I am working on a project involving cameras using a Zynq FPGA on a Digilent Zybo board. I can successfully get a response from an OV7670 by configuring it via SCCB. Even without configuration the OV7670 provides a PCLK and drives the data pins as long as I provide it an appropriate XCLK signal. I have recently bought an Arducam OV5640 module. The documentation that I have read so far about this module suggests that I can still use 3.3V logic. I get no response from this module when providing a 12-25MHz XCLK signal. Can someone point me in the right direction and make me aware of what I may be doing wrong? Is it really 3.3V logic or should it be less? Is there some power-up sequence that I am not aware of that I should be doing differently than the OV7670?
Any help will be much appreciated. I am really stuck and it is well known that Omnivisions documentation is far from complete.
Best Answer
Sensor default output:
After power up OV5640 sensor will not have any output signals. There are several registers (refer to the datasheet) that are responsible for enabling pad outputs. Thus, the registers must be configured before getting any output signals from the sensor.
Potential I2C Communication problem with ZC702 board:
I had communication problem with OV5640 sensor. After investigation, it appeared that there is a slave address conflict between the image sensor and HDMI controller that is on the ZC702 board. The solution was to disable channel 1 of the I2C mux, and allow only channel 5 that is routed to the FMC connector.
It is worth mentioning the OV7670, that I would expect to have a slave address conflict due to the I2C port expander that is also on the board and is on the channel 3 of the I2C mux. Thus, it must be disabled to allow only addressing the image sensor.