I am having the same trouble! Today is the first time using the BlinkM and the I2C port and EZB keeps browning out. What can we be doing wrong? I even tried to power the BlinkM from another source and still the same thing. I don't have any trouble until I run the BlinkM script. Unlike you though I lose my blinking blue light on the board and can't get it back until it's unplugged from power and then plugged back in. Will keep working on solving the problem but just wanted you to know I'm having trouble here too.

@Herr Ball I tried the very same thing as well! " I even tried to power the BlinkM from another source and still the same thing." Have you tried testing with a volt meter on the SDA and SCL ? I am wondering if the 5 volts tested is normal or not! Also across the two , powered down, on the ohm scale.

What other peripherals are connected to the EZ-B when you are testing the BlinkM?

A few issues I have had with I2C which may guide you in the right direction (they may not though) are;

Brownouts caused by the HD servos, moving the servos on to their own supply solved this. The issue was more on the servos than I2C but it did cause some funny behaviour which is why I am mentioning it.

Connections being reversed on the SDA and SCL. This locked up the EZ-B was unresponsive until power cycling.

Loose connections/poor wiring also has caused some strange behaviour, then the SDA and SCL aren't connected or the connection drops somehow (usually through low quality wiring that open circuits) it would lock up the EZ-B and power cycling was needed.

I'd say check the connections on the SDA and SCL to the BlinkM. Check the resistance of the wiring and make sure it's low and doesn't fluctuate too much when the wiring is moved.

Also check the Vcc and Ground. The BlinkM has points on it for an external source if needed or just run Vcc and Ground from another 5V source with more current available.

I can confirm that my BlinkM has run fine plugged directly in to the I2C port, it's also worked fine when daisy chained on my LCD display. No pull up resistors are used on my I2C lines.

@DJ no other peripherals or BlinkM ..bare board! ...and sometimes it fails on the first command I2C script run and other times the third or fourth run. I am thinking there may be an issue with the board (out of warranty) If someone could check the voltages individually on the SDA and SCL to compare with my readings It will confirm or deny my suspects.

@irobot58

My I2C 5 volt pin is putting out the 5 volts it should. The voltage from the SDA and SCL pins are putting out 5 volts to ground also. I reread the manual and still can't figure what is going on. I have not tried any other I2C devices as I have none.

Just wanted to let you know about the voltages you ask for. Back to pulling out some more hair, something there is not a lot of anymore ... LOL.

Oh and DJ, I am not running anything else at the time of the brownout also.

@Herr Ball

Thanks for the update! Very interesting that there are two boards doing the same thing under the same circumstances. Thanks for testing the SDA and SCL leads . I hope this info helps DJ think of any further ideas to correct this issue... I am fearing the worst as it might be an internal board issue .....we''ll see what DJ says PS ....I can empathize about the pulling of hair! I think I might pull armpit hair instead! LOL

Please read the top paragraph. There seems to be a issue with the I2C. I assume it affects us too?

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