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by HeBus
Wed Sep 24, 2014 4:23 pm
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 115494

Re: Gert's VGA add-on for the B+

rgb_order can be one of: DPI_RGB_ORDER_RGB, DPI_RGB_ORDER_BGR, DPI_RGB_ORDER_GRB, DPI_RGB_ORDER_BRG, output_format is the config.txt setting dpi_output_format DPI_OUTPUT_FORMAT_9BIT_666, DPI_OUTPUT_FORMAT_16BIT_565_CFG1, DPI_OUTPUT_FORMAT_16BIT_565_CFG2, DPI_OUTPUT_FORMAT_16BIT_565_CFG3, DPI_OUTPUT...
by HeBus
Wed Sep 24, 2014 3:00 pm
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 115494

Re: Gert's VGA add-on for the B+

Thanks dom for giving a look at this. I guess it's the output_enable_polarity (which is set to active low currently). I need to think of a way of exposing these options. dt-blob.bin is one possibility extending hdmi_timings is another extending dpi_output_format is another I suspect the whole struct...
by HeBus
Wed Sep 24, 2014 2:07 pm
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 115494

Re: Gert's VGA add-on for the B+

Thank you for trying it!!!! This is excellent news! Inverting DE is not a big deal, and it may be possible to invert it through some I/O setting. I do hope that it is possible to invert it by software. It seems crazy to think that broadcom put this DPI feature into the chip and actually picked up t...
by HeBus
Wed Sep 24, 2014 2:00 pm
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 115494

Re: Gert's VGA add-on for the B+

Still no luck. I had also tried active_low, now added pull_up... No change. "polarity" may only be active for GPIO and do nothing once pin have been dedicated to dpi. I will try to find the kernel code that reads the device tree file and program pins, to see if I find a hint...
by HeBus
Wed Sep 24, 2014 1:44 pm
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 115494

Re: Gert's VGA add-on for the B+

Now I did : no change :-(
I had already seen those lines in dt-blob-dpi.dts, but I suspect "polarity=active_high" is only a valid option for input signals.
by HeBus
Wed Sep 24, 2014 12:12 pm
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 115494

Re: Gert's VGA add-on for the B+

Hi, This is my 1st post in this forum, so first : a BIG THANKS to the whole Raspberry Pi team and foundation for their GREAT work. And a special mention to Gert and Dom who unveiled details about this DPI interface. This is exactly what I needed to play with something I have been eager to try for so...

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