ET-C14
Auto-Direction RS-485 Board
RS-485 with automatic direction — just TX and RX
AED 19.00
Out of stockOverview
RS-485 with automatic direction — just TX and RX
The ET-C14 is built around the MAX13487E — half-duplex RS-485, AutoDirection (driver enabled by TX data), 500kbps, ±15kV ESD, 1/4 unit load. It connects over Just TX/RX — no DE/RE pin to manage; works with any UART (Arduino SoftwareSerial, Modbus libraries) and is powered from 5V.
Designed in Dubai by ElectroTrical — the full schematic, BOM and design notes are published below.
Good for
- Modbus RTU with any UART
- Long sensor cables
- Industrial meters and VFDs
Key features
What makes it different
Transceiver
MAX13487E: half-duplex RS-485, AutoDirection (driver enabled by TX data), 500kbps, ±15kV ESD, 1/4 unit load
Interface
Just TX/RX — no DE/RE pin to manage; works with any UART, Arduino SoftwareSerial, Modbus libraries
Supply
5V
Open documentation
Schematic, BOM and layout notes published for every board.
Breadboard friendly
Standard 2.54 mm pitch and M2.5 mounting holes.
Specifications
Technical specifications
| Transceiver | MAX13487E: half-duplex RS-485, AutoDirection (driver enabled by TX data), 500kbps, ±15kV ESD, 1/4 unit load |
|---|---|
| Interface | Just TX/RX — no DE/RE pin to manage; works with any UART, Arduino SoftwareSerial, Modbus libraries |
| Supply | 5V |
| Size | 25.4 × 17.8 mm |
|---|---|
| Mounting | 2 mounting holes (M2.5) |
| Connectors | 4-pin 2.54 mm header |
| Main IC | MAX13487EESA+T (LCSC C18347) |
| Revision | Rev A |
| JP1 (default Open) | Bridge for 120Ω termination |
|---|
Performance
Speed
Pinout
Pin map and connections
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | VCC | Power | 5V only (4.75–5.25V) |
| 2 | GND | Ground | Ground |
| 3 | RX | UART | → host RX |
| 4 | TX | UART | Host TX → |
Mechanical
Dimensions and what's in the box
In the box
- 1 × ET-C14 Auto-Direction RS-485 Board (assembled)
- 1 × 4-pin 2.54 mm male header, unsoldered
Getting started
- Wire the header: VCC, GND, RX, TX
Compare
Which RS-485 board?
| Auto-Direction RS-485 Board (this board)This board | ET-C01 RS-485 Transceiver | ET-C10 USB-C to RS-485 Adapter | |
|---|---|---|---|
| What it does | RS-485 with automatic direction — just TX and RX | Half-duplex RS-485 for Modbus and long UART runs, 3.3 V | Modbus RTU from your PC over USB-C |
| Interface | Just TX/RX — no DE/RE pin to manage; works with… | UART RX/TX + DE/RE direction pins, 3.3V logic | — |
| Best for | Modbus RTU with any UART | Modbus RTU sensors and meters | Modbus RTU from a laptop |
| Price | 19 AED | 9 AED | 28 AED |
Downloads
Documents and design files
Need a custom version of this board?
Different connector, size or sensor? We design and build custom variants.