Can't send command ending with \r\n

[huzeifa]

Hi,

I am trying to send a command ending with \r\n , however it doesn't work.

my command: grabserial -d /dev/ttyUSB0 -b 2000000 -c adc\r

Some troubleshooting notes: I print the output of the command variable from line 681 of the grabserial code

if command:
            command += u"\n"
            print(command, end='')
            sd.write(command.encode("utf8"))
            sd.flush()

my output: adcr

It seems the \r character is not recognized

My temporary fix: add \r character together with \n character on line 681 to

if command:
            command += u"\r\n"
            sd.write(command.encode("utf8"))
            sd.flush()

Kindly advise if there are any other solutions for this

[tbird20d]

Very sorry about the very slow response. The problem is that the shell is not sending the \r as part of the argument.

You should be able to do this: grabserial -d /dev/ttyUSB0 -b 2000000 -c $'adc\r'

The extra $'...' should work in bash, and may work in other shells. It causes the shell to treat argument as a string to be literally printed. If you are calling this from a shell script, you can check which shell the script uses, and adjust that, if needed.

Or, this should work in most shell scripts: grabserial -d /dev/ttyUSB0 -b 2000000 -c $(printf 'adc\r')

Sorry again that this took me so long to get to. Ultimately, this is not an issue with grabserial, but with the calling environment, so I'm closing this.