4 layers58.4 × 62.2 mm
Daybreak mk3b
reedtaylor/daybreak_mk3
A PCB interface between the Decent Espresso DE1 and USB or Adafriuit Feather HUZZAH32 EESP32
63 parts3
2 layers87 × 68 mm
Modbus RJ45-Breakout
the78mole/ModBus-RJ45-Breakout-21The second iteration of the breakout with a Dual-USB-Serial-Converter (FT2232)
- Size
- 87 × 68 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 145
- Nets
- 84
- Pads
- 391
- Tracks, vias
- 1,030, 370
- Pours
- 6
- Routed
- Yes
- KiCad
- KiCad 6 (file 20211014)
- Created
- 7 May 2023
- Updated
- 21 Jul 2026
Overview
Modbus RJ45-Breakout is an open-source printed circuit board by the78mole, from the the78mole/ModBus-RJ45-Breakout-2 repository on GitHub. It is a 2-layer board of 87 × 68 mm with 145 parts on 84 nets, routed with 1,030 tracks and 370 vias.
It is built around the MAX485ED, 93LC46B/P and FT2232D, with the BSP250-VB among its other parts. Its parts include 37 capacitors, 37 resistors, 8 ICs, 8 connectors and 7 diodes. It belongs with the interfaces and adapters boards of this library.
Main components
4
MAX485ED
SOP-8-40℃~+85℃ 1 1 1mA 32 4.75V~5.25V 5Mbps Half-Duplex Transceiver ±8kV SOP-8 RS-485 / RS-422 ICs ROHSHTCRS-485 / RS-422 ICs
93LC46B/P
PDIP-80℃~+70℃ 1Kbit 2.5V~5.5V 2MHz 6ms SPI PDIP-8 EEPROM ROHSMicrochip TechnologyEEPROM
FT2232D
LQFP48Dual USB UART / FIFO I.C.FTDIUncategorised
BSP250-VB
SOT-223-55℃~+150℃ 1 P-Channel 1.8V 120pF 2.5W 23pF 35V 40mΩ@10V、48mΩ@4.5V 6.2A 9.8nC@4.5V 970pF P-Channel SOT-223 MOSFETs ROHSVBsemi ElecMOSFETs
README
README.mdModbus-RJ45-Breakout
A breakout board for Dual-ModBus-over-Twisted-Pair (RJ45) with isolated converters option
Here are some images of the first prototype, assembled with isolating RS485 transceivers. Echo already works, real testing on a ModBus will take place soon.
Production Files
This repository includes an automated workflow that generates production-ready files for PCB manufacturing and assembly. The workflow creates:
- Gerber Files - Ready for PCB manufacturer submission
- Drill Files - For via and hole drilling
- Schematic PDF - Complete circuit documentation
- Interactive BOM - HTML component placement guide
- 3D STEP Model - For mechanical design verification
- PCB Renders - Professional visualizations and assembly drawings
Using the Production Workflow
The workflow automatically runs on:
- Every push to
mainbranch - Every pull request
- Manual trigger via "Actions" tab
For Pull Requests: Download artifacts directly from the workflow run to review changes.
For Releases: Production files are automatically attached to GitHub releases with semantic versioning.
Manual Generation
To generate production files locally, ensure you have the required tools installed and run:
.github/scripts/generate-production-files.shFiles will be generated in the production/ directory.
Parts
145| Qty | Value | Footprint | References |
|---|---|---|---|
| 27 | Probe | TestPoint:TestPoint_Pad_D1.5mm | TP2, TP10, TP11, TP12, TP13, TP14, TP15, TP16, TP17, TP18, TP19, TP20, TP22, TP23, TP24, TP25 +11 |
| 21 | 100n | Capacitor_SMD:C_0603_1608Metric_Pad1.08x0.95mm_HandSolder | C3, C10, C11, C12, C14, C15, C18, C19, C21, C22, C24, C25, C28, C29, C35, C36 +5 |
| 10 | 27 | Resistor_SMD:R_0603_1608Metric_Pad0.98x0.95mm_HandSolder | R4, R6, R15, R17, R18, R21, R22, R23, R36, R37 |
| 8 | 10u | Capacitor_SMD:C_1206_3216Metric_Pad1.33x1.80mm_HandSolder | C13, C16, C17, C20, C23, C26, C27, C30 |
| 8 | 1K | Resistor_SMD:R_0603_1608Metric_Pad0.98x0.95mm_HandSolder | R3, R13, R19, R20, R24, R25, R29, R32 |
| 8 | np | Resistor_SMD:R_0603_1608Metric_Pad0.98x0.95mm_HandSolder | R2, R8, R10, R12, R14, R33, R34, R35 |
| 5 | 1n | Capacitor_SMD:C_1206_3216Metric_Pad1.33x1.80mm_HandSolder | C1, C31, C32, C33, C34 |
| 5 | Probe | TestPoint:TestPoint_THTPad_2.0x2.0mm_Drill1.0mm | TP1, TP6, TP28, TP34, TP35 |
| 4 | VCC_BR | Jumper:SolderJumper-2_P1.3mm_Open_TrianglePad1.0x1.5mm | JP3, JP4, JP6, JP7 |
| 4 | green | LED_SMD:LED_0603_1608Metric_Pad1.05x0.95mm_HandSolder | D1, D2, D3, D6 |
| 2 | 0 | Resistor_SMD:R_1206_3216Metric_Pad1.30x1.75mm_HandSolder | R1, R16 |
| 2 | 0 | Resistor_SMD:R_0603_1608Metric_Pad0.98x0.95mm_HandSolder | R30, R31 |
| 2 | 120 | Resistor_SMD:R_0603_1608Metric_Pad0.98x0.95mm_HandSolder | R5, R28 |
| 2 | 1K5 | Resistor_SMD:R_0603_1608Metric_Pad0.98x0.95mm_HandSolder | R7, R9 |
| 2 | 27p | Capacitor_SMD:C_0603_1608Metric_Pad1.08x0.95mm_HandSolder | C4, C5 |
| 2 | 500mA | Fuse:Fuse_1206_3216Metric_Pad1.42x1.75mm_HandSolder | F1, F2 |
| 2 | ADM2687E | Package_SO:SOIC-16W_7.5x12.8mm_P1.27mm | U4, U8 |
| 2 | GND_BR | Jumper:SolderJumper-2_P1.3mm_Open_TrianglePad1.0x1.5mm | JP5, JP8 |
| 2 | M4 | MountingHole:MountingHole_4.3mm_M4_DIN965 | H1, H2 |
| 2 | MAX485E | Package_SO:SO-8_3.9x4.9mm_P1.27mm | U3, U7 |
| 2 | RJ45_Weidmueller_2562920000 | the78mole:RJ45_Weidmüller_2562920000_Horizontal | J1, J2 |
| 2 | WAGO 2734-104 | the78mole:Dummy_0 | J7, J8 |
| 2 | WE-TVS-82400102 | Package_TO_SOT_SMD:SOT-23-6 | U2, U6 |
| 2 | yellow | LED_SMD:LED_0603_1608Metric_Pad1.05x0.95mm_HandSolder | D4, D5 |
| 1 | 10K | Resistor_SMD:R_0603_1608Metric_Pad0.98x0.95mm_HandSolder | R27 |
| 1 | 2K2 | Resistor_SMD:R_0603_1608Metric_Pad0.98x0.95mm_HandSolder | R26 |
| 1 | 2X04 | Connector_PinHeader_2.54mm:PinHeader_2x04_P2.54mm_Vertical_SMD | J6 |
| 1 | 470 | Resistor_SMD:R_0603_1608Metric_Pad0.98x0.95mm_HandSolder | R11 |
| 1 | 4u7 | Capacitor_SMD:C_1206_3216Metric_Pad1.33x1.80mm_HandSolder | C2 |
| 1 | 6MHz | Crystal:Crystal_SMD_HC49-SD_HandSoldering | Y1 |
| 1 | 93LC46B | Package_SO:SOIC-8_3.9x4.9mm_P1.27mm | U5 |
| 1 | APRA 449-440-45 | the78mole:Dummy_0 | DRA1 |
| 1 | BSP250 | Package_TO_SOT_SMD:SOT-223 | Q1 |
| 1 | BUS_1 | the78mole:Wago_734-164_1x04_P3.50mm_Horizontal | J4 |
| 1 | Bus_2 | the78mole:Wago_734-164_1x04_P3.50mm_Horizontal | J3 |
| 1 | FB | Resistor_SMD:R_0603_1608Metric_Pad0.98x0.95mm_HandSolder | L2 |
| 1 | FT2232D | Package_QFP:LQFP-48_7x7mm_P0.5mm | U1 |
| 1 | SH_GND_A | Jumper:SolderJumper-2_P1.3mm_Open_TrianglePad1.0x1.5mm | JP2 |
| 1 | SH_GND_B | Jumper:SolderJumper-2_P1.3mm_Open_TrianglePad1.0x1.5mm | JP1 |
| 1 | USB_B_Mini | the78mole:USB_Mini-B_Wuerth_65100516121_Horizontal | J5 |
| 1 | red | LED_SMD:LED_0603_1608Metric_Pad1.05x0.95mm_HandSolder | D7 |
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Questions
How big is the Modbus RJ45-Breakout PCB?
It measures 87 × 68 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Modbus RJ45-Breakout use?
145 parts, built around the MAX485ED, 93LC46B/P, FT2232D and BSP250-VB. 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 Modbus RJ45-Breakout KiCad files?
From the the78mole/ModBus-RJ45-Breakout-2 repository on GitHub, at the commit this page was made from: the board is Modbus-RJ45-Breakout.kicad_pcb and its schematic Modbus-RJ45-Breakout.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Modbus RJ45-Breakout design in my own project?
Its repository states no licence, so its author keeps all rights: ask the78mole before reusing the design.