USB-4SERIAL is Industrial grade -45+85C Open Source Hardware USB2.0 High speed USB to Four RS232 Serial ports + shared RS485 port

USB-4SERIAL is and Industrial grade -45+85C, Open Source Hardware USB-C type connector USB2.0 High speed to Four RS232 level or TTL level Serial ports. Port4 can be multiplexed between RS232 and RS485 current loop.

You can connect as many USB-4SERIAL as USB ports you have on your computer, this allow easy scaling when you need more than 4 Serial ports.

First Serial port has also RTS/CTS control, the other three are just Tx/Rx pairs.

The RS485 current loop Serial port is shared with RS232 Serial port4 and is jumper selectable what functionality to have RS232 or RS485.

For link to embedded board Four connectors with TTL levels are available.

The baudrate can be up to 12Mbps (400Kbps on the RS232 levels DB9 connectors due to IC driver limitation)

New useful parts for OLinuXino OSHW Linux computers, soldering tool and new components in stock


USB-RS485 is USB to RS485 converter and can be used with any computer with USB including OLinuXino.

A20-OLinuXino-MICRO, A64-OLinuXino, A13-OLinuXino, A33-OLinuXino, iMX233-OLinuXino have Audio input, for these boards we got very compact and flexible PC-MIC-3.5MM


For these who deal with tiny SMT parts we got stackable X*Y smt SMT-BOX-25x32x22 with spring loaded cap:


SLD-SPONGE is soldering tip cleaning sponge:


SLD-STAND is metal stand for soldering irons with place for soldering sponge:


CONNECTOR-GX16-4 is robust connector for panel mounting and can connect up to 220V/20A:


WIRE-CLIP-300F is female connector at one end which easy connects to boards with headers and sprint loaded contact at the other end. If you make signal analyzer with FPGA boards these clip wire connectors are very handy to attach to existing boards:


ALUMINUM-HEATSINK-TO-220 is low cost heatsink for TO-220 devices like voltage regulators and transistors:




iMX233-OLinuXino-MAXI talks through RS485 device via web interface


RS-485 is serial communication standard widely used for industrial applications.

MOD-RS485-ISO is optically isolated interface which adds RS485 communication possibility for all boards with UEXT connector.

To add RS485 to OLinuXino download the code from GitHub

and build it then copy mod-rs485-iso.php to the web server directory to may control MOD-RS485-IO via the web page.



MOD-RS485-ISO is 3000V isolated RS232 to RS485/RS422 full duplex converter based on ISO35T integrated circuit from Texas Instrument. This module is perfect for industrial applications and transmission of data in highly noisy industrial environments.

Works with all our boards with UEXT connector.



We just complete MOD-RS485-ISO galvanically isolated RS485 to UEXT module which allow all our development boards with UEXT connector to interface RS485 products, our old MOD-RS485 module was without galvanic insulation but as RS485 is used a lot in industrial and noisy environment we decided to release isolated version too.

The preliminary schematic of MOD-RD485-ISO is here:


note that after the prototyping this schematic may have changes, we add PIC16F1503 microcontroller to handle the UEXT communication and addressing by I2C.

Just learned today that Ken Segler is working on RS485 project with DuinoMite and implements MODBUS protocol by DuinoMite and MOD-RS485, for this purpose he implements 9 bit UART configuration.

For those who have not spoted yet PIC16F1503 is cool small new microcontroller from Microchip which cost USD 0.80 in small quatities!

It have 2K Flash and 12 GPIOs, 4 PWMs, ADC, DAC (5bit) and configurable logic for the ports!

We decided to put this PIC to all our new UEXT boards just to handle the I2C addressing and to allow many different modules to connect to UEXT bus without interferences.

PIC-H1503 is small header board we designed to may play with PIC16F1503 and USB-PWR is small module which powers BreadBoard bus through USB with selectable 3.3V-5V


both USB-PWR and PIC-H1503 board will be ready for sale in March.

USB-PWR will cost EUR 1.95

PIC-H1503 will cost EUR 1.95