I am building a gimbal and passing I2C through sliprings. Right now I have 1.6Vpp spikes at about ~32kHz on the i2c bus. (The spikes are harmonics from motors which are driven at 16~17kHz).
The i2c bus is at 400kHz, so I believe I need a high pass filter to block anything below maybe 100kHz? How else would I clean the i2c bus?
I added an CR filter (cap in series, tried 1nF, 10nF and 100nF with 2k, 1k and 800R pull up) but the sensor wont even start with this modification.
I also added ferrites on both ends of the cable to kill any higher frequency spikes.
P.s.: it works perfectly if I pass the wires outside the sliprings with motors on and through the sliprings with the motors off.