2 layers10.5 × 21 mm FRED V1, the printed circuit board in 3D

FRED V1

This is the kicad project for the board.

Size: 10.5 × 21 mm
Copper layers: 2
Thickness: 1.6 mm
Parts: 17
Nets: 13
Pads: 34
Tracks, vias: 26, 15
Pours: 1
Routed: Yes
KiCad: KiCad 9.0 (file 20241229)
Created: 16 Aug 2026
Updated: 3 Oct 2026

Overview

FRED V1 is an open-source printed circuit board by 97Cweb, from the 97Cweb/FRED repository on GitHub. It is a 2-layer board of 10.5 × 21 mm with 17 parts on 13 nets, routed with 26 tracks and 15 vias.

It is built around the ATTINY402-SSN and SLHT33H. Its parts include 3 capacitors, 2 ICs, 1 resistor, 1 diode and 1 switch. It belongs with the AVR (ATmega, ATtiny) boards of this library.

Main components

README

README.md

FRED (Flashing Rear End Device)

Blinking red light on back of train

Pressing the button makes it stay red.

This is the kicad project for the board.

Parts

Qty	Value	Footprint	References
9	TestPoint	TestPoint:TestPoint_Pad_2.0x2.0mm	AC1, AC2, G1, LED-1, LED+1, P1, SW1, SW2, V1
2	22uF	Capacitor_SMD:C_0603_1608Metric_Pad1.08x0.95mm_HandSolder	C2, C3
1	0.1uF	Capacitor_SMD:C_0603_1608Metric_Pad1.08x0.95mm_HandSolder	C1
1	220	Resistor_SMD:R_1206_3216Metric_Pad1.30x1.75mm_HandSolder	R1
1	ATtiny402-SS	Package_SO:SOIC-8_3.9x4.9mm_P1.27mm	U1
1	SLHT33H	Package_TO_SOT_SMD:SOT-23	U2
1	SW_Push	TL1017AABF160QG:TL1017AABF160QG	SW3
1	~	TBS30M-TP:TBS30MTP	D1

Questions

How big is the FRED V1 PCB?

It measures 10.5 × 21 mm and has 2 copper layers, 1.6 mm thick.

What parts does the FRED V1 use?

17 parts, built around the ATTINY402-SSN and SLHT33H. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.

Where can I download the FRED V1 KiCad files?

From the 97Cweb/FRED repository on GitHub, at the commit this page was made from: the board is pcb/FRED V1/FRED V1.kicad_pcb and its schematic pcb/FRED V1/FRED V1.kicad_sch. PCBKit opens the board in the browser, with nothing to install.

Can I use the FRED V1 design in my own project?

Its repository states no licence, so its author keeps all rights: ask 97Cweb before reusing the design.

Category and platform

AVR (ATmega, ATtiny)

Project files

Show this board on your page

A live frame, for any web page

<iframe src="https://pcbkit.io/embed/boards/97cweb-fred" title="FRED V1 in PCBKit" width="100%" height="480" style="border:0;border-radius:12px" allow="fullscreen" loading="lazy"></iframe>

A picture

<img src="https://pcbkit.io/embed/boards/97cweb-fred.jpg" alt="FRED V1" width="1200" height="900">

A picture that opens the board, for a README

[![FRED V1](https://pcbkit.io/embed/boards/97cweb-fred.jpg?size=s)](https://pcbkit.io/boards/97cweb-fred)

Source

Repository: 97Cweb/FRED
Board file: pcb/FRED V1/FRED V1.kicad_pcb
Commit: 079b63d
Licence: Not stated
Copies: 2 copies in 1 repository

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