HardLabs

UCB32

Majklzbastlirny·NixieClock·PCB_Sources/ucb vibecheck_final/UCB32.kicad_pcb

UCB32 PCB layout, top view — open source ESP32 board by Majklzbastlirny
Simulate this board

About the UCB32 PCB

UCB32 is an open source ESP32 PCB design by Majklzbastlirny, published on GitHub under the GPL-3.0 license. It is a 2-layer board measuring 56.5 × 39.7 mm, with 49 components from 24 distinct parts.

Its main chip is the ESP32-WROOM-32, from the ESP32 family. Other key parts include the AP2127R-3.3. By type, the board carries 21 resistors, 9 transistors, 7 crystals, 4 capacitors, 3 diodes and 2 ICs.

It belongs with the iot & wireless, sensors and displays & leds designs in this gallery.

From the project

ESP-IDF firmware for a 6-tube multiplexed ESP32 nixie clock (WiFi/SNTP, Home Assistant, web UI, alarm, temperatures)

ESP-IDF + PlatformIO firmware for a 6-tube multiplexed nixie clock, replacing the original ESPHome config (nixieclock.yaml, kept for reference). WiFi is used for time sync and remote control; the clock keeps running (and keeps time, via its RTC) with no network.

ESP32 (WROOM-32) on the UCB32 controller board driving the Unidisp display board:

- Onboard UC3845 HV supply (~180 V, no dimming input → brightness is done in firmware by PWM-ing each tube's anode within its multiplex slot — the headline feature that wasn't possible under ESPHome). - MH74141 BCD cathode driver (old/slow Tesla part)…

UCB32, from the project README
From the project README

Main components on the UCB32

AP2127R-3.3ESP32-WROOM-32

UCB32 bill of materials (BOM)

49 components, 24 distinct parts — part numbers from the project's BOM.

QtyPartRefs
1
AP2127R-3.3
U1
1
ESP32-WROOM-32
U2
8
BSS138
Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8
1
AO3403
Q9
1
snooze
X1
2
Conn_01x07_Socket
X2, X3
1
BAT
X4
1
I2C
X5
1
Dallas
X6
1
Prog
X7
1
Speaker
LS1
1
Bootsel
SW1
1
RST
SW2
1
SS14
D1
1
LED
D2
1
1N4148
D3
1
47u
C1
2
100n
C2, C3
1
10u
C4
11
4k7
R1, R2, R3, R4, R5, R6, R7, R8 +3
Show 4 more
QtyPartRefs
5
10k
R9, R14, R15, R18, R19
2
470
R16, R17
1
1k
R21
2
22k
R22, R23

UCB32 design files

The KiCad project lives in the Majklzbastlirny/NixieClock repository on GitHub; these links point at the commit this page was built from.

UCB32: common questions

What microcontroller does the UCB32 use?

The UCB32 is built around the ESP32-WROOM-32, from the ESP32 family.

How big is the UCB32 PCB?

The UCB32 measures 56.5 × 39.7 mm, has 2 copper layers and is 1.6 mm thick.

How many components are on the UCB32?

49 components, from 24 distinct parts, with part numbers taken from the project's own BOM. The full bill of materials is listed on this page.

Where can I download the UCB32 design files?

From the Majklzbastlirny/NixieClock repository on GitHub, which has the KiCad layout, the schematic and the BOM; the links under Design files point to each one.

Can I use the UCB32 design in my own project?

Yes, under the terms of its GPL-3.0 license, which Majklzbastlirny chose for the repository.

Can I test firmware for the UCB32 without the hardware?

Yes. HardLabs builds a simulation of the board from its netlist and BOM, so you can run and debug ESP32 firmware against it before you order a PCB.

More boards in NixieClock

Similar boards