Dual Channel UART RS232-WAN Extension

This Plugin for the Andino X1, provides a DualChannel UART to the Raspberry Pi or the Arduino Controller. The WAN version has an internal connection for using a Lora WAN or 2G, 4G modem

Andino X1 - Dual Channel RS232 Extension

Overview

The Board based on the SPI Uart from NXP SC16IS752. The SPI Channel can be jumpered to the Raspberry Pi or the Arduino Controller. With the Arduino Controller time critical protocols can be implemented or a general pre processing of the data can be performed.

If the Jumper is closed the 2nd UARTs RxD is wired to the external screw terminal.

If the Jumper is open the 2nd UARTs RxD is wired to the internal connector.

External connectors

Andino X1 - Dual Channel RS232 Extension

Andino X1 - RS232 Connector Skrew Terminal

Internal connector

Andino X1 - RS232 WAN internal RS232

Installation on the Raspberry Pi

Install sc16is752 overlay from dts-file

wget https://github.com/andino-systems/Andino/raw/master/Andino-Common/Extensions/RS232/Raspberry/sc16is752-spi0.dts
wget https://github.com/andino-systems/Andino/raw/master/Andino-Common/Extensions/RS232/Raspberry/makedts.sh
chmod +x makedts.sh
./makedts

or download the dtbo file

wget https://github.com/andino-systems/Andino/raw/master/Andino-Common/Extensions/RS232/Raspberry/sc16is752-spi0.dtbo
sudo cp ./sc16is752-spi0.dtbo /boot/overlays/

Append this to the /boot/config.txt

sudo nano /boot/config.txt
dtparam=spi=on
dtoverlay=spi0-cs,cs0_pin=8,cs1_pin=12
dtoverlay=sc16is752-spi0,int_pin=7

Reboot. After that two new Devices are available /dev/ttySC0 and /dev/ttySC1

Test

sudo apt-get install minicom
sudo minicom --setup

select /dev/ttySC0 or /dev/ttySC1

Application examples

Useful links

Forum SC16IS752 (SC16IS7XX driver) Device Tree problem
Device Tree, Overlays and Parameters
List of Overlays

Author