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by PR77
Sun Feb 14, 2016 2:42 pm
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 109523

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

I have put DPI dot_clk on oscilloscope no matter what I set the dot_clk frequency has never go below 25MHz. I think this is the reason why it has problem with small LCD. Are there any of you can change it? Hi Weetit, I had this issue when either hmdi_settings and/or the dpi_output_format was not co...
by PR77
Thu Feb 11, 2016 8:15 pm
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 109523

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

Hi all,

Any ideas with the Framebuffer issue? When I display the rgb_test.jpg I only see part of the image so it seems the physical screen resolution is not being handled by the OS. Hummm. This is where I am lost! :(
by PR77
Tue Feb 09, 2016 8:09 pm
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 109523

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

Quick update: Over and under scan aren't looking the most promising. I can get the top of the screen image aligned but the bottom is proving to be more difficult; no matter what I change the overscan_bottom to, it doesn't seem to change anything. Another thing I would like to get feedback on is the ...
by PR77
Mon Feb 08, 2016 6:22 pm
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 109523

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

Hi All, Since getting the DPI interface working with some nice 5 Inch LCDs I have subsequently tired some 4.3 Inch LCDs with a higher resolution. Furthermore, I am now running Raspbian Jessie and the DPI configurations don't seem to work anymore! Anyone else have issues with Jessie? I am keen to se...
by PR77
Mon Feb 08, 2016 10:02 am
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 109523

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

Hi All, Since getting the DPI interface working with some nice 5 Inch LCDs I have subsequently tired some 4.3 Inch LCDs with a higher resolution. Furthermore, I am now running Raspbian Jessie and the DPI configurations don't seem to work anymore! Anyone else have issues with Jessie? I am keen to see...
by PR77
Tue Mar 24, 2015 9:06 pm
Forum: Beginners
Topic: How can I install VMac for emulate Mac OS 7.5.5 on Raspberry
Replies: 8
Views: 4900

Re: How can I install VMac for emulate Mac OS 7.5.5 on Raspb

Hi All,

Seems a bit of time has gone by on this topic without any updates. I would be interested to know if anyone has managed to get mini vMac running on the Pi natively. I.e., not hosted.
by PR77
Wed Feb 18, 2015 9:27 pm
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 109523

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

Quick update... Pixel perfect success! With a half decent trigger setup and digging into the timings for the display I now have a pixel perfect display. I no longer have the 2 quirky pixels on the top of the screen and the frame buffer is correctly doing the text wrapping. I ditched the CVT and went...
by PR77
Wed Feb 11, 2015 10:31 am
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 109523

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

CVT only specifies a handful of resolutions, and 50 Hz is the slowest one. My screen gets by just fine in terms of wrapping without forcing a certain framebuffer resolution. I did use console-setup for a smaller font, though. Thanks. I will try the console-setup later in the week. I am also plannin...
by PR77
Tue Feb 10, 2015 10:01 pm
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 109523

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

Correct Colours.jpg Woo hoo! Finally I have the correct colours! :D :D :D The problem was the phasing of the V+H Sync signals. I do however have a couple of stray pixels on the very first row which I did not have before. Nevertheless I'm not too concerned about these just yet. I'm really happy the ...
by PR77
Sun Feb 08, 2015 10:15 pm
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 109523

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

thecodeman wrote:The display is 800x480 and the the clock is 30mhz .
spec for the display is here http://store.earthlcd.com/LB080WV3-B2
that picture is washed out some it really looks nice .
ken
Are you able to share your config.txt and DPI blob? I'm curious to know your cvt configuration. Thx!
by PR77
Sun Feb 08, 2015 7:37 pm
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 109523

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

thecodeman wrote:Yes that clock looks bad , But it still works .
If you run DE and PixClk through inverters it works very well .
Took us a while to get ours going .
And this is a 5v panel .
ken
pi8-1.JPG
pi8-2.JPG
Firstly, nice work! :) Secondly, what resolution is your screen and your D_CLK frequency? :)
by PR77
Fri Feb 06, 2015 11:05 pm
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 109523

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

Only the Pi? As in "nothing connected at all"? You are probing ID_SD, right? With nothing connected, and it still gives off weird traces? Try changing the pin mux to I2C and tossing something out there. It should happen on bootup as the Pi probes for an extension EEPROM, set your DSO to single-shot...
by PR77
Fri Feb 06, 2015 10:04 pm
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 109523

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

Ah. Consider: - Long ribbon cable to breadboard for the T-Cobbler - breadboard with metalic bus bars - wires to LCD Now that ugly scope trace makes sense - you are basically adding a lot of capacitance, filtering the high frequency signals. In your shoes, I'd try: - use a small protoboard that plug...
by PR77
Fri Feb 06, 2015 9:27 pm
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 109523

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

That trace looks awful. Again, I wish I knew what my working trace looked like. I see nothing wrong with config and pin mux. One more idea: What kind and length of cables are there between the Pi and the screen. I am running lots of 10 cm jumper wires to a breadboard to a breakout to a 30 cm FPC ex...
by PR77
Wed Feb 04, 2015 8:42 pm
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 109523

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

I am most interested in the first two or four GPIOs, because they are where the magic happens. The rest just colors things. A sinusoidal output on a Pi GPIO seems strange. Either you have way too much reactance on the bus, something resonant is connected there or there is a high impedance somewhere...
by PR77
Wed Feb 04, 2015 12:19 pm
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 109523

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

Do you have gpio_list installed? https://github.com/rewolff/bw_rpi_tools/tree/master/gpio If so, does it report ALT2 for the first 27 GPIOs when you execute it? How clear is the 31 MHz trace and what levels does it have? A photo might be nice if you can provide one. Also, the complete config.txt th...
by PR77
Fri Jan 30, 2015 8:25 pm
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 109523

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

Unlikely. All data for each individual pixel is transferred in parallel (this is why over 24 pins are needed), so screwed colors are not what you would expect from clock issues, much less almost exactly inverted color. My guess is like Gert's, that the display requires opposite polarity on the colo...
by PR77
Fri Jan 30, 2015 8:19 pm
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 109523

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

@ceteras, good suggestion. I will try this. As I don't have X installed it may take a little longer to test this as I need to figure out how to display a picture with it. I'm far from a Linux guru! cd /tmp wget http://1zelda.com/tv/pics/rgb_test.jpg fbi rgb_test.jpg You may need to get that with su...
by PR77
Fri Jan 30, 2015 5:37 am
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 109523

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

I see green were it should be red I see blue where it should be green I see white where it should be black. All signals need to be inverted? There maybe the possibility of a LCD colour look-up table but I am not sure if that is usable in this situation. I have to ask an expert at Pi headquarters. @...
by PR77
Thu Jan 29, 2015 8:39 pm
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 109523

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

Fat D, thanks for the blob that has helped me a lot. I can now see am image on my screen and after abut a day tweaking with the dpi_output_format I have the image correctly aligned to the physical screen layout. However! The screen does not seem to be displaying the RGB correctly and the colours are...
by PR77
Fri Jan 23, 2015 8:39 am
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 109523

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

Quick update for those following. Still no action on my LCD. In fact I seem to have taken several steps backwards and have no activity on the DPI. I now can't see the RGB signals jumping about. I am still using a SD Card with RISC OS (I only have a 2GB micro SD available) but I would _assume_ that i...
by PR77
Sat Jan 17, 2015 8:45 pm
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 109523

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

Gents, thanks for your feedback! Will find some time tomorrow to get stuck into it again. P.S., when modifying the DT DTS I removed the other nodes which are also using I2C Port 0; [email protected]_0_SDA_PIN { type = "internal"; number = <28>; }; [email protected]_0_SCL_PIN { type = "internal"; num...
by PR77
Mon Jan 12, 2015 11:07 pm
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 109523

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

Time for an update. I can't get the DPI working. On hand I only have a 2GB Micro SD Card so I'm using RISC OS, but reading older posts this shouldn't make a difference. Measuring the outputs signals with a CRO I can see the RGB signals jumping around (good sign) however the V+H Sync show after a res...
by PR77
Thu Jan 08, 2015 1:49 pm
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 109523

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

Brilliant! I will check this once I get a chance! Perhaps I will try and post a picture! :D From a quick look at those posts I'd say something like dpi_cvt 400 240 50 6 dpi_group=2 dpi_mode=87 would be a start. That's assuming the refresh rate for your screen is 50Hz and 15:9 ratio. You'll have to c...
by PR77
Thu Jan 08, 2015 9:31 am
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 109523

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

Hi, Thanks for your feedback. I did in fact check these posts however I don't quiet understand how with these settings set the DPI to display a resolution of 400x240. Am I missing something? Thanks! dom, My apologies - I forgot about that! Now that you have mentioned it, I do recall your posts a whi...

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