Strange thing, my FPGA HDMI output cannot work with cheap chinese HDMI Extender

I bought HDMI extender over optical fiber for $125, from Alibaba.
HDMI Extender works well when Source is my laptop, but when source is my FPGA board,there is a problem.
I enabled TMDS, HPD, DDC, 5+, ground as in Hamsterwork's project , it doesnot works,I dont know why? Who had the same situation ? What to do ?
Alibaba seller know nothing about this, but they always tell me they manufacturer, and cannot help me, i think just reseller sit there, and there no technical support.
Reply to
abirov
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On Saturday, September 22, 2018 at 11:09:02 AM UTC-4, snipped-for-privacy@gmail.com wrot e:
FPGA board,there is a problem.
oesnot works,I dont know why? Who had the same situation ? What to do ?
facturer, and cannot help me, i think just reseller sit there, and there no technical support.
Yeah, you got that right! I've written to Ali and eBay vendors for more in fo on a product and the response is nearly always that the info is in the l isting... even when it is not. The vendors are probably like what we in th e US call "fulfillment centers". All they do is post the listings and ship the products.
A couple of times I've returned items explaining that they don't work right in some way and the vendor has asked for details to feedback to the factor y, but I think this was more so they could get a refund. In one case it wa s a laptop battery that was slightly oversized so it wouldn't fit properly into the laptop without forcing. At $50 I expected them to ask me to retur n it, but no, they just wanted details so they could get their refund from the factory.
Rick C.
Reply to
gnuarm.deletethisbit
On Saturday, September 22, 2018 at 11:09:02 AM UTC-4, snipped-for-privacy@gmail.com wrot e:
FPGA board,there is a problem.
oesnot works,I dont know why? Who had the same situation ? What to do ?
facturer, and cannot help me, i think just reseller sit there, and there no technical support.
I meant to ask, does your FPGA work with the target without the extender? I assume you've checked this. If so, I'd say ask for a refund and try to f ind a name brand extender even if it's three times the price. If your FPGA design works with this then the cause of the problem is obvious.
Rick C.
Reply to
gnuarm.deletethisbit
It might not support EDID, or might not safely transmit it over a long distance. Result is that the source can't detect what resolution to send.
You can either disable EDID in your project, or use an EDID emulator:
formatting link
(no idea if that particular one is any good) - with those, there's a way to 'train' them where you plug in the display directly and teach it the EDID, which the emulator replays when it's at the far end of the extender and the EDID can't be read.
Alternatively just send a fixed resolution like 640x480 without trying to detect what the far end wants.
Theo
Reply to
Theo Markettos
Thank you guys, especially thanx to Theo Markettos! in 480P it works.
I want it work on 1080p, could someone help to find it ?
Reply to
abirov
Thank you guys, especially thanx to Theo Markettos! in 480P it works.
I want it work on 1080p, could someone help to find VHDL code for DDC ?
Reply to
abirov
So just try sending 1080p without trying to probe the EDID?
If you need timings, 'cvt' is a handy tool to generate standard modes: (you can look up what each column means)
$ cvt 1920 1080 # 1920x1080 59.96 Hz (CVT 2.07M9) hsync: 67.16 kHz; pclk: 173.00 MHz Modeline "1920x1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync
Theo
Reply to
Theo Markettos
Cannot transmit 1080p but with 150MHZ, cannot generate 1080p with 173MHZ HDMI
Reply to
abirov
Who can explain me how to make 480P . because i fergot how i did and lost code ?
Reply to
abirov

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