rtbyte
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Re: RGB out ?

Mon Mar 12, 2012 11:49 pm

Is there a cheap way to connect raspberrypi to an RGB input ? There are tons of monitors, TVs and even car systems that only have RGB inputs, but on the market the only converters I see are RGB to RCA. I think there is one that do the opposite but it costs like 200EUR !!!

PS: I just looked and my TV has no RCA too and all HDMIs are used, but I have 2 RGBs free

Lynbarn
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Re: RGB out ?

Tue Mar 13, 2012 12:12 am

rtbyte said:


Is there a cheap way to connect raspberrypi to an RGB input ? There are tons of monitors, TVs and even car systems that only have RGB inputs, but on the market the only converters I see are RGB to RCA. I think there is one that do the opposite but it costs like 200EUR !!!

PS: I just looked and my TV has no RCA too and all HDMIs are used, but I have 2 RGBs free



No, but try unplugging something else from the HDMI - you can only use one input at a time!

rtbyte
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Re: RGB out ?

Tue Mar 13, 2012 12:26 am

Try doing that every time you need any of the devices and You can kiss your TV ports good bye  . Btw it was a just a example which is just in front of me.

The main problem is with all the devices which have neither RCA nor HDMI (as my car or my older monitors lol). The idea is that an RGB signal is easy convertible to almost everything and as I now found out RCA and HDMI are not

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Jessie
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Re: RGB out ?

Tue Mar 13, 2012 3:06 am

Then buy a surround reciver with a HDMI switch in it then, cause there isn't a cheap HDMI to RGB option out there.  Cheapest useable one I have seen is $37 USD on monoprice.

My last TV set had 1 HDMI 1 DVI and all the other lesser ports.  My newer set has 5 HDMI, 1 DVI, and all the other lesser ports.  Plus my Denon reciever has a 4 port HDMI switch on it.  My point?  Newer devices will have more ports.  How does this help you?  It dosn't, but the product can't be made for every possible video output option.  The foundation is aware that RGB is valueable to some people and plan on addressing it at some point, but that will be down the road and not right now.  I can tell you from exp that chips that generate RGB are not cheap, I usually use Anologue Devices chips and they run anywhere from $10 to $15 a peice (although the distributers could get a volume discount on them whereas I only buy 1 at a time.)  My point is that these chips are pricy probibly would cost the same as the Broadcom SOC being used on the R-Pi.

The other option for you and many others is to make a resistor ladder DAC and bit-bang the video out on the GPIO pins.  This would eat tons of CPU cycles I couldn't give you an exact estimate but when it is done on microcontrolers it typically eats up as much as 80% of the processor's time.

rtbyte
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Re: RGB out ?

Tue Mar 13, 2012 5:53 am

I should buy a $37 equipment for a $30 one ? I can't seem to get your logic !

And for a car multimedia system it is not feasible BY FAR

MotoBarsteward
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Re: RGB out ?

Tue Mar 13, 2012 9:09 am

http://www.js-technology.com/s.....product=42

It's £69 but I've used products from these people before. Although the boxes may look a bit Heath Robinson, the electronics inside is top-notch which excellent video quality.

mole125
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Re: RGB out ?

Tue Mar 13, 2012 9:48 am

rtbyte said:


I should buy a $37 equipment for a $30 one ? I can't seem to get your logic !

And for a car multimedia system it is not feasible BY FAR


The logic is to achieve what you are asking for, the price of the RPi is irrelevant here, whether $37 is worth achieving what you want to achieve is the only important question.

XAPBob
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Joined: Tue Jan 03, 2012 2:40 pm

Re: RGB out ?

Tue Mar 13, 2012 10:08 am

HDMI/Composite -> RGB convertor: £40ish

New screen: £more

Not buying an RPi: £saving

The device isn't actually designed as a media centre.  It just happens to make a rather good one IFF you have the other bits in your "bits bin"

dave j
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Re: RGB out ?

Tue Mar 13, 2012 12:13 pm

rtbyte said:


I should buy a $37 equipment for a $30 one ? I can't seem to get your logic !

And for a car multimedia system it is not feasible BY FAR


So buy a $37 device to use with one of your, presumably more expensive, other devices that also has HDMI out but no RGB out, then you can use and RPi with the freed up HDMI input.

The RPi is no different from lots of other new devices in having no RGB out and is no more deserving of your ire than they are.

citakis
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Re: RGB out ?

Wed Mar 14, 2012 1:52 pm

The problem with the lack of vga is not for personal use. Almost everyone has a new tv or an old tv at home (raspberry doesn"t have a problem to connect with a tv), I have a wide screen at my living room with four dvi inputs and on my desk I have a monitor with a hdmi input so there is no problem here.

The problem is that I want to buy a rpi as a present for my daughter but in her room there is an old lcd monitor with only a vga input. If I want to use it I have to spent the extra money for dvi->vga converter or buy a new monitor. But I am a parent and for my child I would do that.

Another problem is at the school that I teach, which unlike the school at cambridge that Eben visited for the rpi demonstration, my school does not have such new equipment. We have a class with 13 computers equipped with Pentium II or Pentium III processors. With my own expense I bought some extra memory for them and replaced windows 98 with puppy linux in order to make them useful again. My principal declined the request for new computers but he didn't say no to the idea of buying raspberry pi. So I believed I could buy some rpi and replace the old computers but the monitors I have are old (crt and lcd ) with only vga input. Of course with the extra expense of the converter I have to abort it until I find the extra money for new monitors

I don"t want to be misunderstood, I don"t blame anyone. I understand that you couldn"t satisfy every single need we have, but if there is any low cost solution even if it evolves some soldering or pcb manufacturing that could possibly save me and I believe many more.

rtbyte
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Re: RGB out ?

Thu Mar 15, 2012 2:21 am

@citakis Exactly !!! Somebody got my point at last !

In my case it's my car internal video system, my grand parents TV(s), my older monitors - so tons and TONS of displays and I have no way to use them. I don't wan't to use RPi for my TV. My TV is hooked to a giant nVidia video card with a 4 core CPU machine and 8GB of ram , so I don't care if RPi can be hooked to my newer displays . I care for a cheap way for my grand parent to be able to see pictures and famly videos and may be use skype and some browsing - so cheap mini computer hooked to a cheap old TV. But the suggesting I should by a $37 (in US so add %20 here in EU) + RPi is absolutely pointless coz I can buy ready to use devices for less. Why should I bother with RPi then ?:)

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Jessie
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Re: RGB out ?

Thu Mar 15, 2012 3:12 am

We totally understand your point.  And here is a solution, as stated in my above post buy a box that costs more than the R-Pi!  And like I said above as well the foundation is aware if the value of the VGA port to some people and they are working on a solution.


Why should I bother with RPi then ?:)


Don't, move along, that is one less person for me and the other 200,000+ pre-orders to fight with over a unit.  It should be blatently obvious to you by now that until there is a unit with RGB out of some type it is not going to work for you.  Thanks for waisting all our time.

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Jongoleur
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Re: RGB out ?

Thu Mar 15, 2012 7:37 am

@rtbyte:

I'm not trying to teach you to suck eggs, but a TV with "RGB" input would be a pretty funny TV if it didn't also have Composite video+audio input too. Are the TVs so old that they don't have SCART either?

I appreciate that your main concern is that you can't feed the Pi into your in-car system but for heavens sake! The Raspberry Pi is a personal computer to help develop programming skills.  That it has awesome media potential is a bonus. That it doesn't meet YOUR particular requirements is sad.  But there's no point turning up here, beating your gums about how it'll cost the same as the Pi extra to adapt it to your own peculiar requirements.

If the Pi is going to be too expensive with the additional gear, then do a bit of research and get yourself a media PC that'll run in your car and do the RGB out and come within your cost budget.  And buy your grandparents a decent TV.  If theirs is so old, then they're probably wrecking their health.
I'm just a bouncer, splatterers do it with more force.....

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