57 lines
2.7 KiB
Markdown
57 lines
2.7 KiB
Markdown
# 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
|
|
|
|
# Learn how to solder SMD:
|
|
|
|
[See Slides (in German)](docs/FaSTGLET-Part4-Lötworkshop.pdf)
|
|
|
|
# PCB Manufacturing
|
|
|
|
I usually order from JLC with the cheapest options, make sure to choose the manual placement of the order number (marker already included in Silkscreen)
|
|
|
|
# Build instructions
|
|
|
|
Assembly Guides: [Board A](https://fasttube.de/bestueckung/FaSTGLETree/A.html), [Board B](https://fasttube.de/bestueckung/FaSTGLETree/B.html)
|
|
|
|
- It's recommended to make sure each PCB is in the best state it can be in first before combining them. Afterwards, soldering becomes more difficult.
|
|
- For SMD parts, always solder a single pad/pin first before continuing to others
|
|
- Pin 1 markings are the elongated silkscreen line and the dot/line on the IC
|
|
- LED directions are not marked. The LED arrow should always point to the tree trunk/inwards (Anode to tip of branch)
|
|
- There's no pattern to whether the LED or Resistor is on top on the LED branches. Always check the assembly guide!
|
|
- J9 is usually not populated, it's left for external power
|
|
- The THT LED atop should have its leads shortened to ~7-10mm
|
|
- The THT LED atop is oriented using the flat side of its rim. The Flat side goes to the straight line, the round side to the rounded line
|
|
- Keep in mind the Errata section below
|
|
|
|
# Errata
|
|
|
|
- [2022 version] There is a pull-up resistor missing for the button. A 10kOhm THT resistor can be soldered from the backside of the bin header to the battery holder.
|
|
- [2022 and 2023 version] Be careful to not scratch the pcb surfaces with the legs of the top LED in order not to create a short circuit
|
|
- [2024 version] There is a missing connection betreen R5 Pin 1 and +BATT. A bodge wire from R5 (outside) to the battery holder solder point is recommended. Otherwise, the push button functionality most likely does not work.
|
|
|
|
# Cost
|
|
|
|
~10€ BOM @ 30pcs
|
|
|
|
# Licensing
|
|
|
|
Licensed under CERN OHL, see LICENSE.txt
|