WMP + NC I2C problems?

[dieterm57]

Hey, I am trying to build my own bicopter and started with what I thought to be a good multiwii starting setup.
At first I tested the WMP only and it worked pretty well. I did not have to consider putting external pullup resistors or desoldering internal pullups as it worked out of the box.
But I encountered serious problems with the NC connected in passthrough mode.
Sometimes I get I2C errors rising like hell and then there is this kind of strange 'reset' of the I2C every few seconds and the NC not working at all.
Currently I use 2K resistance from 3.3V to pullup the lines, but it does not work. At 5V the same error occurs.
Any help is appreciated

Thanks


Image of the setup

http://www.youtube.com/watch?v=wLYKQNz_-XY
Video of the MultiWiiConfig

[dieterm57]

Hm, currently I do not know why I tried to 'save' one resistor and share it for both lines to create 2K, but this was definately one problem (since I connected SCL to SDA with just 1K in between ^^). Must have been the heat of the moment lol.

Nevertheless the I2C bus becomes unstable every some seconds. I measured a voltage frop of about .5V of the SCL and SDA lines. When the connection seems to work I can measure 4.7V and just moments later it breaks down to just 4.2V.

Has someone got a hint?
Thanks

[dieterm57]

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