HardLabs

Chroma badge

wisdom-km·chroma-badge·hardware/pcb/badge.kicad_pcb

Chroma badge PCB layout, top view — open source ESP32 board by wisdom-km

About the Chroma badge PCB

Chroma badge is an open source ESP32 PCB design by wisdom-km, published on GitHub under the Custom license license. It is a 2-layer board measuring 91 × 84 mm, with 52 components from 29 distinct parts.

Its main chip is the ESP32-C3-MINI-1-N4, from the ESP32 family. Other key parts include the ST25DV64KC-IER6S3, TP4054 and XC6220B331MR-G. By type, the board carries 20 capacitors, 15 resistors, 5 diodes, 4 ICs, 3 connectors and 2 transistors.

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

From the project

Open-source color e-ink name badge — hardware, firmware, and companion software.

仓库：https://github.com/wisdom-km/chroma-badge

一块 6.3 mm 厚的电子工牌：4.2" 黑白红黄四色墨水屏 + ESP32-C3（Wi-Fi/BLE/原生 USB）+ ST25DV64KC NFC + ≤2 mm 超薄锂电 + USB-C。固件目前是 v0.2 上电自检；手机传图（F2）未写。

用 Cursor 打开这个文件夹（本地 Agent）。根目录 AGENTS.md 和 .cursor/rules/badge.mdc 会带上约定。

- LICENSE.md：硬件 CERN-OHL-P-2.0，固件/脚本 MIT - AGENTS.md：硬性约定与当前进度 - docs/01-architecture-decisions.md：选型 - docs/02-bom-and-cost.md：BOM；屏贴胶 3M 467MP - docs/03-handoff.md：复现步骤与当前板指纹 - docs/09-process.md：CI、生产包、贴胶 - hardware/pcb/：由 scripts/design.py 生成 - firmware/README.md：v0.2 自检；不要覆盖 output/badge-42c-v0.1.bin`

Chroma badge, from the project README
From the project README

Main components on the Chroma badge

ESP32-C3-MINI-1-N4ST25DV64KC-IER6S3TP4054XC6220B331MR-G

Chroma badge bill of materials (BOM)

52 components, 29 distinct parts — part numbers from the project's BOM.

QtyPartRefs
1
ESP32-C3-MINI-1-N4
U1
1
ST25DV64KC-IER6S3
U2
1
TP4054
U3
1
XC6220B331MR-G
U4
1
SI1308EDL
Si1308EDL
Q1
1
AO3401A
Q2
1
C262657
EPD FPC 24P 0.5mm
J1
1
C145956
BATT JST-SHL 1.0mm
J2
1
C223907
USB-C 16P 沉板 (TYPE-C-31-M-14)
J3
1
C221929
RESET
SW1
1
C221929
BOOT/USER
SW2
3
MBR0530
D1, D2, D3
1
RED
D4
1
GREEN
D5
1
47UH
47uH
L1
3
4.7U
4.7u
C1, C2, C4
3
10U
10u
C3, C6, C12
3
100N
100n
C5, C7, C9
4
1u
C8, C10, C13, C14
1
4.7U/25V
4.7u/25V
C15
Show 9 more
QtyPartRefs
2
1U/50V
1u/50V
C16, C17
4
1U/25V
1u/25V
C18, C19, C20, C21
3
5.1K
5.1k
R1, R2, R3
2
1k
R4, R9
3
1M
R5, R6, R15
3
10K
10k
R7, R8, R10
2
4.7K
4.7k
R11, R12
1
100K
100k
R13
1
2.2R
R14

Chroma badge design files

The KiCad project lives in the wisdom-km/chroma-badge repository on GitHub; these links point at the commit this page was built from.

Chroma badge: common questions

What microcontroller does the Chroma badge use?

The Chroma badge is built around the ESP32-C3-MINI-1-N4, from the ESP32 family.

How big is the Chroma badge PCB?

The Chroma badge measures 91 × 84 mm, has 2 copper layers and is 0.8 mm thick.

How many components are on the Chroma badge?

52 components, from 29 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 Chroma badge design files?

From the wisdom-km/chroma-badge 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 Chroma badge design in my own project?

It is published under Custom license, which limits how it may be reused; read the license before building on it.

Can I test firmware for the Chroma badge 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.

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