4 layers117.5 × 30 mm 4reel ee, the printed circuit board in 3D

4reel ee

Stereo machine vision camera for outdoor mobile robotics.

Size: 117.5 × 30 mm
Copper layers: 4
Thickness: 1.56 mm
Parts: 179
Nets: 204
Pads: 794
Tracks, vias: 2,099, 453
Pours: 11
Routed: Yes
KiCad: KiCad 10.0 (file 20260206)
Created: 21 Jul 2026
Updated: 11 Oct 2026

Overview

4reel ee is an open-source printed circuit board by o7-machinehum, from the o7-machinehum/4reel repository on GitHub, published under the MIT licence. It is a 4-layer board of 117.5 × 30 mm with 179 parts on 204 nets, routed with 2,099 tracks and 453 vias.

It is built around the RV1106G3, RTL8723DS-CG and TPS62A01ADRL, with the DM3AT-SF-PEJM5, OV9281 and EA3036CQBR among its other parts. Its parts include 93 capacitors, 34 resistors, 11 inductors, 10 ICs and 4 connectors.

Main components

README

readme.md

4reel

4reel is a platform for robots that don't have enough computing power to run machine vision algorithms. It's capable of stereo depth processing, image classification and SLAM.

When connected over USB-C the device will present itself as an Ethernet adapter and DHCP you an IP address, configuration can be done on the web portal at http://192.168.77.1:8080/

The JST connecter can be used to send data UART to an Arduino, ESP32, etc. The same JST conncetor can be used to power the device with 5V. Main image

System Overview

4reel RV1103 board block diagram

Repo structure

bash

.
|-- img
|-- os
|-- readme.md
|-- ref
|-- rv1103    # Current tested board
|-- rv1106    # Next generation
`-- scripts   # Automation scripts I wrote

Media

https://youtube.com/shorts/XkLzl0wEfN4?si=KPXePSXCayTTsI1j

Parts

179

Qty	Value	Footprint	References
24	10uF	Capacitor_SMD:C_0402_1005Metric	C2, C3, C4, C10, C12, C13, C17, C19, C20, C21, C22, C23, C25, C26, C27, C31 +8
22	1uF	Capacitor_SMD:C_0402_1005Metric	C29, C30, C33, C34, C35, C39, C40, C43, C44, C46, C47, C48, C55, C56, C57, C58 +6
21	100nF	Capacitor_SMD:C_0402_1005Metric	C1, C14, C15, C16, C36, C37, C41, C42, C45, C49, C51, C52, C53, C61, C62, C63 +5
13	100nF	Capacitor_SMD:C_0201_0603Metric	C18, C24, C28, C75, C76, C78, C80, C86, C87, C88, C89, C90, C91
6	3u3/0.9A	Inductor_SMD:L_0805_2012Metric	L4, L5, L6, L7, L8, L9
6	Fiducial	Fiducial:Fiducial_0.5mm_Mask1.5mm	FID1, FID2, FID3, FID4, FID5, FID6
5	100k	Resistor_SMD:R_0402_1005Metric	R4, R6, R9, R16, R34
5	10uF	Capacitor_SMD:C_0603_1608Metric	C81, C83, C84, C85, C92
4	0R	Resistor_SMD:R_0402_1005Metric	R13, R30, R32, R36
4	1k	Resistor_SMD:R_0402_1005Metric	R23, R24, R29, R33
4	4.7k	Resistor_SMD:R_0402_1005Metric	R11, R12, R21, R22
4	M2	MountingHole:MountingHole_2.2mm_M2	H1, H2, H3, H4
4	TestPoint	TestPoint:TestPoint_Pad_1.0x1.0mm	TP3, TP4, TP5, TP6
3	1.5uH	Inductor_SMD:L_1008_2520Metric	L1, L2, L3
3	220pF	Capacitor_SMD:C_0402_1005Metric	C6, C8, C11
3	NC	Capacitor_SMD:C_0402_1005Metric	C73, C74, C82
2	10k	Resistor_SMD:R_Array_Convex_4x0402	RN3, RN4
2	10k	Resistor_SMD:R_0402_1005Metric	R8, R35
2	10pF	Capacitor_SMD:C_0402_1005Metric	C32, C38
2	200k	Resistor_SMD:R_0402_1005Metric	R5, R7
2	22R	Resistor_SMD:R_0201_0603Metric	R27, R28
2	47k	Resistor_SMD:R_Array_Concave_4x0402	RN1, RN2
2	5.6k	Resistor_SMD:R_0402_1005Metric	R14, R15
2	Camera_Lens_20mm	ov9281:Camera_Lens_20mm	MP1, MP2
2	ImageSensor_OV9281	ov9281:OV9281	U3, U9
2	LED	LED_SMD:LED_0402_1005Metric	D1, D2
2	TXC-7C	Oscillator:Oscillator_SMD_TXC_7C-4Pin_5.0x3.2mm	Y1, Y3
2	TestPoint	TestPoint:TestPoint_Pad_1.5x1.5mm	TP1, TP2
1	100K	Resistor_SMD:R_0402_1005Metric	R31
1	10K	Resistor_SMD:R_0402_1005Metric	R25
1	120R@100MHz	Inductor_SMD:L_0603_1608Metric	L10
1	1M	Resistor_SMD:R_0402_1005Metric	R20
1	1uH	Inductor_SMD:L_1008_2520Metric	L11
1	22R	Resistor_SMD:R_0402_1005Metric	R19
1	240R	Resistor_SMD:R_0201_0603Metric	R10
1	24Mhz	Crystal:Crystal_SMD_2016-4Pin_2.0x1.6mm	Y2
1	40.2k	Resistor_SMD:R_0402_1005Metric	R1
1	47k	Resistor_SMD:R_0402_1005Metric	R3
1	80k	Resistor_SMD:R_0402_1005Metric	R17
1	9.1k	Resistor_SMD:R_0402_1005Metric	R2
1	Conn_Coaxial	Connector_Coaxial:U.FL_Hirose_U.FL-R-SMT-1_Vertical	J3
1	EA3036C	Package_DFN_QFN:QFN-20-1EP_3x3mm_P0.4mm_EP1.65x1.65mm	U2
1	JST	Connector_JST:JST_SH_SM04B-SRSS-TB_1x04-1MP_P1.00mm_Horizontal	J4
1	LIS2HH12	Package_LGA:LGA-12_2x2mm_P0.5mm	U8
1	Micro_SD_Card_Det2	Connector_Card:microSD_HC_Hirose_DM3AT-SF-PEJM5	J2
1	RTL8723DS	KiLib:RTL8723	U10
1	RV1106G3	rv1106:Rockchip_QFN-128-1EP_12.3x12.3mm_P0.35mm_EP7x7mm	U1
1	TLV73312PDBV	Package_TO_SOT_SMD:SOT-23-5	U4
1	TLV73328PDBV	Package_TO_SOT_SMD:SOT-23-5	U6
1	TPD2EUSB30	Package_TO_SOT_SMD:Texas_DRT-3	U5
1	TPS62A01ADRL	Package_TO_SOT_SMD:SOT-563	U7
1	USB_C_Receptacle_USB2.0_16P	Connector_USB:USB_C_Receptacle_GCT_USB4105-xx-A_16P_TopMnt_Horizontal	J1

Questions

How big is the 4reel ee PCB?

It measures 117.5 × 30 mm and has 4 copper layers, 1.56 mm thick.

What parts does the 4reel ee use?

179 parts, built around the RV1106G3, RTL8723DS-CG, TPS62A01ADRL and DM3AT-SF-PEJM5. 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 4reel ee KiCad files?

From the o7-machinehum/4reel repository on GitHub, at the commit this page was made from: the board is rv1106/4reel_ee.kicad_pcb and its schematic rv1103/4reel_ee.kicad_sch. PCBKit opens the board in the browser, with nothing to install.

Can I use the 4reel ee design in my own project?

Its repository publishes it under the MIT licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).

Show this board on your page

A live frame, for any web page

<iframe src="https://pcbkit.io/embed/boards/o7-machinehum-4reel-4reel-ee-2" title="4reel ee 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/o7-machinehum-4reel-4reel-ee-2.jpg" alt="4reel ee" width="1200" height="900">

A picture that opens the board, for a README

[![4reel ee](https://pcbkit.io/embed/boards/o7-machinehum-4reel-4reel-ee-2.jpg?size=s)](https://pcbkit.io/boards/o7-machinehum-4reel-4reel-ee-2)

Source

Repository: o7-machinehum/4reel
Board file: rv1106/4reel_ee.kicad_pcb
Commit: 292b176
Licence: MIT

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