little wire

Short Story

When i saw simpleavr's implementation of usbtiny on attiny45 , i thought it would be cool if i make a kit version of this with a minimal form factor. Then i designed a PCB and sent for first prototype. Later on i thought, if i want to sell this, it would be much cooler ,and more suitable with "Open Source Hardware" concept, if i bring this project one step ahead. So i tried to fit anything extra to the device and this Little Wire project came out.

Little Wire is multi-featured USB controlled Open Source Hardware tool packed in a minimal form factor designed by ihsan Kehribar.

I collaborated with the Seeedstudio and they produced an initial batch for me and Little Wire kits went online in June 2012. After that batch finished in April 2013, notice the time difference, I decided not to continue producing them through contract manifacturing. Currently, you can't buy readymade Little Wire kits but since this is an OSHW project, you are free and welcomed to produce your own version.

News: Digistump started selling adaptor kits for anyone wants to use their Digisparks with the Littlewire firmware more conveniently. You can check them out at from here:

Current firmware/software release version is v1.3. If your Little Wire isn't loaded with the v1.3 or the v1.2 firmware you can still use the old web site for reference or you can download the archive software/firmware releases from downloads page, but I advise you to upgrade your firmware. Below, you find how you can do this.


Experimental Features

Note: This tool has to take instructions at run-time over USB. It can't work in a computerless environment.

Pin Mapping

Silkscreen usbtinyisp Hard PWM Soft PWM ADC I2C SPI Onewire WS2812 CDC-232
pin1 MISO CH_B CH_2 - - DO - DATA TX
pin3 RESET - - CH_0 - CS - DATA -
pin4 MOSI CH_A CH_1 - SDA DI - DATA -

Software Support

When i first released Little Wire , it had native C,C++,C# and Processing support through custom libraries written by me. Later, maintaining multiple software libraries became a very demanding task. Therefore I dropped support for C++,C# and Processing libraries with the v1.3 release of Little Wire. If you still use your v1.0 / v1.1 firmware you can look at the archive releases to get support for those languages. Beware, software libraries are not backward/forward compatible and I definitely advice you to get the latest v1.2 firmware onto your device.

Doxygen documentation for the current C library can be found here:

For further support, please take a look at examples folder. If you want to contribute an example you can make a pull request so that I can add it to the main repo, or if you find a bug in one of the examples please open an issue ticket.

Ruby library: littlewire.rb

Even though this is not an official and complete library for the Little Wire, it is well developed and worth mentioning. This library is maintained by @Bluebie and covers most of the Little Wire features. If you are interested in controlling your Little Wire device from Ruby, it would be worth looking. You can find the details about this library here:

Firmware Upgrade / Installation

If you have a bare Attiny85 chip:

If your Attiny85 has micronucleus bootloader installed:

If your Attiny85 has fast tiny & mega UART bootloader installed:

If you bought your Little Wire from Seeedstudio:

Where are the pre-compiled binaries, drivers and archives?

You can find them from the downloads page:

Reference projects

Please note:

Do not use the Adafruit USB VID/PID without written permission from Adafruit Industries, LLC and 
Limor "Ladyada" Fried ( Permission is granted for littlewire, Ihsan Kehribar
and Seeed Studio by Adafruit Industries, LLC to use the Adafruit USB VID/PID for littlewire