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)
├─ Program/          # 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.
Burning Attiny: 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. (big pads for beginners, clear silks, LED polarity marks)

Firmware / Arduino IDE

Follow Documentation/ToGo-Lab_FireFly_ArduinoIDE_Program_Guide.md.
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/Program/.

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 current.

BOM

Follow Documentation/ToGo-Lab_FireFly_BOM.csv as source of truth.

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. Photos of your build you send me go in Documentation/gallery/ with a short caption and license notice.

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