Hello, me again, sorry. Probably worng forum but don't know where else to go now. Using ExpanderPi with ServoPi and it works most of the time using a direct <20cm connection (5V side of the bus), but falls over with anything longer (e.g. a bit of veroboard sat next to the Pi), despite signal looking fine on a scope. In practice, this means I can't add anything else to the bus.
Also, I would like to a P82B715 I2C extender to talk to remote components, but when I plug the chip in it knock the bus voltage down to ~1V and destroys the signal. I have a feeling this might be down to the chip lowering overall impedance below the threshold for the ExpanderPi's voltage converter, but not sure. If so, how could I extend the bus?
Full thread here, with 'scope traces:
Any suggestions appreciated.