# Setting baud of USB to UART converter.



## caesius (May 31, 2011)

My University's department of EE has built these nifty USB to JTAG converters that can also do USB to UART. I'm trying to use the UART at the moment but am having some trouble setting the speed. The converter uses an FTDI chip and shows up as /dev/ttyU0 and /dev/ttyU1 (I have no idea why both).

Everything works fine if I open kermit and set these options:

```
set line /dev/ttyU1
set speed 38400
set carrier-watch off
```

But when I tried setting the speed from the command line it didn't work:
`% sudo stty -f /dev/ttyU1 speed 38400`

Then I found this article which explained how to set the speed by twiddling with the /dev/ttyU1.init device file, but that method required a bunch of other options too.

Am I blind or is there little about this in the serial communications section of the handbook? How do I just set the speed of the serial connection? I've tried:
`% sudo stty -f /dev/ttyU1.init speed 38400`
`% sudo stty -f /dev/ttyU1.lock speed 38400`
With no luck.

Cheers.


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## aragon (Jun 1, 2011)

Normally the speed is set by the process opening the terminal device.  What is accessing it, and can't the speed be set in its configuration?


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## caesius (Jun 1, 2011)

aragon said:
			
		

> Normally the speed is set by the process opening the terminal device.  What is accessing it, and can't the speed be set in its configuration?



I am the configuration. I'm currently setting the speed using the termios structure in C. But I want to be able to fiddle around with the device (it's an integrated image sensor and controller) and it would be helpful to be able to set the baud with the command line (at the moment I'm using kermit just to set the baud).


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