Documentation

Overview

The Digispark is a thumbnail-sized development board built around the ATtiny85 microcontroller. It plugs directly into a USB port — no cable, no separate programmer — and is programmed from the Arduino IDE through the Digistump board package. With six I/O pins and about 6 KB of usable flash, it is not a replacement for an UNO; it is the board you reach for when a full Arduino is overkill.

Typical uses: a single-sensor trigger, an LED controller, a small automation gadget, a wearable, or a simple USB keyboard emulator. Its tiny footprint and sub-dollar-chip economics make it easy to leave permanently embedded in a finished project.

Uploading works differently than on other Arduinos — you plug the board in after clicking Upload. The Getting Started section below walks through it.

At a Glance

Specifications

Getting Started

The Digispark needs no wiring — it plugs straight into a USB-A port. What it does need is a one-time IDE setup and a different upload rhythm than other Arduinos.

1. Install the Digistump board package

In the Arduino IDE, open File → Preferences and add the Digistump package URL to "Additional Boards Manager URLs": http://digistump.com/package_digistump_index.json. Then install "Digistump AVR Boards" from the Boards Manager and select Digispark (Default - 16.5mhz). On Windows, install the Digistump/micronucleus drivers if the board is not recognized.

2. The upload ritual

Click Upload with the board unplugged. When the console prints "Plug in device now...", insert the Digispark into USB. The micronucleus bootloader runs for the first ~5 seconds after plug-in, accepts the sketch, then starts it automatically.

Code Examples

Blink (first upload test)

// Digispark ATtiny85 - Blink the onboard LED
// LED is on P1 (change to 0 if your revision uses P0)

const int LED_PIN = 1;

void setup() {
  pinMode(LED_PIN, OUTPUT);
}

void loop() {
  digitalWrite(LED_PIN, HIGH);
  delay(300);
  digitalWrite(LED_PIN, LOW);
  delay(300);
}

Button-triggered PWM fade

// Digispark ATtiny85 - Fade an LED on P0 while a button on P2 is held.
// Wiring: LED + 220R resistor from P0 to GND; button from P2 to GND.
// Uses only P0/P1/P2, so USB uploads stay unaffected.

const int LED_PIN = 0;      // PWM capable
const int BUTTON_PIN = 2;   // input with pull-up

void setup() {
  pinMode(LED_PIN, OUTPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP);
}

void loop() {
  if (digitalRead(BUTTON_PIN) == LOW) {   // button held
    for (int b = 0; b <= 255; b += 5) {
      analogWrite(LED_PIN, b);
      delay(10);
    }
    for (int b = 255; b >= 0; b -= 5) {
      analogWrite(LED_PIN, b);
      delay(10);
    }
  } else {
    analogWrite(LED_PIN, 0);
  }
}

Frequently Asked Questions