UART Devices¶
The UART interface provides TTL-level serial communication for devices that output raw UART signals. This is common on bare sensor modules, microcontroller boards, and some consumer devices.
Wiring¶
Connect the device to the UART 3-pin terminal block:
| Pin | Signal | Description |
|---|---|---|
| 1 | GND | Signal ground |
| 2 | RX | Device transmit → HALSER receive |
| 3 | TX | HALSER transmit → device receive |
Voltage Selection¶
The UART output voltage can be set to 3.3 V or 5 V using a jumper on the board.
- 3.3 V — For 3.3 V logic devices (most modern modules)
- 5 V — For 5 V logic devices (Arduino Uno, classic sensors)
The UART input is 5 V tolerant regardless of the jumper setting.
Compatible Devices¶
The UART interface is suitable for:
- Victron VE.Direct — Raw UART at 19200 bit/s. Connect the VE.Direct cable's TX, RX, and GND wires directly to the UART terminal block. Set the jumper to 3.3 V.
- Serial sensors — Sensors with UART I/O requiring galvanic isolation
- Microcontroller-to-microcontroller — Direct communication with Arduino, ESP32, or other MCU boards when isolation is required