2 layers53.9 × 23.2 mm Buffer, the printed circuit board in 3D

Buffer

Bare-metal Raspberry Pi project that provides pixel-perfect sampling of Retro Computer RGB/YUV video and conversion to HDMI

Open in PCBKit

Size: 53.9 × 23.2 mm
Copper layers: 2
Thickness: 1.6 mm
Parts: 11
Nets: 27
Pads: 62
Tracks, vias: 144, 3
Pours: 2
Routed: Yes
KiCad: KiCad 5 (file 20171130)
Created: 24 Apr 2017
Updated: 18 May 2026

Overview

Buffer is an open-source printed circuit board by hoglet67, from the hoglet67/RGBtoHDMI repository on GitHub, published under the GPL-3.0 licence. It is a 2-layer board of 53.9 × 23.2 mm with 11 parts on 27 nets, routed with 144 tracks and 3 vias.

It is built around the 74LS245SC. Its parts include 6 connectors, 1 capacitor, 1 IC and 1 diode. It belongs with the interfaces and adapters and lEDs and displays boards of this library.

Main components

74LS245SC
-0℃~+70℃ 12ns@5V,45pF 15mA 24mA 4.75V~5.25V 74LS 8 Bidirectional Output enable Schmitt trigger Tri-State - Buffers, Drivers, Receivers, Transceivers ROHSTexas InstrumentsBuffers, Drivers, Receivers, Transceivers

README

README.md

RGBtoHDMI

The RGBtoHDMI interface converts the "digital" RGB video signal from the BBC Micro or Electron to HDMI compatible with most modern TV/Monitors. The interface comprises a Raspberry Pi Zero and a specially designed Hat containing a small CPLD. Custom firmware on the Raspberry Pi, in conjunction with the CPLD, is able to correctly sample each of the Beeb's video modes to give a pixel-perfect rendition.

For more information, see the project Wiki.

Parts

Qty	Value	Footprint	References
2	470R	Resistor_THT:R_Array_SIP5	RN1, RN2
2	Conn_01x01	Connector_PinHeader_2.54mm:PinHeader_1x01_P2.54mm_Vertical	P6, P7
1	100n	Capacitor_SMD:C_0805_2012Metric_Pad1.15x1.40mm_HandSolder	C1
1	74LS245	Package_SO:SOIC-20W_7.5x12.8mm_P1.27mm	U1
1	Conn_01x04	Connector_PinHeader_2.54mm:PinHeader_1x04_P2.54mm_Vertical	P2
1	Conn_01x05_CUSTOM_EVEN	Connector_Harwin:Harwin_M20-89005xx_1x05_P2.54mm_Horizontal_CUSTOM_EVEN	P5
1	Conn_01x05_CUSTOM_ODD	Connector_Harwin:Harwin_M20-89005xx_1x05_P2.54mm_Horizontal_CUSTOM_ODD	P4
1	Conn_02x06_Odd_Even	Connector_PinSocket_2.54mm:PinSocket_2x06_P2.54mm_Horizontal	P1
1	D_Schottky	Diode_SMD:D_SOD-123F	D1

Questions

How big is the Buffer PCB?

It measures 53.9 × 23.2 mm and has 2 copper layers, 1.6 mm thick.

What parts does the Buffer use?

11 parts, built around the 74LS245SC. 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 Buffer KiCad files?

From the hoglet67/RGBtoHDMI repository on GitHub, at the commit this page was made from: the board is kicad_Extender_6_bit_buffer/V1/buffer.kicad_pcb. PCBKit opens the board in the browser, with nothing to install.

Can I use the Buffer design in my own project?

Its repository publishes it under the GPL-3.0 licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).

Category and platform

Interfaces and adapters LEDs and displays

Project files

Show this board on your page

A live frame, for any web page

<iframe src="https://pcbkit.io/embed/boards/hoglet67-rgbtohdmi-buffer-2" title="Buffer 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/hoglet67-rgbtohdmi-buffer-2.jpg" alt="Buffer" width="1200" height="900">

A picture that opens the board, for a README

[![Buffer](https://pcbkit.io/embed/boards/hoglet67-rgbtohdmi-buffer-2.jpg?size=s)](https://pcbkit.io/boards/hoglet67-rgbtohdmi-buffer-2)

Source

Repository: hoglet67/RGBtoHDMI
Board file: kicad_Extender_6_bit_buffer/V1/buffer.kicad_pcb
Commit: 3c31517
Licence: GPL-3.0

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