# I2C exception handling.

**URL:** <https://forum.sierrawireless.com/t/i2c-exception-handling/3145>\
**Category:** General wireless topics\
**Created:** [April 21, 2009, 11:25am UTC](https://forum.sierrawireless.com/t/i2c-exception-handling/3145 "2009-04-21T11:25:24Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Madouc](https://avatars.discourse-cdn.com/v4/letter/m/b782af/32.png) [@Madouc](https://forum.sierrawireless.com/u/Madouc)\
**Post date:** [April 21, 2009, 11:25am UTC](https://forum.sierrawireless.com/t/i2c-exception-handling/3145/1 "2009-04-21T11:25:24Z")

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could it be that there is NONE?  
could it be that the device (Q2686H in this case) silently restarts, leaving the I2C bus in an unusable state?

-edit-  
to clearify the problem a bit  
some traces from Target monitor

```auto
Trace	SYS	2	[knocker_addKnockNow] Knocking on 0
Trace	SYS	2	[sc_groupSend] sending action : 0
Trace	SYS	3	gpio: input 0 triggered
Trace 1	Unable to find the string of the remote trace in the file (ID = 34831)
Trace 1	Unable to find the string of the remote trace in the file (ID = 33768)
Trace	SYS	2	gpioRead 0x180C4404 Failed
Trace 1	Unable to find the string of the remote trace in the file (ID = 34831)
Trace 1	Unable to find the string of the remote trace in the file (ID = 33768)
Trace	SYS	2	gpioWrite 0x180C4404 Failed
```

and then it resets leaving the I2C bus in an unrecoverable state