43 open source boards using the 74HCT138
Real designs built with the 74HCT138, from public GitHub projects: a quick way to see how others power, decouple and connect it. Each board comes with its KiCad files, full parts list and a render — and you can simulate its firmware on HardLabs.
AVR/Arduino8bit computer
vascofazza
297.2 × 180.3 mm327 parts2LMIT314
Rc2014-ym2149
electrified
100 × 50 mm25 parts2LCERN-OHL-P-2.078
SN76489
jblang
100 × 50 mm23 parts2LNo license52
ESP32Nestronic Game Music Synthesizer
dkonigsberg
127 × 114.3 mm82 parts2LNo license38
Msxdos2s
b3rendsh
99.8 × 64.1 mm35 parts2LCC-BY-NC-4.024
ISA EMS 2Mb
hkzlab
104.1 × 102.9 mm41 parts2LCC-BY-NC-4.023
Flock
skiselev
99.1 × 49.9 mm25 parts2LNo license19
GameController
99.1 × 49.9 mm53 parts2LNo license18
Minimax8085-apu ext
100 × 80 mm38 parts2LNo license13
SodaIDE v2 konami case
Danjovic
100 × 65.5 mm30 parts2LCC0-1.011
ISA QuadUART2
104.1 × 102.9 mm39 parts2LCC-BY-SA-4.09
RC2014 Tandy Sound Card
tebl
99.1 × 49.5 mm32 parts2LGPL-3.09
Raspberry PiPiPtr
jmlzone
101.6 × 141.7 mm379 parts4LNo license8
FISC
DoctorWkt
231.3 × 96.5 mm59 parts2LGPL-3.07
PICOpenAC1
davischris
191.5 × 97.6 mm71 parts2LGPL-3.04
23xx-Adapter
Beaupre-Circuit-Design
19.7 × 41.9 mm9 parts4LMIT3
Adcboard
sgs-lab
184 × 80 mm124 parts2LNo license2
FrontPanel
89Mods
258.1 × 122.9 mm118 parts2LMIT2
Rc-1024k
PickledDog
99.1 × 49.9 mm13 parts2LApache-2.02
Rc-256page
99.1 × 49.9 mm12 parts2LApache-2.02
TTL 6510 Computer
StefansAI
368.3 × 215.9 mm330 parts2LNo license1
SST-6809-V2.2
KenWillmott
100 × 100 mm46 parts4LMIT1
AVR/ArduinoRC6502 Apple 1 SBC
99.1 × 99.7 mm48 parts2LGPL-3.0192
Ab register
TomNisbet
102 × 96 mm60 parts2LMIT18
SodaIDE v2 patola case
100 × 64.7 mm30 parts2LCC0-1.011![Top view of IBX ][ HV Board](https://hip.fly.dev/v1/gallery/thumb/sgs-lab--ibxii--hvboard.svg)
IBX ][ HV Board
145 × 80 mm51 parts2LNo license2
TTL 6510 Computer
368.3 × 215.9 mm330 parts2LNo license1
InterruptAndKeyboard
daveho
150 × 90 mm37 partsNo license19
Soda IDE
100 × 65.5 mm29 parts2LCC0-1.011
GPIOExpansion
ja1umi
155 × 114 mm33 parts2LMIT10
Commodore VIC-20 BLK0/1/2/3/5 Expansion
BrettHallen
82.9 × 61 mm16 parts2LNo license4
RC6502 TIA NTSC
99.1 × 69.2 mm45 parts2LGPL-3.0192
CPUandGlueLogic
150 × 90 mm35 partsNo license19
Commodore VIC-20 8KB RAM Expansion
62.9 × 61.6 mm15 parts2LNo license4
Z80ram
99.8 × 49.9 mm19 parts2LMIT73
Raspberry PiZoxnoxious Backplane and VCA
brer-rabbit
133.8 × 102.9 mm86 parts4LGPL-3.068
The 74HCT138 in open source designs
The gallery holds 43 open source boards using the 74HCT138 from 29 GitHub repositories; a typical one measures about 100 × 90 mm and carries around 38 components.
90% are two-layer designs, the rest use four layers or more, and 60% carry an open source license.
The most starred is 8bit computer by vascofazza.
Parts used alongside the 74HCT138
Microcontrollers on boards using the 74HCT138
What boards using the 74HCT138 are built for
74HCT138: common questions
Where can I find a 74HCT138 reference design?
Each of the 43 boards on this page is a real design using the 74HCT138. Open one to see how it is wired up, with the full BOM, a render of the layout and links to its KiCad files.
What parts are used alongside the 74HCT138?
The 74HCT00, 74HCT32, 74HCT04, 74HCT245 and 74HCT74 appear in the most repositories here.
Which microcontrollers do boards using the 74HCT138 use?
Most are built on AVR/Arduino (3), Raspberry Pi (2), ESP32 (1) and PIC (1).
How big is a typical board using the 74HCT138?
The median is 100 × 90 mm, and 90% are two-layer designs.
What is the most popular open source board using the 74HCT138?
By GitHub stars, 8bit computer by vascofazza, with 314 stars.
Can I simulate one of these boards using the 74HCT138 before building it?
Yes. HardLabs turns a board's netlist and BOM into a working simulation, so you can boot and test firmware against it with no hardware on your desk.