FaSTGLETree

Simple christmas tree from 2 PCBs with pseudo-random blinkenlights. Soldering workshop subject.

Features / Function

CR2023 coin cell for power
1-pos SMD dip switch for on/off
button for manual shifting
3 pin header with jumper for switching between timer and button for shifting
All ICs are low voltage (down to 2V / 2.5V) variants
- 555 Timer set at ~.5Hz
- SIPO 8 bit shift register for patterns
- Pattern scrambling with 2x4 NAND gates
- Feedback from 2 NANDs into shift register
16 SMD LEDs connected to shift register and NAND outputs
1 yellow THT LED always-on on top
- Transparently 3D-printable star cap

~10€ BOM @ 30pcs

Licensed under CERN OHL, see LICENSE.txt