Possible VGA monitor workaround?

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by msb » Sat Jun 09, 2012 9:57 pm
It strikes me that many schools will only be stocked with older VGA input monitors in their classrooms, yet the Raspberry Pi only features Composite and HDMI output sockets.

I can see two possible workarounds - one is to buy a Composite to VGA adapter box, around £15+ on eBay at present.

The other is to spend a bit less on a USB Video Grabber. That way you can connect the Composite output to the grabber, plug the grabber into a PC's USB port, then display the resulting image on your VGA monitor using VLC Media Player (or similar) set to full screen display with the grabber selected as the source. That way you spend a bit less and have a video grabber available for other purposes.

If this form of PC piggy-backing makes sense, then it might be worth buying a USB to Micro USB cable for your Raspberry Pi's power supply instead of the more expensive three pin power pack.

Just a thought anyway.
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by JeremyF » Sat Jun 09, 2012 10:35 pm
cheaped confirmed converters that cost the same as any of the things you mentioned:
http://elinux.org/RPi_VerifiedPeriphera ... rter_boxes

And you can still get the full resolution of monitor, unlike a composite converter.
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by Trevor » Sun Jun 24, 2012 12:23 pm
Why not get one of these?

http://www.hdfury.com/products/hdfuryii ... g-started/

They work perfectly on my Pi, and Apple TV
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by mahjongg » Sun Jun 24, 2012 12:45 pm
If its not listed in the wiki, it should
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by poing » Sun Jun 24, 2012 12:54 pm
mahjongg wrote:If its not listed in the wiki, it should


That thing costs $400!
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by mahjongg » Sun Jun 24, 2012 1:04 pm
Oh, forget it then. :x
for half that (or less) you can buy a second hand DVI-D monitor, the only disadvantage being that a DVI-D monitor does not support sound, so you need a set of speakerboxes.
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by razoreye » Tue Jul 10, 2012 2:16 pm
VGA to HDMI cable on Amazon - http://www.amazon.co.uk/gp/product/B004 ... 01_s00_i00

£3.69 including FREE shipping from Amazong and works fine.
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by itimpi » Tue Jul 10, 2012 2:23 pm
razoreye wrote:VGA to HDMI cable on Amazon - http://www.amazon.co.uk/gp/product/B004 ... 01_s00_i00

£3.69 including FREE shipping from Amazong and works fine.

That cable will NOT work with the Pi. It is a passive cable that is only suitable for devices that generate analog signals on the HDMI output, and the Pi does not. The giveaway is when it mentions it will not work with PCs or Laptops. You need an active cable that does digital to analog conversion and the cheapest cable anyone has mentioned was about £15.
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by LuaPie » Tue Jul 10, 2012 2:52 pm
This sounds expensive, almost as much as the cheaper version of the Raspberry Pi itself!

I think schools with VGA monitors will just have to avoid the Raspberry Pi.

But this isn't a problem, because the Raspberry Pi was intended for the home environment for parents who didn't want to let their children loose on the home PC. It wasn't meant for schools anyway, it was meant for the home.
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by Mortimer » Tue Jul 10, 2012 3:07 pm
Why? If they already have a VGA monitor that they want to use, what alternative to a £30 Raspberry Pi, plus a £15 HDMI-VGA adapter is there?
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by PaulCheffus » Tue Jul 10, 2012 3:26 pm
LuaPie wrote:But this isn't a problem, because the Raspberry Pi was intended for the home environment for parents who didn't want to let their children loose on the home PC. It wasn't meant for schools anyway, it was meant for the home.


Hi

Was it, that isn't the impression I have.

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by varesa » Fri Jul 13, 2012 1:17 pm
I got the impression, that this was targeted to people (children), who can't afford a better computer or other platform, to learn programming on (like developping countries). The decision to not have VGA, is strange considering this aspect. It is more likely for them to have/get a old cheap CRT with VGA, than a new flat tv with hdmi. Of course there is the composite interface...
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by LuaPie » Sun Jul 15, 2012 3:37 pm
Mortimer wrote:what alternative to a £30 Raspberry Pi, plus a £15 HDMI-VGA adapter is there?

The computers they already have? Schools upgrade their computers every 3 years or so. My one kept the old computers, didn't throw them away and let us dismantle and tinker with them.

varesa wrote:The decision to not have VGA, is strange considering this aspect. It is more likely for them to have/get a old cheap CRT with VGA, than a new flat tv with hdmi. Of course there is the composite interface...

Yes, that's ironic isn't it. They omitted VGA to keep costs down and keep the RaPi affordable and yet HDMI TV's is something that only rich people have. Whoops.
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by FX4 » Fri Aug 03, 2012 2:20 pm
You guys are going after the wrong output:
http://www.monoprice.com/products/produ ... 1&format=2
32.00
Although I think the developers got it right. I have one VGA monitor left that still functions correctly. The others, four or five in the last two years have been tossed as problems developed. I do run them into the ground. So I think the existence of recycling VGA monitors is going to be somewhat rare. You can by an HDMI monitor for under $70.00 new so I think this is hardly an issue.
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by Mortimer » Fri Aug 03, 2012 3:30 pm
Eh!? FX4, why would anyone prefer to convert the composite video to VGA, rather than HDMI to VGA? Especially as some of the HDMI converters are a fraction of the price of the converter you have linked to.
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by FX4 » Fri Aug 03, 2012 4:05 pm
Why would anybody want to down convert HD video to VGA? You don't.
That being said the OP was looking for a cost effective solution to a theoretical problem that I don't believe will exist except in rare cases. I provided one. No one else has.

If you want me to agree that the designers made an error, I won't because I don't think they did. This thing is designed to plug into new monitors and televisions with a backwards compatibility nod to composite video. I think that is plenty for most situations.
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by Mortimer » Fri Aug 03, 2012 5:30 pm
I agree, but HDMI to VGA is far better than Composite to VGA. We have some large Samsung Full HD TVs at the office that will take a VGA signal at 1920x1080, not much of a downgrade there. It's far better than the max of 720x576 you'd get using composite.
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by FX4 » Fri Aug 03, 2012 6:01 pm
Yes but those VGA connectors were provided for backwards compatibility for older HTPCs. This years televisions don't have a VGA connector. Samsung just swapped out my Plasma and the replacement has no VGA. Exact same model three years newer.
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by PaulCheffus » Fri Aug 03, 2012 7:43 pm
FX4 wrote:Yes but those VGA connectors were provided for backwards compatibility for older HTPCs. This years televisions don't have a VGA connector. Samsung just swapped out my Plasma and the replacement has no VGA. Exact same model three years newer.


Hi

Yet my Panasonic bought this year still has a VGA socket.

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by Joe Schmoe » Fri Aug 03, 2012 7:51 pm
Somebody seems to have missed the point here.

Of course, if you have a HDMI input capable TV, you won't bother converting the signal to VGA; you'll (obviously) just use an HDMI cable to connect it to the HDMI input.

The issue has always been "What if I don't have an HDTV?" What if I have a (or a whole bunch of) old VGA monitor(s) laying around and I want to use it (them) with my Pi. In that case, the only (and apparently, pretty good) option is to buy (at additional expense, alas) an HDMI -> VGA converter box.
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by Mortimer » Fri Aug 03, 2012 8:36 pm
I agree Joe. I may have misunderstood but I thought FX4 was advocating the use of a composite to VGA converter instead of HDMI to VGA.
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by mahjongg » Fri Aug 03, 2012 9:07 pm
I think that many people fail to understand one very important fact:
The PI's "HDMI" port can also be used to connect to DVI-D monitors! Look at the back of even older flatscreens, (the ones that are dumped at charity stores), and you will see a second white connector, next to the blue VGA one. Very often this is a DVI-D connector, and you can connect such monitors to the pi simply by choosing a different interface cable!

There are a few pitfalls you must be aware of though:

1) Some of these DVI connectors are actually VGA connectors in disguise, they resemble real DVI-D connectors, but are not! These have a few less connection holes, and are marked DVI-A.
2) Unlike read HDMI DVI-D monitors won't provide sound, so you must use the analog sound output.

If you are unsure about what a DVI-A connector looks like, simply read the DVI wikipedia article, but basically if there are not at least two 3x3 areas of connection holes, then its not a useable DVI connector for a PI.

All the DVI connectors in the next picture will work with a PI, except the bottom one.
Image

So look at the back of your old "VGA" monitor and you might find it will work with the PI after all!
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by FX4 » Fri Aug 03, 2012 10:11 pm
Mortimer wrote:I agree Joe. I may have misunderstood but I thought FX4 was advocating the use of a composite to VGA converter instead of HDMI to VGA.

I don't think advocate is the correct word. I provided a cost effective solution, nothing more.
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by Mortimer » Fri Aug 03, 2012 10:16 pm
But as I pointed out the product you linked to was several times the amount some RPi users are paying for an HDMI to VGA converter, so arguably not cost as cost effective and technically inferior.
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by FX4 » Fri Aug 03, 2012 10:17 pm
mahjongg wrote:I think that many people fail to understand one very important fact:
The PI's "HDMI" port can also be used to connect to DVI-D monitors! Look at the back of even older flatscreens, (the ones that are dumped at charity stores), and you will see a second white connector, next to the blue VGA one. Very often this is a DVI-D connector, and you can connect such monitors to the pi simply by choosing a different interface cable!

There are a few pitfalls you must be aware of though:

1) Some of these DVI connectors are actually VGA connectors in disguise, they resemble real DVI-D connectors, but are not! These have a few less connection holes, and are marked DVI-A.
2) Unlike read HDMI DVI-D monitors won't provide sound, so you must use the analog sound output.

If you are unsure about what a DVI-A connector looks like, simply read the DVI wikipedia article, but basically if there are not at least two 3x3 areas of connection holes, then its not a useable DVI connector for a PI.

All the DVI connectors in the next picture will work with a PI, except the bottom one.
Image

So look at the back of your old "VGA" monitor and you might find it will work with the PI after all!

Out of all my VGA monitors I have owned exactly one with this functionality. Actually it is the one that is still working. I might give this a whirl for grins.
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