~derf / projects / Blinkenrocket v1.0
dark mode

Blinkenrocket is a rocket-shaped accessory with an 8x8 LED matrix display and the ability to show user-defined texts and animations. However, unlike most such devices, users do not need an AVR programmer or USB-TTL converter to upload new patterns. Instead, they are flashed via a website and a standard 3.5mm audio cable. Hardware support is not limited to computers, but includes any device which is able to play audio at a decent volume (such as most tablets and smartphones).

It was a group project by Chaosdorf and shackspace people; I had the pleasure of writing the firmware for the ATTiny88 microcontroller powering the device. Parts of it have since been modified to make audio transmissions more robust.

Key features are:

  • 8 MHz ATTiny88 microcontroller with direct (and slightly out-of-spec) LED matrix connection
  • 8 kB I²C EEPROM for animation storage; supports up to 248 different animations.
  • 3.5mm audio modem with forward error correction (utilizing David Cook's Hamming FEC implementation)

Further documentation and sources are located on the Blinkenrocket GitHub page. Some information in german is also available on the Chaosdorf wiki page.

Here is an early modem demonstration with a not-yet-ideal error correction setup.