Cheap(ish) portable monitor

Now I know that the Pi is supposed to be cheap but you keep finding extra things to buy.

I was wondering about a screen, between 7" and 10", as found in loads of tablets.

Doesn't even have to be a touch screen - just something small and portable, which could for instance be used in a car or camper van.

Some fora suggest screens designed for reversing cameras, and using an RCA connector - which would suit an automotive use.

Has anyone gone down this route, and can tell me any good deals and options to avoid?

TIA

Dave R

I went for the 3.5" reversing camera screen. It's not large enough for anything other than retro-computer emulation. 7" is the minimum screen size you should consider and even then you're probably looking at a

I've been finding lots of LCD monitors, either working or in need of some n ew electrolytics in the power supply, The small ones are bigger than you specify, but are free if you find them. They do all seem to have DVI input , aand DVI is generally available from an HDMI port,

Unless they've all been scrapped, an older and cheap laptop would make a go od terminal.

Someone mentioned digital frames. I thought I'd seen one that did display video, but I may have been misinterpreting. It may have meant that you can load it with a video file and play it, not the same as connecting as a mon itor.

The problem is that while lots offer LCD screens, old laptops, that $10 GPS I got earlier this month, those digital frames, they aren't some standalon e monitor. You couldn't pull an LCD screen out of an old laptop and have a monitor, it needs the circuitry in the monitor, hence the notion of using a laptop as a terminal to the Pi.

If portable DVD players are showing up used, the display might be a actual NTSC monitor, though you'd have to figure out hwo to add an input jack. I have no idea why I'm thinking they would be monitors rather than some integ ral unit.

In the old days you could find small CRT monitors, but I suspect most of th em have disappeared by now.

Michael

A lot of portable DVD players ship with a composite video input, and they can be picked up second hand for next to bugger all.

The composite video input is often a 3.5mm jack (or in some cases 2.5mm) rather than a phono plug, but adaptors are easy to come by or make if the unit doesn't already come with a cable.

You could even rip out the DVD drive and replace it with the pi for a self contained unit.

-Paul

Be even nicer if you could access the DVD drive from the Pi :-)

Cheers

Dave R

That's not likely to happen. As mentioned in another thread, A lot of DVD players use drives that are intended for the purpose, not standard IDE or S ATA drives. My DVD recorder that I found in a recycling bin has a standard drive, it seems like early on there were some players that used standard d rives, but the ones I've looked at more recently are not standard. They do n't even have much electronics on the drive.

Of course, even if they were IDE drives, you'd need something to interface them to USB in order to connect to the Pi.

I just got a Kobo Mini yesterday, an ebookreader. I of course immediately did some searches, it turns out to run Linux. But someone wrote about using it as a terminal, so I guess that's an option, it is small. Though by the time you get something to interface it to the Pi, and the ebookreader (I p aid $40 Canadian, half the usual price), other options look better.

And since the Kobo Mini uses an e-ink display, the update is slow, you can see it happening, so using it as a terminal would be like hooking up a Tele type machine to the Pi.

Maybe we're looking at this in reverse. My TV set runs LInux, instead of a dding a card, get it to be a complete Linux system. Though, likely not eno ugh hardware to be useful.

Michael

You don't have to find scrapped equipment always. Sometimes people give away monitors just because they don't need them. I got two off of Freecycle. They do both need repair although one didn't tell me that. That one turned out to be easy to fix, a bit of the plastic power button had broken off inside and wouldn't push on the tiny momentary switch. Turns out that once you turn it on, if you turn it off by removing power externally it comes back on automatically when power is reapplied! So I have a fully working monitor. The other one comes on for a moment and then the screen cuts off again. I haven't figured out what that one needs.

I guess this wouldn't be suitable for rPi since they have VGA inputs. I expect an old TV would do the job better.

Respectfully pointing out the word 'portable' in the OP.

Also the dimensions of 7" - 10".

The two requirements combined rule out any CRT and most (if not all) LCD TVS and PC monitors.

Cheers

Dave R

I didn't say anything about CRT. Yeah, if he really wants to stick to

He being me, of course, and yes I do.

Just assume, for the moment, that I have a number of PC monitors, at least two of which have DVI, and a number of HDMI TVs.

In that case I wouldn't be needing another (old, outdated and probably broken) monitor or TV.

However if I was considering a portable and/or automotive application for the Pi I might want a small portable monitor not larger than 10".

I might even ask a question about this on a Pi news group :-)

Cheers

Dave R

Actually, I thought that original post of yours was kind of vague. Clearly you wanted something cheap, but whether you wanted something small for a s pecific reason or whether you were looking because you were also looking fo r cheap wasn't clear.

The cheapness of the Pi was based on using the family tv set with it. I ca n see why that's an issue, and then if you have to find a monitor, if it's not used or garbage the price goes up considerably (even if an LCD monitor can be had new for way less than a CRT monitor decades back).

So I interpreted your post as "so what can I get that's cheap, and hopefull y smaller". A 15" LCD lying on the sidewalk isn't small, but it is cheap, if you were just using the Pi at home it's an option. Even for some embedd ed uses, I can start to see all kinds of possibilities with a $35 Pi and LC D monitors of any size that can now be found in the garbage. Projects that weren't practical before, because the hardware was expense, and cheap hard ware was too bulky.

There aren't many options for small and cheap. And "cheap" becomes relativ e. I'm not going to find a portable DVD player in the garbage, I'm not eve n seeing them much at garage sales, which may mean buying new, and then the price goes up.

I wouldn't waste that $10 TomTom GPS receiver on use as a monitor, I'm not likely to find another one that cheap. On the other hand, it does run Linu x, so perhaps it can be redefined, the main issue being whether one can get I/O through the USB port.

Unless you buy new, it will take digging to find a really small and cheap m onitor for the Pi. Unless something is very popular, it won't be cheap, an d it won't be available used.

Michael

You may be able to find a reversing monitor that'd accept composite input

Really? Because I went to a car boot sale yesterday, and after I'd bought one for £2 I found at least another 5 (but obviosly only needed one of them)

Really? Garbage and Garage Sale are your only options for finding second hand kit? There are hundreds of the buggers on ebay for naff all, I've not checked craigs list, freecycle or my local free-ads paper but I'm willing to bet there's more than one on there.

I don't know what world you live in, but I spent an hour yesterday literally tripping over cheap, small displays which take composite inputs - and I wasn't even really trying.

-Paul