Skip to content
Branch: master
Find file History
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Type Name Latest commit message Commit time
Failed to load latest commit information.
brain slug.pdf

Brain Slug

This was a last minute addon we made for our badge this year. It's a basic PCB with ATtiny85 and 5x WS2812B LEDs.


  • 1x ATtiny85-20SU
  • 5x WS2812B LEDs
  • 1x 220 ohm 0805 Resistor
  • 1x 4.7k ohm 0805 Resistor
  • 1x 10k ohm 0805 Resistor
  • 1x 1uF 0805 Capacitor


The PCB was designed to be soldered easily by hand. Only a few surface mount parts. Note the rotation of the WS2812B LEDs changes.

The footprint used for the ATtiny85 barely fits, care should be taken when soldering to ensure all pins are connected


The brain slug contains a 10 pin ISP header. Use a USBASP (few bucks on Ebay) to flash the bootloader and firmware from Arduino. Arduino 1.6.9 was used to program our brain slugs. Bootloader should be set to 16Mhz PLL. The brain slug can be powered by the USBASP.


  • ATtiny Arduino Core
  • Adafruit NeoPixel Library


May never get to this, but if we revisit the project:

  • Fix ATtiny85 footprint
  • Put MCU into deep sleep during delays
  • Dim LEDs slightly
  • Change ISP header to TagConnect 2050 to clean up design
  • Change WS2812B LEDs to have same rotation
You can’t perform that action at this time.