Problem on Interfacing SCCB Slave with I2C Master

Projects Networking, Protocols, and Devices
1

Hi There,

Problem Statement:
When we connect OV5640 camera with I2C master (not SCCB) it should not send an ACK on the 9th clock cycle and, therefore, should not work with our I2C master. However, when we connect our I2C master to the OV5640 camera, we are observing an ACK.

Help:
We reviewed the documentation but could not find explicit confirmation that the camera should send an ACK. Can someone please explain what may be the issue?

Thanks,
Vhigneshwaran.

2

Try probing the SDA line with an oscilloscope to confirm whether the OV5640 is truly pulling it low.

3

Thanks for the reply @ahsrabrifat

We checked with Logic Analyzer able see 0 at 9th clock pulse but as per SCCB datasheet it will send both 0 ,1 or x. So, couldn't conclude it will send only 0 for ACK bit.

Screenshot 2025-03-26 173042
Screenshot 2025-03-26 1730421073×707 99.5 KB

if anyone from OmniVision Technical support or anyone have proof for -SCCB Slave will send only 0 for ack and 1 for nack and it will not send x. We are able to conclude this is a proper acknowledgement.