 // SetPixel draws a single pixel at (x, y) with color c.
 SetPixel(x, y int16, c color.RGBA)

 // Size returns the display dimensions in pixels.
 Size() (x, y int16)

 // Display flushes buffered data to the hardware (no-op for direct-write displays).
 Display() error
}

Any struct that satisfies these three methods can be passed to tinyfont.WriteLine. The TinyGo drivers package provides ready-made implementations for most common displays.

Multi-line text

For displays with limited height, you can call WriteLine multiple times advancing y by the font’s line height:

lineH := int16(10)
y := lineH
for _, line := range strings.Split(text, "\n") {
 tinyfont.WriteLine(disp, &tinyfont.TomThumb, 2, y, line, white)
 y += lineH
}

Font tester

Try out the built-in fonts directly in the browser. The widget below runs the same rendering code you would use on a real microcontroller, compiled with TinyGo to WebAssembly.

Loading WASM…

Text

Font

Foreground

Background

Display

Scale

⚠️ WASM binary not found. Run ./build-wasm.sh to build it.

Select a font, adjust colors, choose a display size, and type your text to preview exactly how it will look on the target hardware.

Tinyfont | Go Education Project