2010-01-20 08:03:06     ADV7183B and EXT-BF5xx-VIDEO

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2010-01-20 08:03:06     ADV7183B and EXT-BF5xx-VIDEO

Harald Krapfenbauer (AUSTRIA)

Message: 84853   


I've tried the blackfin_cam and adv7183b drivers with our extender board and cm-bf561 core module as described in the docs, using ffmpeg.


*) Configuration via I2C is working, I can put the chip in power down mode.


*) Streaming works too, I can view a stream on the PC with VLC (ffmpeg runs on the board).


*) Added ADV7183B_GPIO_OE and ADV7183B_STRONG defines to adv header file


But I guess there is something wrong with the video format - attached is a beautiful screenshot... I already played with the DEFAULT_FORMAT define - the chip should output UYVY as the driver suggests - with no luck.


I thought this would be easy though the example is running on 561 EZKIT but obviously it's not. We've similar connections, except the syncs are not connected on our board. But that shouldn't matter, the driver only uses ITU656 information what I saw.


Do you have any hints for me?


Thanks, Harald






2010-01-20 13:40:01     Re: ADV7183B and EXT-BF5xx-VIDEO

Jean-Christian de Rivaz (SWITZERLAND)

Message: 84863   




There so many things that can happens in a custom board, especially when you have two PPI buses.


First check all the PPI signals with an oscilloscope proprely connected as close as possible to the BF561 chip. PPP clock issue are very common. Loading the clock with a resistor close to the BF561 have fixed some board I have worked on.


Secondly the ADV7183B output a image full of blue by default if there is not valid signal at his input. The is very noticiable on the PPI data. Try to disconnect and reconnect a source and see what happens to the data and to the streamed images. The frame rate should not vary. If the images are not streamed periodically, then you probably have a bus integrity issue.


The driver have been writed for a PAL image. Something could be wrong if you une an other format.


Finally, check that you use the right bits of data from the ADV7183B. The driver use the 8 bits mode and the ADV7183B output them on the signal P8 to P15 pins, not on the P0 to P7 pins ! I have made this mistake in my first board :-(


The frequency of the chip also play a role, but looking at your screenshot, I don't think that explain what you get.


Best Regards,






2010-01-21 04:06:53     Re: ADV7183B and EXT-BF5xx-VIDEO

Harald Krapfenbauer (AUSTRIA)

Message: 84931   


I forgot to say that this board is already running with in-house developed software - so I am sure the hardware design is ok.


Therefore, I was more searching for problems in the Linux driver...




2010-01-21 07:51:02     Re: ADV7183B and EXT-BF5xx-VIDEO

Jean-Christian de Rivaz (SWITZERLAND)

Message: 84938   


The driver has bee tested on at least 5 boards from what I known, so I am sure the soft is ok. :-)


If you have a working setup for the PPI registers and the ADV7183B registers, you can compare them with the values used on Linux. There is a /sys/kernel/debug/blackfin/ where you can find all the blackfin values. The ADV7183 values are in the setup part of the driver.