tgohle/0001-FireFly

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Thomas Gohle 0f067e7015 Update README.md

2025-09-07 13:18:41 +00:00

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ToGo-Lab FireFly Morse Blinker

DIY kit: ATtiny-based Morse blinker. Through-hole. No mains. Simple on purpose.
Default license: CC-BY-NC-4.0

Intro

This is my “Hello World” hardware project on the new ToGo-Lab server. Years ago I built a tiny Morse throwie: ATtiny + one LED + one resistor, plus firmware. This version adds a supercapacitor and small solar cells. It uses the LED as a light detector, so it only blinks in the dark.

It’s not a throwie anymore. Hang it anywhere with decent light (for charging) and dry conditions and let it blink Morse on its own during night.

Goal: a beginner-friendly DIY kit with clear docs and hackable firmware.

Checkout also the blog about this project Suggestions welcome. Open an issue or email tgohle@togo-lab.io.

Repo layout

0001_FireFly/
├─ KiCad/            # .kicad_pro, schematic, PCB, fabrication outputs
├─ CAD/              # 2D/3D mechanical drawings, panel outlines (if any)
├─ Programm/         # firmware source, hex, Makefiles / Arduino sketches
└─ Documentation/    # assembly guide, quick start, FAQ, photos, BOM CSV

Hardware

MCU: ATtiny45/85 (internal RC clock, no crystal).
I/O: 1× LED + series resistor. Unused pins broken out to breadboard-style pads.
Programming: external ISP programmer via Arduino IDE; PDIP-8 ATtiny45/85 footprint.
Power: 3V DC (coin cell & & solar cell + supercapacitor with Schottky diodes to extend battery power).
Safety: low voltage only. Observe polarity.
PCB: hackable; access to unused ATtiny pins.

PCB notes: big pads for beginners, clear silks, LED polarity marks, ISP near board edge for pogo-clip.

KiCad

Version: 7.x or newer recommended.
Open 0001_FireFly/KiCad/ToGo-Lab_FireFly.kicad_pro.
Run ERC/DRC and fix errors before fabrication.
Plot: Gerbers + drill. Add a README in KiCad/fab/ with board thickness, finish, mask color, and min track/space.
Optional: panel outline DXF/SVG in CAD/.

Firmware

Two paths. Use what you like.

A) Arduino IDE

Board core: any stable ATtiny45/85 core.
Clock: internal. No fuse change required for first tests.
Programmer: USBasp / AVRISPmkII / Arduino-as-ISP.
Open the sketch in 0001_FireFly/Programm/arduino/.
Set message and WPM in config.h. Build and Upload Using Programmer.

Timing: internal RC. Unit may run at 1 MHz (CKDIV8) by default—adjust F_CPU or disable CKDIV8.

B) avr-gcc + make

Toolchain: avr-gcc, avr-libc, avrdude.
cd 0001_FireFly/Programm/avr/ then make all → firefly.hex.
Flash: make flash (edit PROGRAMMER and PORT in the Makefile).
config.h holds CPU clock, WPM, brightness.

Assembly

Follow Documentation/ToGo-Lab_FireFly_Assembly_Guide.md.
First power-up: LED should blink test pattern. If not, recheck polarity and bridges.

Test / Bring-up

Visual check; no shorts.
Power at 3–5 V. Current < 10 mA idle.
Program firmware over ISP.
Verify Morse timing; adjust WPM in config.h if needed.
Optional: measure sleep current.

BOM

Documentation/ToGo-Lab_FireFly_BOM.csv is the source of truth.
Columns: Designator,Qty,Manufacturer,MPN,Alt1,Description,Notes.
Keep alternates for LED and MCU. Note lot/date codes in commit messages for production.

Files to fabricate

Gerbers and drill files from KiCad/fab/ (board house-ready).
Project file: 0001_FireFly/KiCad/ToGo-Lab_FireFly.kicad_pro.

Known constraints

Through-hole only. No reflow.
Minimal I/O to keep it beginner-friendly.
Low power is nice but optional; optimize after the basic release.

Roadmap (tech only)

v0.1-proto: breadboard + first PCB, single message, speed presets.
v1.0: build guide, BOM with alternates, pilot 10 units.
v1.1: docs polish, optional brightness setting, minor PCB tweaks.

Contributing

PRs and issues welcome. Keep it simple. Reproducible steps beat long essays.
Photos of your build go in Documentation/gallery/ with a short caption and license notice.

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