2010-03-25 12:56:46 why my bf531 can't get right picture?
macgrady tracy (CHINA)
Message: 87695
hello,every one,
There is a question puzzing me for a long time
i am use bfin531 and ov7670 coms senser to capture picture
i am sure the ov7670 sensor is OK, and when i use the testing mode of ov7670 i can get the correct picture
but when i try to get capture a pict of my own, the pict is black, most of the pict is black!!!!
my question is :
what is the correct of BF531's PPI I/O volt? 3.3v? 2.8v? 2.5v? or when the input volt is 2.2v, blackfin can recognize the I/O volt?
any one who can help me?
thanks!!!
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2010-03-25 21:54:14 Re: why my bf531 can't get right picture?
macgrady tracy (CHINA)
Message: 87703
ps:
i means the picture is dark ....
The blackfin PPI port read the 2.2V is "0" or "1"
Blackfin can support OV sensor?
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2010-03-26 05:14:56 Re: why my bf531 can't get right picture?
Michael Hennerich (GERMANY)
Message: 87733 > The blackfin PPI port read the 2.2V is "0" or "1"
This depends on VDDext. For VDDext = 3.3V it may read 1 on the PPI pins, but not sure it will also work on the PPICLK since VIHCLKINmin = 2.2V @ VDDextmax = 3.6Volt.
> Blackfin can support OV sensor?
You have several choices:
1) Increase OV Sensor IO-Voltage.
2) Reduce Blackfin VDDext
3) Use level shifters
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2010-04-01 05:05:16 Re: why my bf531 can't get right picture?
macgrady tracy (CHINA)
Message: 87972
thanks for you replay!
I have resolved this problem,
the reson of the picture dark is that the I2C(on platform of OV we call it SCCB) not been set correct!
thanks!!!