# Digispark ATtiny85 not recognised on Windows: driver and the 5 second window

> Fix a Digispark that will not upload: install the Digispark driver, plug it in only when the IDE asks and use a short cable or a hub-free port.

Canonical: https://roboticsengineering.in/fix/digispark-attiny85-driver-windows-not-recognised/ | Published: 2026-11-03 | Updated: 2026-11-04

**Start the upload, and plug the board in only when the IDE asks you to.** The bootloader runs for about five seconds.

## What the message means

The Digispark has no USB chip. It starts a bootloader after power-up, and the computer needs a driver for it.

## Fix it in this order

1. Install the board support package and the USB driver for the Digispark.
2. Unplug the board, start the upload, and plug it in when the IDE says so.
3. Wait for the upload to finish before the program starts.
4. Use a different USB port, preferably directly on the computer.
5. Use a short cable, since long ones cause failures.
6. Check the power: the board needs a steady supply.

## Why it happens

The Digispark has no USB chip. The ATtiny85 runs a small bootloader called Micronucleus that bit-bangs USB, and it only listens for roughly five seconds after power-up. After that the board runs your sketch and the computer sees nothing, which is why plugging it in before the IDE is ready fails. Windows also needs the Digispark driver package installed, because it does not know the device.

A long or thin cable, a hub, or a USB 3 port can make the timing fragile. Use a short data cable on a port directly on the computer.

## If you see this, do this

| You see | Do this |
| --- | --- |
| Device not recognised | Driver. |
| Upload times out | Plug in at the right moment. |

## Related

[board not detected](https://roboticsengineering.in/fix/arduino-nano-clone-not-detected-ch340-driver/), [ATtiny85 PWM pins](https://roboticsengineering.in/fix/attiny85-pwm-pins-and-timer-limits/).

Last reviewed: November 2026. These are the usual causes and the order that finds them fastest. Test on your own board; clones and cables differ.

## Why this happens

The Digispark carries the Micronucleus bootloader. It does not appear as a normal serial port. After plug-in it runs the bootloader for a few seconds, about five, waiting to be sent a program; if none arrives, it starts the program already stored. That is why the upload tool asks you to plug the board in only after you click upload, and why the board seems to vanish if you wait too long.

For the computer to talk to the bootloader on Windows, a driver for the Micronucleus device (a libusb-type driver) must be installed. Without it, Device Manager shows an unknown device and the upload tool reports that it cannot find the device. USB hubs and some USB 3 ports also fail with this bootloader.

## How to confirm the cause

- Open Device Manager while plugging the board in. Look for a Digispark or Micronucleus entry within the first few seconds. A yellow-marked unknown device suggests a missing driver.
- Plug the board into a USB 2 port on the computer directly, not through a hub, and try again.
- Check the board setting: choose the Digispark option for the ATtiny85 board in your IDE.
- Watch the tool’s message. ‘Plug in device now’ means do it at that moment, not before.
- Try a different data cable; some cables carry power only.

## Worked example

The order of steps for a first upload. No code is needed; it is the sequence that matters.

```
1. Board unplugged from USB.
2. Select the Digispark board in the IDE.
3. Click Upload and wait for the line:
     "Plugin device now ... (will timeout in 60 seconds)"
4. Plug the board in directly now.
5. Within a few seconds the upload runs and prints "Running ...".
6. If Device Manager shows an unknown device, install the
   Micronucleus driver and repeat from step 1.
```

## Common mistakes

- Plugging the board in first, then clicking upload.
- Using a front-panel hub or a USB 3 port that fails to see the device.
- Choosing an Arduino Uno board setting.
- Skipping the driver step on a fresh Windows installation.
- Writing a program larger than the free space, about 6 KB, left after the bootloader.

## If this did not fix it

- A faulty or counterfeit board without the bootloader.
- A cable that only supplies power.
- A security setting or driver signature check that blocks the unsigned driver.
- Using pin P5 as an input after its reset function was changed, which stops reset and uploads working as expected.