Author Topic: DigiCDC Randomly will Disappear from USB ls (Ubuntu 14.04)  (Read 5686 times)

TeamCirle

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DigiCDC Randomly will Disappear from USB ls (Ubuntu 14.04)
« on: December 11, 2015, 09:14:57 am »
Hello Digistump community.  This is my first post here so please forgive me if I just jump right in. 

We are are Medical Device Incubator who is using the Digispark as a USB device for simple footpedal control and have a bug we cannot find a root cause for.  Any help would be much appreciated   :D

We are using the DigiCDC library to re-initialize the device as a serial device which is working fine.  The issue is this; randomly it will drop off of the USB device list and will no longer be recognized by the OS (Ubuntu 14.04).  Even when the OS and computer system is powered down (but not disconnected from power) the USB device will still not be recognized.  Only after power is completely disconnected from the motherboard or the Digispark completely removed will the state be corrected and the OS once again able to initialize the device as USB/Serial.

This seems to be a timing or a power cycle issue or a combination of both.  The device will be recognized 2 times by the OS: Once as a standard USB device, then will drop into a 'limbo' state for 1-2 seconds , then, secondly as a serial device.  This action assigns 2 device IDs on the same BUS (which it should) and presumably dumps the first ID when it re-initializes as a serial device.  Every so often on startup or over time (several hours), the device status will be "lost" by the OS and never recovered.  Only a complete power drain of the system will allow the digispark to correct. 

Has anyone seen or heard of this instance before?  We have not been able to consistently recreate the issue and therefor have not been able to identify a root cause.  Any hint as to how we may be able to avoid this 'limbo' state would be much appreciated.  Thank you.


Best Regards,
Carlos Velasquez

TeamCirle

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Re: DigiCDC Randomly will Disappear from USB ls (Ubuntu 14.04)
« Reply #1 on: December 14, 2015, 07:06:21 am »
Thank you for the response Ralf.  This does shed some light on why over time we have seen Random disconnects.  I need to look for a very small form device, such as the digispark, that has USB hardware... or design one. 

Do you have any quick suggestions for a "plug-and-play" option with the USB connection/pins that is similar in size to the digispark?

Thank you again.  Cheers!