2 layers18 × 33 mm Chloroplast, the printed circuit board in 3D

Chloroplast

A pro micro form factor nRF52840 controller board

Size: 18 × 33 mm
Copper layers: 2
Thickness: 1 mm
Parts: 40
Nets: 56
Pads: 169
Tracks, vias: 768, 90
Routed: Yes
KiCad: KiCad 8.0 (file 20240108)
Created: 12 May 2026
Updated: 23 Jun 2026

Overview

Chloroplast is an open-source printed circuit board by badjeff, from the badjeff/chloroplast-pcb repository on GitHub. It is a 2-layer board of 18 × 33 mm with 40 parts on 56 nets, routed with 768 tracks and 90 vias.

It is built around the E73-2G4M08S1C, BQ25186DLHR and TYPE-C-31-M-12. Its parts include 11 resistors, 7 connectors, 6 capacitors, 6 diodes and 4 ICs. It belongs with the keyboards and input and power boards and the nRF52 and nRF5x boards of this library.

Main components

README

README.md

chloroplast

A nRF52840 controller with the Ebyte E73-2G4M08S1C module, TI BQ25186DLHR, and TI TPS7A0233PDBVR.

PCB

Online preview avaliable here, powered by KiCanvas.

Figure 1: PCB edgecuts dimension

Figure 2: PCB 3D View - 1.0mm FR4

Figure 3: Schematic

BOM

Designator	Footprint	Quantity	Value	LCSC Part #
C1,C2,C3,C4	0402	4	1uF	C52923
C5,C6	0402	2	10uF	C15525
D1	0402	1	GREEN LED	C20608784
D2	0402	1	BLUE LED	C434447
D3,D4	0402	2	NSR05F30NXT5G	C604339
L1	0603	1	10uH	C76798
R1,R2	0402	2	5K1	C25905
R3,R4,R5,R9	0402	4	10K	C25744
R6	0402	1	510K	C11616
R7	0402	1	4K7	C25900
R8	0402	1	1M	C2909328
R10	0402	1	820K	C2909386
R11	0402	1	2M	C2930015
U1	E73-2G4M08S1C	1	E73-2G4M08S1C	C356849
U2	DFN-10_2x2mm_P0.4mm	1	BQ25186DLHR	C44639442
U3	SOT-23-5	1	TPS7A0233PDBVR	C2887324
U4	WLCSP-4L	1	TPMAX40200ANS_T	C47117620
USBC1	USB_C_Receptacle	1	TYPE-C-31-M-12	C165948

SMD 0402 (Imperial) aka 1005 Metric.
Alternative LED pads (D5,D6) are layouted on back.

Board Characteristics

Copper layer count: 2
Board thickness: 1.0 mm
Board overall dimensions: 18.0 x 33.02 mm

Bootloader

This board uses Adafruit Bootloader. The board folder could be found at here. Bootloader flashing is recommended to follow the comprehensive guide on joric/nrfmicro/wiki/Bootloader.

Zephye/ZMK Board Config

Zephyr and ZMK board config could be found in chloroplast-zmk-module. ZMK sheild example could be found in shields/chlorotaro34.

License

Available under the CERN-OHL-P v2 permissive license.

Parts

Qty	Value	Footprint	References
4	10K	Resistor_SMD:R_0402_1005Metric	R3, R4, R5, R9
4	1uF	Capacitor_SMD:C_0402_1005Metric	C1, C2, C3, C4
2	10uF	Capacitor_SMD:C_0402_1005Metric	C5, C6
2	5K1	Resistor_SMD:R_0402_1005Metric	R1, R2
2	BLUE	LED_SMD:LED_0402_1005Metric	D2, D6
2	GREEN	LED_SMD:LED_0402_1005Metric	D1, D5
2	LOGO	logo:cp-text-0.9mm-only	G*, G*
2	LOGO	logo:cp-text-1.6mm-only	G*, G*
2	NSR05F30NXT5G	JLCImport:NSR05F30NXT5G	D3, D4
2	Pin Header	Connector_PinHeader_2.54mm:PinHeader_1x13_P2.54mm_Vertical	J3, J4
1	10uH	Inductor_SMD:L_0603_1608Metric	L1
1	1M	Resistor_SMD:R_0402_1005Metric	R8
1	2M	Resistor_SMD:R_0402_1005Metric	R11
1	4K7	Resistor_SMD:R_0402_1005Metric	R7
1	510K	Resistor_SMD:R_0402_1005Metric	R6
1	820K	Resistor_SMD:R_0402_1005Metric	R10
1	BQ25186DLHR	Package_DFN_QFN:DFN-10_2x2mm_P0.4mm	U2
1	Conn_01x02_Socket	Connector_PinHeader_1.27mm:PinHeader_1x02_P1.27mm_Vertical	J7
1	Conn_01x04_Socket	Connector_PinHeader_1.27mm:PinHeader_1x03_P1.27mm_Vertical	J8
1	E73-2G4M08S1C	JLCImport:E73-2G4M08S1C	U1
1	I2C	Connector_PinHeader_1.27mm:PinHeader_1x02_P1.27mm_Vertical	J9
1	SWD	Connector_PinHeader_1.27mm:PinHeader_1x04_P1.27mm_Vertical	J5
1	TPMAX40200ANS_T	Package_CSP:WLCSP-4_0.64x0.64mm_P0.35mm	U4
1	TPS7A0233PDBVR	Package_TO_SOT_SMD:SOT-23-5	U3
1	TYPE-C-31-M-12	Connector_USB:USB_C_Receptacle_HRO_TYPE-C-31-M-12	USBC1
1	USB	Connector_PinHeader_1.27mm:PinHeader_1x04_P1.27mm_Vertical	J6

Questions

How big is the Chloroplast PCB?

It measures 18 × 33 mm and has 2 copper layers, 1 mm thick.

What parts does the Chloroplast use?

40 parts, built around the E73-2G4M08S1C, BQ25186DLHR and TYPE-C-31-M-12. 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 Chloroplast KiCad files?

From the badjeff/chloroplast-pcb repository on GitHub, at the commit this page was made from: the board is chloroplast.kicad_pcb and its schematic chloroplast.kicad_sch. PCBKit opens the board in the browser, with nothing to install.

Can I use the Chloroplast design in my own project?

Its repository states no licence, so its author keeps all rights: ask badjeff before reusing the design.

Category and platform

Keyboards and input Power nRF52 and nRF5x

Topics

keyboard mouse nrf52840 pcb solar-powered zmk bq25186 tps7a02

Project files

Show this board on your page

A live frame, for any web page

<iframe src="https://pcbkit.io/embed/boards/badjeff-chloroplast-pcb" title="Chloroplast 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/badjeff-chloroplast-pcb.jpg" alt="Chloroplast" width="1200" height="900">

A picture that opens the board, for a README

[![Chloroplast](https://pcbkit.io/embed/boards/badjeff-chloroplast-pcb.jpg?size=s)](https://pcbkit.io/boards/badjeff-chloroplast-pcb)

Source

Repository: badjeff/chloroplast-pcb
Board file: chloroplast.kicad_pcb
Commit: 50bab30
Licence: Not stated

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