AXIOMTEK SCM188 User Manual page 31

3.5.1.5 Serial Port
The SCM188 with SCB184 supports the serial port with different mode & baud rates. This
section explains how to test the switch mode and test.
Configuration for Serial Ports
The SCM188 with SCB184 supports below several serial ports, these ports provide varies
protocols, please refer to following list for the supported list.
⚫ /dev/ttymxc0
◼ RS232
⚫ /dev/ttymxc2
◼ RS232
◼ RS485
To exercise the serial port for /dev/ttymxc2, there are several modes must be configured by
the switch, the following command demonstrates the test though all protocols, the default
mode is RS232.
⚫ Enable serial port switch
sh-5.1# cd /sys/class/gpio
sh-5.1# echo 480 > export
sh-5.1# echo 481 > export
sh-5.1# echo out > gpio480/direction
sh-5.1# echo out > gpio481/direction
⚫
Switch serial port to RS232
sh-5.1# echo 1 > gpio480/value
sh-5.1# echo 0 > gpio481/value
⚫ Switch serial port to RS485
sh-5.1# echo 0 > gpio480/value
sh-5.1# echo 1 > gpio481/value
SCM188 BSP User Guide
SCM188 NXP i.MX 8M Plus ARM-based SMARC Module
27