DART-SD410 Yocto UART
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DART-SD410 - UART
The default Linux release exposes two DART-SD410 UARTs. To show all the available UARTs use:
# ls /dev/ttyMSM* The output will be: /dev/ttyMSM0 /dev/ttyMSM1
- /dev/ttyMSM0 is used by serial console
- /dev/ttyMSM1 exposed as user UART on the J7 Connector.
To test the /dev/ttyMSM1 UART connect pins 2 & 3 (RX & TX) and 7 & 8 (CTS & RTS) on the J7 connector. Configure the UART to 115200 baud using rts-cts flow control
# stty -F /dev/ttyMSM1 -echo -onlcr 115200 crtscts
Start receive task in background:
# cat /dev/ttyMSM1 &
Send something to the port:
# echo "Serial Port Test" > /dev/ttyMSM1 The output will be # Serial Port Test The receiver printed out the message.
To stop the background receiver use
# fg Output: cat /dev/ttyMSM1 Press ctrl+c to exit
You can try the same scenario with pins 7 & 8 disconnected.
In this case the transmit buffer will get all the data send to /dev/ttyMSM1 and hold for handshake.
The data will be printed out as soon as the pins 7 & 8 will be connected.