Strange I2C problem (and solution)

[timmers]

If the "other end" of the I2C bus is running off 3.3v, then the SDA and SCK will be pulled down to 3.3 + 0.6 ish volts. through the devices protection diodes to Vcc.

Just a thought!

Timmers.

[brid0030]

Thanks Timmers, but everything is running off the same 5.6V. I'm still a bit mystified, but my best guess is that the regulator cannot put out enough current (I'm using an onboard regulator from another component, which is "supposed" to be able to support a microprocessor).