Heads up Display?

[2003protege]

Yeah, I think what is also contributing a big deal to the double image being a problem is the size of the numbers that display uses. I plan on using a bigger display, so hopefully the double image won't interfere as much.

I have most of the stuff ordered for the mpguino/heads-up-display. Can't wait to get started.

[FastPlastic]

Originally Posted by 2003protege

Yeah, I think what is also contributing a big deal to the double image being a problem is the size of the numbers that display uses. I plan on using a bigger display, so hopefully the double image won't interfere as much.

I have most of the stuff ordered for the mpguino/heads-up-display. Can't wait to get started.

Larger number will probably help a lot. Less overlap that way. I guess if it does end up bothering you you could pull the fighter plane trick. Have another panel just before the windshield that has a semi-reflective surface. Technically that way your not tinting the windshield. Don't know if that will get you around all the laws or not.

[vtec-e]

Originally Posted by FastPlastic

......the fighter plane trick. Have another panel just before the windshield that has a semi-reflective surface.

This is a total drool fest!!

[2003protege]

So, I had somewhat of a moment of realization...

Problem #1 - Cannibalizing a Clock for its LED Display
I got my clock which i had planned on using as a seven segment LED source. I took it apart, and as I suspected, it has a single integrated circuit running the whole display. To my surprise, any given input to the LEDs will light up two LEDs - not just a single segment of a number. I suppose since the tens-of-minutes digit only goes to 5 and the tens-of-hours digit only has to display 1 it's no big deal.

Problem #2 - Brightness
There is a plastic, tinted cover over the display, and a translucent, red film over the LEDs themselves, so when those are removed you have a very bright display...but i don't think it's bright enough still. I'll have a chance to find out this afternoon when i can take it out in sunlight. But I think the solution is going to have to be a custom seven-segment display in order to get the size of display I want (I would like bigger digits than the LCDs can offer).

Problem #3 - The double image. I just plain can't deal with this. It looked good at night, but it still bugged me...

Originally Posted by FastPlastic

you could pull the fighter plane trick

And I was hoping to stay away from this, but it's looking more and more like an inevitability. Hopefully, I can just have a cantilevered piece of plexiglass in order to maximize visibility.

Anyway, parts are going to be getting in soon for the MPGuino, so I'm pretty excited.

[dcb]

I managed to get the backing off the mirror, but the range of angles was so picky as to be impractical. So I tried a chunk from another project. It shows some promise as an inexpensive and simple HUD as well (might need brighter LED and/or smoke cover, non diffuse LEDs might make more sense too):

[2003protege]

I ordered about 60 narrow-angle, non-diffused leds from superbrightleds.com last week. Hopefully they are powerful enough for use in daytime.

[2003protege]

SUPER STOKED!!

So I received my non-diffused leds from superbrightleds.com. They're red 5000mcd 15deg 5mm LEDs. THey have a nominal voltage of 2.1V.

I hooked six up in series and wired them to the battery (car was off, so 12V give or take) I'm happy to say that the reflection off the window was too bright to look at (OUCH!), and that's at 2.0V, still got a decimal to work with!.

That was at night however. The real test will be in the daylight, and hopefully I can have a diffusing layer on top of them without losing visibility in the daylight.

[2003protege]

OK! I made this diagram. Hopefully it will be pretty self-explanitory.

I plan on having two separate layers. The top layer will have a seven-segment number pattern in it (made out of mdf, cut on a scroll saw). The bottom layer will have holes drilled for the LEDs in a pattern that puts two LEDs under each segment of a number. The seven-segment number layer will be a bit thicker than the hole pattern layer and the whole assembly will be painted flat black in order to minimize glare. As mentioned I want to have a diffusing layer positioned in-between the hole-pattern and seven-segment layers. It might be as simple as a sheet of copy paper, but we'll see how bright these are in the daylight.

P.S. I forgot to mention that I also received my white on blue LCD screen and my binary-to-seven-segment ICs (74LS47's) in the mail today. THis project is gonna rock!

[2003protege]

Good news:
The LED reflection is too bright to look at in full daylight, and covered by a sheet of paper, the light is definitely visible

Bad news:
My original plan to have a cutout of the seven-segment digits is not going to work. I drew up a custom seven-segment design in AutoCAD, printed it out, and was cutting it out on a scroll saw. I was getting pretty good results on the top, but on the other side, the lines were pretty wavy.

So now i'm considering what to do. Maybe I could take the patter to a professional print shop and get a transparency made? I'm also considering scaling the numbers up just a bit and using straight edges of aluminum foil to screen off a pattern.

Any ideas out there?

[Nevyn]

Use a flexible cutting board from the kitchen dept. They're like 1 or 2 mm plastic. Use tape or something to mark off the segments, then spray it black. It'll diffuse nicely, and be opaque everywhere else - as well as cutting brightness down a little.