2 layers65 × 58.5 mm
Opencollar carrier
open-pasture/opencollar
OpenCollar: a virtual-fence collar you can buy assembled or build from published parts.
91 partsApache-2.0
2 layers65 × 58.5 mm
Carrier
open-pasture/opencollarOpenCollar: a virtual-fence collar you can buy assembled or build from published parts.
- Size
- 65 × 58.5 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 100
- Nets
- 53
- Pads
- 292
- Tracks, vias
- 1,323, 335
- Pours
- 2
- Routed
- Yes
- KiCad
- KiCad 10.0 (file 20260206)
- Created
- 27 Sep 2026
- Updated
- 7 Nov 2026
Overview
Carrier is an open-source printed circuit board by open-pasture, from the open-pasture/opencollar repository on GitHub, published under the Apache-2.0 licence. It is a 2-layer board of 65 × 58.5 mm with 100 parts on 53 nets, routed with 1,323 tracks and 335 vias.
It is built around the W25Q128JVSIQ, USBLC6-2SC6 and BQ24074RGTR, with the MAX17260SETD+T, TCA4307DGK and TPS2553DBVR-1 among its other parts. Its parts include 26 resistors, 13 connectors, 12 capacitors, 7 ICs and 2 diodes.
Main components
12
W25Q128JVSIQ
SOIC-8-208mil-40℃~+85℃ 100,000 cycles 120ms@(32KB) 128Mbit 133MHz 1uA 2.7V~3.6V 20 Years 3ms Power-on reset、Hardware write protection、Software write protection、Write enable latch、Absolute write protection SPI SOIC-8-208mil NOR FLASH ROHSWinbondNOR FLASH
USBLC6-2SC6
SOT-23-60.35pF、0.8pF 100nA 150W@8/20us 15V 2 5V 6A@8/20us 6V ESD SOT-23-6 ESD and Surge Protection (TVS/ESD) ROHSUMWESD And Surge Protection (TVS/ESD)
BQ24074RGTR
QFN-16-EP(3x3)-40℃~+125℃ 1 1.5A 4.2V 4.35V~10.2V 6.5uA Charging IC Lithium Battery Not supported Support QFN-16-EP(3x3) Battery Management ROHSTexas InstrumentsBattery Management
MAX17260SETD+T
TDFN-14(3x3)-40℃~+85℃ 1 2.3V~4.9V 5.1uA I2C Lithium Battery、LiFePO4 Battery Monitoring IC Support TDFN-14(3x3) Battery Management ROHSMaxim Integrated (Analog Devices)Battery Management
TCA4307DGK
MSOP-8-40℃~+125℃ 10ns 2-Wire Bus 2-Wire Bus 2.3V~5.5V 400Kbps 5pF Buffer Bus capacitance isolation、Hot-swap protection、Power-off isolation MSOP-8 Signal Buffers, Repeaters, Splitters ROHSTexas InstrumentsSignal Buffers, Repeaters, SplittersTPS2553DBVR-1
SOT-23-6-40℃~+150℃ 1 1.5A 2.5V~6.5V 85mΩ Active High High Side Switch 过压保护、软启动、欠压锁定、反向电压保护、集成电荷泵、Overcurrent Protection、Over temperature protection、锁存保护、Short-Circuit Protection、反向电流阻断 SOT-23-6 Power Distribution Switches ROHSTexas InstrumentsPower Distribution Switches
B5819W
SOD-123-55℃~+125℃ 1.5A 1mA@40V 25A 40V 600mV@1A Standalone SOD-123 Schottky Diodes ROHSMDDSchottky Diodes
AO3401A
SOT-231 P-Channel 14nC@10V 30V 47mΩ@10V、60mΩ@4.5V、85mΩ@2.5V 4A 55pF 645pF 80pF 900mV SOT-23 MOSFETs ROHSAlpha & Omega SemiconductorMOSFETs
SM04B-SRSS-TB(LF)(SN)
SMD,P=1mm,卧贴-25℃~+85℃ 1 1A 1mm 1x4P 2.9mm 4 4.32mm 4P 50V 6mm Auxiliary Solder Pin Copper alloy PA SH Surface Mount, Right Angle Tin UL94V-0 White SMD,P=1mm,卧贴 Wire To Board Connector ROHSJSTWire To Board Connector
S8B-PH-SM4-TB(LF)(SN)
SMD,P=2mm,卧贴-25℃~+85℃ 1 100V 19.9mm 1x8P 2A 2mm 5.5mm 8 8.6mm 8P Auxiliary Solder Pin Beige Copper alloy PA PH Surface Mount, Right Angle Tin UL94V-0 SMD,P=2mm,卧贴 Wire To Board Connector ROHSJSTWire To Board Connector
ISM330BX
LGA-14L(2.5x3)-40℃~+85℃ 1.71V~3.6V 16bit 2.6uA 4.5KB IMU (accelerometer + gyroscope) Motion event detection、Synchronization and timestamp SPI、I2C、I3C X,Y,Z X,Y,Z ±4000dps ±8g LGA-14L(2.5x3) Accelerometers ROHSSTMicroelectronicsAccelerometers
SM03B-SRSS-TB(LF)(SN)
SMD,P=1mm,卧贴-25℃~+85℃ 1 1A 1mm 1x3P 2.9mm 3 3P 4.32mm 50V 5mm Auxiliary Solder Pin Copper alloy PA SH Surface Mount, Right Angle Tin UL94V-0 White SMD,P=1mm,卧贴 Wire To Board Connector ROHSJSTWire To Board Connector
README
README.mdOpenCollar
Open hardware virtual-fence collar. Off-the-shelf parts, open protocol, works with any software that speaks it.
Two collar types share as much as possible:
- Rook — base-station collar (LTE-M + GPS, larger battery)
- Starling — cheaper LoRa mesh-relay collar
Repo map
| Path | What |
|---|---|
docs/REPO-STRUCTURE.md | Layout, old→new moves, conventions, firmware target split |
docs/rook/ | Rook collar docs (flash / control / provision placeholders) |
docs/starling/ | Starling collar docs (same) |
docs/assembly/ | Assembly pointers |
docs/firmware/ | Pilot firmware spec and Rook gap list |
hardware/common/ | Shared CAD (dims, strap/clamp/insert), shared STLs |
hardware/rook/ | Rook Node V1 CAD, STLs, print profiles, fit audit |
hardware/starling/ | Starling skeleton (reuses common) |
hardware/carrier/ | Carrier PCB |
firmware/ | Zephyr firmware (see firmware/ARCHITECTURE.md for target layout) |
protocol/ | Wire protocol and vectors |
Design and build docs
docs/BUILD-LOG.md— dated record of every step, result, and decisiondocs/WELFARE-POLICY.md— cue limits, auto shut-off, and welfare events (review thresholds before pulse)docs/PROTOTYPE-V0.md— current state of the V0 prototypedocs/V1-DESIGN.md— the V1 collar design and cost estimatesdocs/MANUFACTURING.md— how we get to 1,000 collars, and why FCC and carrier approval matterdocs/BOARD-DESIGN.md— designing the custom board on a small budgetdocs/DESIGN-PHASE.md— board design toolchain and workflow (KiCad + SKiDL)docs/COLLAR-FIRST-PRINCIPLES.md— the slim collar worked out from first principlesdocs/TEST-FIXTURE.md— how every board gets tested, explained from zero, with picturesdocs/CARRIER-EXPLAINED.md— every part on the carrier board, what it does, and where it sits in the collardocs/STRATEGY.md— product strategy and licensinghardware/prototype-cart.md— parts for the first prototypehardware/orders-2026-09-26.md— what was ordered and paidhardware/tools.md— tools for building a collarhardware/bom.md— parts listhardware/photos/— build photos
Licence
OpenCollar is open so anyone can build, repair and improve their own collar.
| What | Licence | Folders |
|---|---|---|
| Firmware, scripts and the protocol | Apache-2.0 | firmware/, protocol/, and code anywhere else |
| Hardware and CAD (boards, enclosure, print files) | CERN-OHL-W-2.0 | hardware/ |
| Docs, photos and renders | CC BY 4.0 | docs/, hardware/photos/, hardware/*/renders/ |
In plain terms:
- Firmware and protocol: use them for anything, including closed products. Keep the copyright notice and NOTICE.
- Hardware: build, sell and change the boards and the enclosure. If you ship a modified version of these design files, publish your changes to them under the same licence. Your own add-ons can stay closed.
- Docs: reuse them with credit to openpasture.
Third-party files keep their own licences: firmware/boards/makerdiary/ (Apache-2.0, plus Nordic's 5-clause licence where its headers say so) and firmware/third_party/monocypher/ (CC0 or BSD-2-Clause).
The names openpasture and OpenCollar and the openpasture logo aren't covered by these licences; see NOTICE. Contributing: CONTRIBUTING.md.
Parts
100| Qty | Value | Footprint | References |
|---|---|---|---|
| 10 | 100k | R_0603_1608Metric | R6, R7, R8, R13, R16, R20, R21, R23, R25, R26 |
| 5 | 100n | C_0603_1608Metric | C5, C6, C7, C11, C12 |
| 5 | 4.7k | R_0603_1608Metric | R3, R14, R15, R18, R19 |
| 4 | GND | TestPoint_Pad_D1.0mm | TP10, TP11, TP12, TP13 |
| 4 | MountingHole | MountingHole_3.2mm_M3 | H1, H2, H3, H4 |
| 3 | 10k | R_0603_1608Metric | R1, R5, R17 |
| 3 | 10u/25V | C_0805_2012Metric | C2, C3, C4 |
| 3 | 1M | R_0603_1608Metric | R9, R10, R11 |
| 2 | 1k | R_0603_1608Metric | R2, R22 |
| 2 | 1u | C_0603_1608Metric | C8, C9 |
| 2 | B5819W | D_SOD-123 | D1, D2 |
| 2 | MountingHole | MountingHole_2.2mm_M2 | H5, H6 |
| 2 | USBLC6-2SC6 | SOT-23-6 | U4, U5 |
| 1 | 10m | R_0805_2012Metric | R24 |
| 1 | 10n | C_0603_1608Metric | C1 |
| 1 | 200k | R_0603_1608Metric | R12 |
| 1 | 3V3 | TestPoint_Pad_D1.0mm | TP6 |
| 1 | 470n | C_0603_1608Metric | C10 |
| 1 | 68k | R_0603_1608Metric | R4 |
| 1 | AO3401A | SOT-23 | Q1 |
| 1 | BAT | TestPoint_Pad_D1.0mm | TP1 |
| 1 | BQ24074RGT | VQFN-16-1EP_3x3mm_P0.5mm_EP1.68x1.68mm | U1 |
| 1 | CHG_CE | TestPoint_Pad_D1.0mm | TP30 |
| 1 | CHG_IN | TestPoint_Pad_D1.0mm | TP3 |
| 1 | CHG_OUT | TestPoint_Pad_D1.0mm | TP2 |
| 1 | CHG_PGOOD | TestPoint_Pad_D1.0mm | TP29 |
| 1 | CHG_STAT | TestPoint_Pad_D1.0mm | TP28 |
| 1 | Cue L | JST_SH_SM04B-SRSS-TB_1x04-1MP_P1.00mm_Horizontal | J11 |
| 1 | Cue R | JST_SH_SM04B-SRSS-TB_1x04-1MP_P1.00mm_Horizontal | J12 |
| 1 | EXT_3V3 | TestPoint_Pad_D1.0mm | TP7 |
| 1 | EXT_EN | TestPoint_Pad_D1.0mm | TP24 |
| 1 | EXT_INT | TestPoint_Pad_D1.0mm | TP25 |
| 1 | EXT_SCL | TestPoint_Pad_D1.0mm | TP23 |
| 1 | EXT_SDA | TestPoint_Pad_D1.0mm | TP22 |
| 1 | GNSS_PPS | TestPoint_Pad_D1.0mm | TP33 |
| 1 | GNSS_RESET_N | TestPoint_Pad_D1.0mm | TP32 |
| 1 | GNSS_SAFEBOOT | TestPoint_Pad_D1.0mm | TP31 |
| 1 | Harness M8 | JST_PH_S8B-PH-SM4-TB_1x08-1MP_P2.00mm_Horizontal | J13 |
| 1 | I2C_SCL | TestPoint_Pad_D1.0mm | TP21 |
| 1 | I2C_SDA | TestPoint_Pad_D1.0mm | TP20 |
| 1 | ISET | TestPoint_Pad_D1.0mm | TP27 |
| 1 | ISM330 | PinSocket_1x09_P2.54mm_Vertical_SMD_Pin1Right | J10 |
| 1 | KIT_EN | TestPoint_Pad_D1.0mm | TP19 |
| 1 | KIT_VBUS | TestPoint_Pad_D1.0mm | TP8 |
| 1 | KIT_VSYS | TestPoint_Pad_D1.0mm | TP9 |
| 1 | Kit 1-10 | PinSocket_1x10_P2.54mm_Vertical_SMD_Pin1Right | J1 |
| 1 | Kit 11-20 | PinSocket_1x10_P2.54mm_Vertical_SMD_Pin1Right | J2 |
| 1 | Kit 30-21 | PinSocket_1x10_P2.54mm_Vertical_SMD_Pin1Right | J4 |
| 1 | Kit 40-31 | PinSocket_1x10_P2.54mm_Vertical_SMD_Pin1Right | J3 |
| 1 | Kit J2 feed | PinHeader_1x02_P2.54mm_Vertical | J5 |
| 1 | M10S J3 | PinSocket_1x04_P2.54mm_Vertical_SMD_Pin1Right | J9 |
| 1 | M10S J5 | PinSocket_1x08_P2.54mm_Vertical_SMD_Pin1Right | J8 |
| 1 | MAX17260 | TDFN-14-1EP_3x3mm_P0.4mm_EP1.78x2.35mm | U6 |
| 1 | Panels A/GND/B | JST_SH_SM03B-SRSS-TB_1x03-1MP_P1.00mm_Horizontal | J6 |
| 1 | Qwiic spare | JST_SH_SM04B-SRSS-TB_1x04-1MP_P1.00mm_Horizontal | J7 |
| 1 | RESET | TestPoint_Pad_D1.0mm | TP16 |
| 1 | SOLAR_A | TestPoint_Pad_D1.0mm | TP4 |
| 1 | SOLAR_B | TestPoint_Pad_D1.0mm | TP5 |
| 1 | SWCLK | TestPoint_Pad_D1.0mm | TP15 |
| 1 | SWDIO | TestPoint_Pad_D1.0mm | TP14 |
| 1 | TCA4307 | VSSOP-8_3x3mm_P0.65mm | U2 |
| 1 | TPS2553 | SOT-23-6 | U3 |
| 1 | TS | TestPoint_Pad_D1.0mm | TP26 |
| 1 | UART_RX | TestPoint_Pad_D1.0mm | TP18 |
| 1 | UART_TX | TestPoint_Pad_D1.0mm | TP17 |
| 1 | W25Q128JVS | SOIC-8_5.3x5.3mm_P1.27mm | U7 |
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Questions
How big is the Carrier PCB?
It measures 65 × 58.5 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Carrier use?
100 parts, built around the W25Q128JVSIQ, USBLC6-2SC6, BQ24074RGTR and MAX17260SETD+T. 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 Carrier KiCad files?
From the open-pasture/opencollar repository on GitHub, at the commit this page was made from: the board is hardware/carrier/pcb/carrier.kicad_pcb. PCBKit opens the board in the browser, with nothing to install.
Can I use the Carrier design in my own project?
Its repository publishes it under the Apache-2.0 licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).