chde
Posts: 16
Joined: Tue May 08, 2012 8:17 am

Car Rearview Screens

Sat Aug 18, 2012 7:25 pm

TRYING to work with a budget of £0 is difficult, I've spent about £18 so far :')

Anyway, I found two car rearview screens on Amazon which I think would be interesting to use with the Pi, using the yellow RCA lead.

However, I'm not sure what kind of quality I can expect from this, plus, I don't actually intend to use the Pi in a car, so I'm assuming that the power to the screens will be provided via cigarette lighter slot.. but I'm not sure.

Any advice please?

Here are the models:

http://www.amazon.co.uk/HDE%C2%AE-3-5-T ... 1&sr=1-134

http://www.amazon.co.uk/Engiveaway%C2%A ... 2&sr=1-357

JeremyF
Posts: 515
Joined: Wed Jan 25, 2012 9:06 pm
Contact: Website

Re: Car Rearview Screens

Sat Aug 18, 2012 7:34 pm

1. Fairly bad quality, most are less than 640x480 so fitting a desktop environment will be a challenge. (Display an image or a line of text, probably, though)
2. No power supply included, you need to hook up your own 12V (which could be 8 AAs in theory, although there's probably a better solution)
{sig} Setup: Original version Raspberry Pi (B, rev1, 256MB), Dell 2001FP monitor (1600x1200), 8GB Class 4 SD Card with Raspbian and XBMC, DD-WRT wireless bridge

User avatar
joan
Posts: 14763
Joined: Thu Jul 05, 2012 5:09 pm
Location: UK

Re: Car Rearview Screens

Sat Aug 18, 2012 8:46 pm

I bought one of these http://www.ebay.co.uk/itm/110854011256?

I use one of several 12 volt wall warts I had to supply power.

Remember these are video only, no sound.

Perfectly OK for videos. Unusable as a 80x25 character terminal. I do use it with lxterminal with a 26 point font. This gives a usable 24x8 display. Cheaper than an LCD!

samscribbler.py
Posts: 4
Joined: Mon Aug 20, 2012 8:33 pm

Re: Car Rearview Screens

Wed Aug 22, 2012 2:32 am

I use a 7 inch headrest monitor with my Pi (originally as part of a dual-screen DVD player set, but sold separately on eBay) that has the same yellow RCA lead. A bit bigger, yes, but the principle is still the same, and I've had no problems with it whatsoever.

Unless the monitor requires some weird, proprietary connector for a power source (which it looks like it doesn't), you should be okay simply using a universal adapter. They're a dime a dozen, and you can probably "borrow" one from another device in your house.

Quality definitely takes a hit in downsizing, but it isn't THAT bad. Really. Simply come to grips with the fact that a standard desktop environment isn't going to work on a screen that small and you'll be fine. Just be sure to optimize the resolution settings by editing /boot/config.txt, first.

phillrymer
Posts: 12
Joined: Mon Aug 13, 2012 12:55 am

Re: Car Rearview Screens

Thu Aug 23, 2012 1:26 am

chde wrote:TRYING to work with a budget of £0 is difficult, I've spent about £18 so far :')

Anyway, I found two car rearview screens on Amazon which I think would be interesting to use with the Pi, using the yellow RCA lead.

However, I'm not sure what kind of quality I can expect from this, plus, I don't actually intend to use the Pi in a car, so I'm assuming that the power to the screens will be provided via cigarette lighter slot.. but I'm not sure.

Any advice please?
ive used the same screen from ebay £22.08, but mine came with a 12v mains adapter ive now swapped that for a 6800ma battery pack £20 on ebay works great i connect the screen with a male to male connector cuts down wire length it worked straight out the box no problem, ive now got wifi working and a kindle battery pack made a neat unit
Here are the models:

http://www.amazon.co.uk/HDE%C2%AE-3-5-T ... 1&sr=1-134

http://www.amazon.co.uk/Engiveaway%C2%A ... 2&sr=1-357

phillrymer
Posts: 12
Joined: Mon Aug 13, 2012 12:55 am

Re: Car Rearview Screens

Thu Aug 23, 2012 1:33 am

Ive used the same screen bought from ebay £22 with mains adapter (now changed for6800Mah battery pack £20 ebay ive also got kindle battery to run pi wifi working and wireless keyboard and mouse worksed straight from the box ive also used a male to male connector for the screen to cut down on cable length ive had no problem with LXDE or XMBC running

toxibunny
Posts: 1382
Joined: Thu Aug 18, 2011 9:21 pm

Re: Car Rearview Screens

Tue Aug 28, 2012 4:57 pm

Have a search around youtube for raspberry pi stuff, I'm sure I've seen a couple of people using them. Quality looks pretty good considering the low res.
note: I may or may not know what I'm talking about...

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psergiu
Posts: 223
Joined: Mon Nov 07, 2011 8:36 am
Location: TX, U.S.A. (was: RO, E.U.)
Contact: Website

Re: Car Rearview Screens

Mon Sep 17, 2012 8:07 am

I have a 3.5" 16:9 aspect ratio "RearView" monitor from dx.com
Native resolution is 480x232

All the "car" electronics are pretty lax with the power requirements as they must run on a depleted battery or cope with the alternator pumping 15V at high revs. I succefuly powered the display from a 9 Volt battery and also from a very shady 12V power brick that varies between 13 & 11V under load. Anything between 9 & 16V will do.

For text-mode readability, add this to /etc/default/console-setup

Code: Select all

CODESET="guess"
FONTFACE="TerminusBold"
FONTSIZE="14x28"
And some tweaks in /boot/config.txt to fit everything in the visible area of the screen:

Code: Select all

disable_overscan=0
overscan_left=-12
overscan_right=4
overscan_top=-10
overscan_bottom=-26
# you might have to tweak those for your screen
sdtv_mode=0 # NTSC
sdtv_aspect=3 # 16:9
and you get a 47x16 usable text mode.

The screen's backlight will stay on even after the text console blanks the screen. The only way to completely turn off the car LCD is with

/opt/vc/bin/tvservice -o

then turn-it back on with

/opt/vc/bin/tvservice -n "NTSC 16:9"

AndyA
Posts: 31
Joined: Mon Sep 17, 2012 6:02 pm

Re: Car Rearview Screens

Mon Sep 17, 2012 8:54 pm

The display seems to run fine down to about 5.5V.

Internally there is a 5V regulator (and a 3.3V regulator that then runs off the 5V). If you remove the main voltage regulator and solder a wire on to it's output pins you can run the display from a 5V power source (e.g. USB).

I've posted instructions on how to do this for the display in the first link, I suspect the second link is the same display internally. Since it was my first post and had external links and a lot of images it's currently awaiting moderator approval but should hopefully be up soon.

Krebsy
Posts: 10
Joined: Thu Sep 20, 2012 2:55 pm

Re: Car Rearview Screens

Thu Sep 20, 2012 3:33 pm

I'm also going to crack my screen open and either rip out the regulator or use the (seemingly pointless now) 5v to 12v DC-DC converter I spent a week sourcing.. :)

K.

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