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Lnurl card

lnurlcash·lnurl-card·hardware/lnurl-card.kicad_pcb

Lnurl card PCB layout, top view — open source ESP32 board by lnurlcash
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About the Lnurl card PCB

Lnurl card is an open source ESP32 PCB design by lnurlcash, published on GitHub. It is a 4-layer board measuring 85.6 × 54 mm, with 20 components from 19 distinct parts.

Its main chip is the ESP32-S3FH4R2, from the ESP32 family. Other key parts include the ST25R3916B, NTAG424DNA, CAP1208 and TLV62569. By type, the board carries 6 ICs, 2 connectors and 2 capacitors.

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

From the project

LNURLcard is a new credit-card-shaped, ESP32-based Lightning device with eInk display, USB-C, WiFi (online), NO BATTERY, NFC, a 4×4 keypad

KiCad 10 project for lnurl-card v1. See the top-level README.md for the full design (block diagram, component rationale, power budget, thickness stack-up, the dual-NFC-antenna problem).

This was scaffolded in two passes. The first had no KiCad installed at all — everything was hand-authored S-expression/JSON text, unverified. A real KiCad 10 install (with kicad-cli but, notably, no symbol or footprint libraries — see below) became available partway through, which changed what's trustworthy here:

Main components on the Lnurl card

ESP32-S3FH4R2ST25R3916BNTAG424DNACAP1208TLV62569

Lnurl card bill of materials (BOM)

20 components, 19 distinct parts — part numbers from the project's BOM.

QtyPartRefs
1
ESP32-S3FH4R2
U1
1
ST25R3916B
U3
1
NTAG424DNA
U4
2
CAP1208
U5, U6
1
TLV62569
U7
1
USB-C
J1
1
eInk-FPC
J2
1
TOUCH_PAD_0
PAD_TOUCH_PAD_0
1
TOUCH_PAD_1
PAD_TOUCH_PAD_1
1
TOUCH_PAD_2
PAD_TOUCH_PAD_2
1
TOUCH_PAD_3
PAD_TOUCH_PAD_3
1
TOUCH_PAD_4
PAD_TOUCH_PAD_4
1
TOUCH_PAD_5
PAD_TOUCH_PAD_5
1
TOUCH_PAD_6
PAD_TOUCH_PAD_6
1
TOUCH_PAD_7
PAD_TOUCH_PAD_7
1
TOUCH_PAD_8
PAD_TOUCH_PAD_8
1
TOUCH_PAD_9
PAD_TOUCH_PAD_9
1
1uF
C1
1
10uF
C2

Lnurl card design files

The KiCad project lives in the lnurlcash/lnurl-card repository on GitHub; these links point at the commit this page was built from.

Lnurl card: common questions

What microcontroller does the Lnurl card use?

The Lnurl card is built around the ESP32-S3FH4R2, from the ESP32 family.

How big is the Lnurl card PCB?

The Lnurl card measures 85.6 × 54 mm, has 4 copper layers and is 0.8 mm thick.

How many components are on the Lnurl card?

20 components, from 19 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 Lnurl card design files?

From the lnurlcash/lnurl-card 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 Lnurl card design in my own project?

The repository has no license, so all rights stay with lnurlcash. Use it as a reference, and ask the author before reusing the design.

Can I test firmware for the Lnurl card 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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