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I'd like some suggestions about how to fix garbled serial output from a device connected on /dev/ttyACM0. Lately I've been working on a development project making use of TI's MSP430 microcontroller (specifically the eZ430-RF2560). Over on this thread you can see we've been testing some code and have found that the output of the microcontroller over serial is garbled. The btstack provides simple counter test program. When we run the program and look at the serial port output using PuTTY on Windows 7 we see:

rfcomm_send_internal cid 117 doesn't exist!
BTstack counter 26230
rfcomm_send_internal cid 117 doesn't exist!
BTstack counter 26231

However if we connect from various Ubuntu clients we get something like:

BTacn 0 
BTacn 002BTacn 0 
BTcct 04BTtacoe 5BTacun 

My current belief is that this is because the device is being detected by cdc_acm as a generic USB ACM device. Another thread about a similar microcontroller suggests that the device should use a specific usb serial driver. We've verified that the module is compiled on our system and did a "modprobe ti_usb_3410_5052" but this had no effect on cdc_acm. Here is the relevant section of the kernel's debug log:

[ 2735.092987] usb 2-1.2: new full speed USB device number 5 using ehci_hcd
[ 2735.213655] cdc_acm 2-1.2:1.0: This device cannot do calls on its own. It is not a modem.
[ 2735.213669] cdc_acm 2-1.2:1.0: No union descriptor, testing for castrated device
[ 2735.213720] cdc_acm 2-1.2:1.0: ttyACM0: USB ACM device
[ 2745.241996] generic-usb 0003:0451:F432.0003: usb_submit_urb(ctrl) failed
[ 2745.242023] generic-usb 0003:0451:F432.0003: timeout initializing reports
[ 2745.242401] generic-usb 0003:0451:F432.0003: hiddev0,hidraw0: USB HID v1.01 Device [Texas Instruments Texas Instruments MSP-FET430UIF] on           usb-0000:00:1d.0-1.2/input1

So, in summary, we'd like to figure out how to properly connect to this device. Also of use may be the appropriate place to file a bug report.

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Bug report filed: – speciousfool Mar 12 '12 at 10:45
Could not reproduce this bug on another 11.10 installation. Will rebuild machine and retest. – speciousfool Mar 15 '12 at 9:26
up vote 1 down vote accepted

Garbling was due to loading improperly formatted binary which was mangling strings.

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