UART

Introduction

iCore-1684XQ supports 3 UART devices:

The RS485 interfaces diagram of iCore-1684XQ board is as follows:


Debug

Users can use different host's USB-to-serial adapters to send and
receive data to the serial port of the development board according to
different interfaces. For example, the debugging steps of RS485 are as
follows:

(1) Connecting the hardware

Connect the RS485B-A, RS485B-B and GND of the development board to the
A, B and GND pins of the host serial adapter (USB to 485 to serial
port module) respectively.

(2) Open the serial terminal of the host

Open kermit in the terminal and set the baud rate:

   $ sudo kermit
   C-Kermit> set line /dev/ttyUSB0
   C-Kermit> set speed 9600
   C-Kermit> set flow-control none
   C-Kermit> connect

/dev/ttyUSB0 is the device file of the USB-to-serial adapter

(3) Send data

The device file for RS485 is "/dev/ttyS2". Run the following commands
on the device:

   sudo -s
   stty -F /dev/ttyS2 9600 -echo
   echo firefly RS485 test... > /dev/ttyS2

The serial terminal in the host can receive the string "firefly RS485
test..."

(4) Receive data

First run the following command on the device:

   sudo -s
   cat /dev/ttyS2

Then enter the string "Firefly RS485 test..." in the serial terminal
of the host, and the same string can be seen on the device side.