I have an OV5642 ArduCam with the 8-pin interface. This module has a RAM buffer and a chip to translate from SPI & I2C into the MIPI/DVP used by the camera module.
I have found https://www.arducam.com/downloads/shields/ArduCAM_Mini_5MP_Camera_Shield_Hardware_Application_Note.pdf and it documents the registers, but I suspect it is not complete. I can not get any identifying info for the chip because it is under a heat sink (which can get really hot if you aren't operating in power-saving mode)
One thing not explained by that document is register 7 which is written to in one of the example sketches: https://github.com/ArduCAM/Arduino/blob/3577fbd1b5a9f4afbe9923718fa0f265d671dc3a/ArduCAM/examples/mini/ArduCAM_Mini_5MP_OV5640_Plus_Functions/ArduCAM_Mini_5MP_OV5640_Plus_Functions.ino#L52
Another is https://github.com/ArduCAM/Arduino/blob/3577fbd1b5a9f4afbe9923718fa0f265d671dc3a/ArduCAM/examples/mini/ArduCAM_Mini_5MP_OV5640_Plus_Functions/ArduCAM_Mini_5MP_OV5640_Plus_Functions.ino which is represents a bunch of register writes to configure resolutions and formats. (used by the
wrSensorRegs16_8() method at https://github.com/ArduCAM/Arduino/blob/3577fbd1b5a9f4afbe9923718fa0f265d671dc3a/ArduCAM/ArduCAM.cpp#L2997 )
sensor_reg tuples reference registers like 0x3103 and 0x401d, which are not documented in the PDF from arducam.com.
Where can I find documentation that would let me understand these register writes?