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