I didn't quite understand your question. Are you requesting hardware help or firmware help?
SDA being bidirectional shouldn't be of any concern since I2C protocol is defined that way and as long as the slave follows I2C protocol you shouldn't have any issues connecting the two.
Please post the part number of the onsemiconductor device that you're trying to connect.
I am trying to program a hearing aids hybrid Ayre SA3291.For programming using programming cable CS44!My idea is to program the hearing aid without using cable.I think to use a wireless transceiver.The Transceivar should be a
Single-Chip Very Low Power RF .Power supply-1.3V!!! I can not find the right transceiver?Perhaps there is another method, but I can not think of it! So I share my idea on this forum and look forward ideas!