usb driver problem

J. Landman Gay jacque at
Sat Jan 15 22:31:30 EST 2011

On 1/15/11 10:54 AM, Thomas McGrath III wrote:
> I now keep getting "file is not open for read" on the cu.usbmodem1a21
> and "eof" on the tty.usbmodem1a21
> What am I missing here?
> -- Tom McGrath III 3mcgrath at
> On Jan 15, 2011, at 11:18 AM, Thomas McGrath III wrote:
>> I am having trouble accessing an Arduino Uno attached to my
>> computer via USB.
>> The device driver shows up as "/dev/tty.usbmodem1a21"
>> I tried a simple open driver then read from driver then close
>> driver. But Livecode keeps crashing or worse my computer panics and
>> dies.

This came up in the support queue. Basically "open driver" is only for 
(real) serial devices. To open a usb device that is posing as a serial 
device (i.e., you have a usb/serial port adapter) then you should use 
"open file" instead. Treat the port just as you would a regular file.

There's no USB support per se, so if the device doesn't present itself 
as a serial port device it won't work.

The path you use when you open a serial port as a file is the same one 
you'd use in shell -- use the "/dev/tty.usbmodem1a21" path you 
mentioned. Also, see if you can talk to it in shell just as a test.

Jacqueline Landman Gay         |     jacque at
HyperActive Software           |

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