ATtiny85-based illuminated PCB keychain featuring the Blacker Hovse crest
Blacker Hovse (House) is one of the eight student houses in the undergraduate housing system at Caltech. Blacker was founded in 1932 and named after Robert Roe Blacker, a trustee of Caltech. Notable alumni from Blacker include William Shockley, Walter Munk, Carver Mead, and Kip Thorne. The current house motto is Sed nvlla nisi ardva virtvs.
This is a 1.6" by 1.9" PCB keychain featuring the Blacker Hovse crest on the top copper, based on RuddBlink. A ring of 8 LEDs around the crest is controlled by an ATtiny85 through a 74HC595 shift register. This keychain is intended to be compact and aesthetic, but also simple to solder; all packages are SOIC and 0805 or larger.
The keychain can be powered by a single CR2032 coin cell through the coin cell holder footprint on the back, or through an alternative power source soldered to those pads.
- ATtiny85 in SOIC-8 package driving 74HC595 shift register in SOIC-16 package
- PWM-able output
- Power switch
- User pushbutton
- MOSFET polarity protection
- PTC fuse
- Aesthetics
No input voltage regulation is present. Do not apply more than 5.5 V, the maximum voltage for the ATtiny.
This PCB is designed with KiCad EDA 5.1.4. Schematic and board files may be found under /moleblink, with documentation under /moleblink/doc.
- Ray Sun - Undergraduate, Electrical Engineering, Caltech, Class of 2020
Unless otherwise noted, this schematic and PCB design, with associated symbol and footprint files, are licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
