View Full Version : Prop with LCD rear view mirrors

01-24-2009, 01:02 AM
Wondering if anyone has had an experience using the prop with the standard TV drivers on rear mirror LCDs, like this:

The resolutions are defined as 480 x RGB x 234 pixels and 240 x 800RGB
If anyone has pictures of prop driving some smaller LCDs (<6 inches), I'd appreciate seeing how it looks and hearing about your experiences.

Phil Pilgrim (PhiPi)
01-24-2009, 01:27 AM
It accepts both PAL and NTSC, so the standard TV drivers should work.


01-24-2009, 01:51 AM
I've used a 2.5" PAL/NTSC display. It's a bit small but quite legible.


Amateur radio callsign: G1HSM
Suzuki SV1000S motorcycle

01-27-2009, 12:17 AM
The Hydra manual specifically states the drivers will not work with LCDs due to the long horizontal sync time. I'd really like to know if anyone has had success with these. Pictures of how the text and images look on LCDs this small would be helpful if anyone has completed projects with them.

Paul Baker
01-27-2009, 08:31 AM
I see a bunch of people getting tickets from thier local law enforcement officers with this device. As I mentioned in the other thread, its illegal to display movies or TV in sight of the driver while the car is in operation. I think this type of display would be particularly susceptable because it's in clear view of any LEO that are around you and it partially obstructs a part of your vehicle's safety system (being able to see behind you).

I don't know if text display would be subject to the same laws, you might be able to get away with it (Probably depends on the loocal law). Not all jurisdictions have these laws, but many do, most·were enacted after a spate of accidents caused by the drivers focusing on the movie/tv show instead of the road in front of them.

I just looked up your state's laws and they do have it, from: http://www.ncga.state.nc.us/gascripts/Statutes/StatutesTOC.pl?Chapter=0020
§ 20‑136.1.· Location of television viewers.
No person shall drive any motor vehicle equipped with any· television viewer, screen, or other means of visually receiving a television broadcast which is located in the motor vehicle at any point forward of the back of the driver's seat, or which is visible to the driver while operating the motor vehicle. (1949, c. 583, s. 4.)
So it appears·a data·display would be exempt.·An interesting note, notice this was enacted in 1949, so there evidently was some enterprising individuals who somehow mounted one of those huge·vacuum tube based TV's in the front of their vehicle (or maybe they just set it in the back seat facing forward so the driver could watch it through the rear view mirror), that would have been a sight to see.

Paul Baker (mailto:pbaker@parallax.com)

Post Edited (Paul Baker) : 1/27/2009 1:56:44 AM GMT

Cole Logan
01-27-2009, 09:15 AM
Heres a Custom 1959 El Camino with a Tube TV mounted in the dash.


Post Edited (Cole Logan) : 1/27/2009 2:27:28 AM GMT

Paul Baker
01-27-2009, 09:22 AM
Cole Logan said...
Heres a Custom 1959 El Camino with a Tube TV mounted in the dash.

http://i65.photobucket.com/albums/h230/n1elkyfan/Propeller/UltimusRtIntCU-vi.jpg (http://i65.photobucket.com/albums/h230/n1elkyfan/Propeller/UltimusRtIntCU-vi.jpg)

And check out the stylin car phone http://forums.parallax.com/images/smilies/smile.gif

Paul Baker (mailto:pbaker@parallax.com)

01-27-2009, 09:22 AM
Awesomeduck said...
The Hydra manual specifically states the drivers will not work with LCDs due to the long horizontal sync time.

I use the standard TV drivers with the composite input on a portable DVD player's 7" LCD display. Works just fine.

Rgds, David

01-27-2009, 09:54 AM
Paul, based on your location and number of posts I gather you work in the legal department at Parallax. I appreciate your concern, but I have no intention of watching movies on my rear view mirror. In fact the idea of watching a movie on a 3" display never even occurred to me, but I guess there are some youngsters out there that might get crazy ideas.

I intended to hook up a Prop board to the LCD display and then interface to OBDII, tri-axis accelerometer, GPS module, backup camera, ultrasonic sensors and maybe a few other odds and ends like temp sensors.

I bought the Parallax 3.5" color LCD this weekend, hopefully it will be a good starting point. I really wish Parallax made a small 4" or so VGA LCD. That would be awesome. Maybe with a built in speaker, and built in IR receiver that you could actually tap into and use in the project unlike the one on the 3.5" LCD.

Several people have mentioned the "standard drivers" and I now realized I am looking at the Hydra HEL graphic engine. I was thinking of using the tile and sprite engine to generate text and based on the acceleration and other sensors some sprites that might appear when the car has excessive tilt or acceleration. I guess I'll try out the 3.5" when it gets here and if the results are good post some high res pics.

Paul Baker
01-27-2009, 12:10 PM
Nope there's no official legal department @ Parallax. I do have experience with the legal system (IP rights) and Parallax, but the two were seperate things. I figured based on your post that this wasn't your intent, it was more an observation that such a product would likely lead to such activity (unless the intent is to use it for a back up cam, I can't think of an average person's use for such a thing).

Paul Baker (mailto:pbaker@parallax.com)

Carl Hayes
01-27-2009, 02:02 PM
Paul Baker said...
unless the intent is to use it for a back up cam, I can't think of an average person's use for such a thing.
Average person?· What's that?·

Uses I contemplate would be:

(1)· Backup mirror (substitute for rear view) on a motor home (requires mirror-image display!)

(2)· GPS map display

(3)· Trip schedule display including multiple trip odometers

(4)· In my case, used in a transmitter-tracking system, a display to show the calculated locatiion of a rogue transmitter that is being tracked.· I'm developing this system now.· It will include an RDF to get the relative bearing of the transmitter, a compass to give vehicle heading (so the true bearing can be calculated), a GPS to give vehicle location, and a transmitter fingerprinter to tell each transmitter from each other transmitter.· One or two Propellers to calculate all this stuff, triangulate the transmitter, and nail him..

(5)· Engine/vehicle operating parameters display

(6)· Inside/outside temperature and vehicle speed, heading, track history

(7)· See?· There ain't no "average persons" in these fora.

· -- Carl, nn5i@arrl.net (mailto:nn5i@arrl.net)

01-27-2009, 02:41 PM
Carl Hayes said...
In my case, used in a transmitter-tracking system,...

I got egged by a couple of bozos the other day while riding my bike home. I certainly wish I had a transmitter with magnet that I could throw at their car and locate them when I went to the police. Not that the police would probably do anything, but it would satisfy my geek side...

Anyway, backup cameras can also be used for parking and avoiding running over small children. Plus, who wouldn't want a customizable display in their car?

Paul Baker
01-27-2009, 02:43 PM
What I meant is the average person doesn't have the technological know how to implement nearly everything on that list (except plugging in a back up cam, which is why I listed it).·I don't think the company was thinking of people capable of designing thier own information systems when they made it but rather the crowd that is into after market modifying thier ride, that market is much much larger than ours. Thier·intended market is clearly shown in thier marketing photos, one has a soccer game shown (football for the rest of the world) and the other has a racing game displayed on it. Heck they even state in thier features "Two channel Video Input (video 2 for back car view)", channel 1 is intended for the car's A/V system output, ie the programming·to the rear passengers. Of course it could be used for other things, but that was the manufacturer's original intention. Everyone on these forums (fora) is most definitely not·an average person, I never made any claim that they were.

Paul Baker (mailto:pbaker@parallax.com)

Post Edited (Paul Baker) : 1/27/2009 8:21:24 AM GMT