Re: OV7620 image sensor interface with FPGA headache

From: Georgi Beloev (gbH8SPAM_at_beloev.net)
Date: 11/16/04 

Date: Tue, 16 Nov 2004 10:19:03 -0800

Dalle,

According to the data*** the SCCB serial interface is enabled only if pin
SBB = 0.

HTH,
-- Georgi

"dalle002" <dwmunandar@yahoo.com> wrote in message
news:85ba9fbbc8922505cf3632db7049cf71@localhost.talkaboutelectronicequipment.com...
> Hello,
>
> I am trying to use the OV7620 to get a RGB digital output using FPGA
> Spartan 2 (PEGASUS by Digilent)with the intention to display the image on
> a regular monitor. The default output of the OV7620 is YCrCb, interlace
> scan, and 16-bit. While what I need is an RGB, progressive scan, and 8-bit
> output.
>
> I tried so hard to write into the OV7620 register to get the output I want
> but of no avail. First I thought it might be because the FPGA I/O operates
> at 3.3v but the Omnivision data sheets mention that the minimum high input
> to the I2C bus is only 3v, so it should not be a problem.
>
> The SDA and SCL output from the FPGA into the camera pins observed using
> an oscilloscope shows no problem; it produced signals as specified in the
> OmniVision data sheets. But when connected to the camera, there is no
> acknowledge signal, only a small pull down signal whenever acknowledge is
> expected (only about .1v down from 3.3v high) which I assume is nothing.
> The first thing I want to do is to write register 13h with the value 21h
> using the slave and write ID 84h. If this were a success write, the PCLK
> should get doubled up to 26-27MHz, shouldn't it? But I don't see any
> effect on the PCLK frequency (still at 13MHz) after my register write
> sequences.
>
> Any help greatly will be appreciated. I have been trying this and that for
> weeks without progress. Is my sensor burned or I miss something? The
> analog output is still working right now, so I assume the chip is still
> normal. I'll be glad to give more detail as needed if someone can offer
> any help.
>
> Thanks in advance!
>
> Dalle
>