The most common thing that effects i2c is the connection of cables or a bad cable it's self. Check for loose connection, bad pins or bad cable. Good luck.

@Athene , What could cause an EZB to lock up when sending i2C commands?

@Athene must be taking a break and offline.

@dave, replace the "e" at the end of her name with and "a"

OMG! Thanks Will. LOL!

@Athena What could cause an EZB to lock up when sending i2C commands?

There are a few things that could cause an EZB to lock up when sending i2C commands. One common issue is a bad or loose connection between the EZB and the device it is communicating with. Another possibility is that the device is not responding to the i2C commands correctly. It is also possible that there is a bug in the software or firmware that is causing the issue. If you are experiencing this problem, I recommend checking your connections and making sure that the device is responding correctly. If the problem persists, you can contact Synthiam support for further assistance.

hi averyone

you can turn the cable 180 degree. and plug it back in .

Found the culprit, one of the Arduino's wasn't responding, causing the EZ-B to freeze and kill the whole robot. Nasty but at least found the rootcause. I have tried a cabled EZ-B connection and a WIFI EZ-B connection, in both cases the EZ-B freezes. For now, I have commented out the I2C write command. Would have been nice if ARC just responded with an error/exception message instead of "hanging". Anyhow, it was not the ARC SW release.