Dexter Serial Peripherals

Serial devices, such as TTL serial adapters, ModBus adapters, or other devices with a serial interface like the OpenMV camera can be connected to Dexter's USB A connector, found just under the CAT5 connector on the MicroZed board.

To verify the connection, you will need to SSH in or connect via the USB console cable.

Once you are at the command prompt on Dexter, with the device disconnected type the following commands (bolded in the sample session below):

ls /dev/co*
/dev/console
ls /dev/ttyUSB*

Now, plug in the device and wait a few moments, then enter those same commands again. In this case, I've plugged in a simple USB - TTL adapter based on the CP2102 chip. Look for the difference:

ls /dev/co*
/dev/console
ls /dev/ttyUSB*
/dev/ttyUSB0

As you can see, the new device is there at /dev/ttyUSB0

To test it's operation, you can even use the command line to send and receive data. e.g. Here is a sample session for an Arduino device programmed to respond with some binary data and a few analog port readings in response to a "?". You can find the code for that here: https://gist.github.com/JamesNewton/8b994528ff3ce69e60bbb67c40954cd2

stty -F /dev/ttyUSB0 ospeed 57600 ispeed 57600 raw
echo -ne '?' > /dev/ttyUSB0
cat -v < /dev/ttyUSB0

In that session, the following showed up at the console: <10000000000000,470,419,423,389,362,343>^M

You can have a two way conversation via typing in data and seeing the result via:

stty -F /dev/ttyUSB0 ospeed 57600 ispeed 57600 raw
cat /dev/ttyUSB0 & cat > /dev/ttyUSB0

Press Ctrl+Z to exit.