A simple 46mmx22.5mm module to route power and differential signals (RS-485) over RJ-45.
This project is also described in detail on Hackaday.io
It can be purchased as a kit from Tindie
This project is certified open hardware:
μDiff provides an easy way to reliably transfer power and a digital signal over a long-distance using an inexpensive RJ-45 cable.
It uses RS-485 differential signaling and 802.3af Power-over-Ethernet pinouts to achieve this. It can accept an input voltage between 6.5V-12V, and provides outputs of 5V and 3.3V. All signals and voltages can be accessed through a 10-pin header.
Current is limited to 1A. Beware of current limitations on the RJ-45 cable, it's typically ~350mA for an AWG26 shielded wire.
- Form factor 46mm x 22.5mm
- Lead-free, RoHS compliant
- Stackable with 4xM2 holes (1x grounded)
- Open Source Hardware under CC BY-SA 4.0
- Easy to source off-the-shelf through-hole components
- On-board (SMD 0603, 0805) capacitors, resistors, and diodes
- Solder bridge jumpers to enable fail-safe biasing, termination, grounding.
See images for more views.
| Quantity | Item and Description | Datasheet |
|---|---|---|
| 1 | RJ45 Connector | Assmann-RJ45-connector.pdf |
| 1 | 10-pin (2x5) 2.54mm male of female header | |
| 1 | 3-pin (1x3) 2.54mm male or female header |
See datasheets
The schematic is available here
This PCB was designed with Kicad v6.0 from the debian buster-backports repository.
I take no responsibility for any problems that may occur with your use of this PCB or design files. Create and use at your own risk.
μDiff: 10mbps over 1km on a single pair of wires © 2021~ by Alexander Williams is licensed under CC BY-SA 4.0 (Attribution-ShareAlike 4.0 International).