AlexWayne<Codes>

This project was a custom electronics journey. It’s a small circular pendant with seven RGB LEDs. The hardware and software were completely custom, right down to the PCBs, firmware, and enclosure.

Features

• 8 animation modes
  • Rainbow - Hues swirl
  • Red - Slow rotating fade, like hot magma
  • Orange - Dual pulses from the center and outer ring dance together
  • Yellow - Sparking slightly chaotic flames
  • Green - Soft swirling heartbeat
  • Blue - Vibrating as if holding a high note
  • Indigo - Two orbs orbit a pulsing center
  • Violet - Alternating sets of three, pulse between each other
  • Showcase - Rotates through all animation modes
• One-button interface
  • Hold to turn on/off
  • Tap to change animation modes
  • Hold longer while the pendant is on to enter showcase mode
• Built-in battery, USB rechargeable
• Charging status lights: amber while charging, green when fully charged
• Ultra-low power consumption when off, despite no mechanical off switch

Build

• 1 custom front PCB for the LEDs
• 150 mAh LiPo battery
• 1 custom back PCB for the microcontroller and battery charging
• 7 APA102 addressable RGB LEDs
• 1 ATTiny84 microcontroller
• 2 battery status LEDs
• 1 momentary switch
• 1 battery charging controller
• Assorted resistors and capacitors
• Surface-mount components, soldered using a converted toaster oven
• Custom two-piece, 3D-printed enclosure