Hi guys, I want to make a GPS speedometer head up display for my car. Just like the Globaltop HG-100. Unfortunately I can't buy them anymore because the model is out of production.
I looked around to plan my purchases but now I'm just confused. I have the programming and electronics skills to join the parts together, but I have no idea what parts are best for my application.
You might want to look at building a version of the MPGuino, and mounting it above the dashboard, so it's kinda-sorta like a HUD, without the expense of making a projection display.
For the HUD I would experiment with what works... maybe try putting some different colored papers on the dash to see how it reflects on the windshield. Most cars I have seen with this feature seem to have a coating on the windshield in the area where the display should be reflecting.
As for the arduino, you probably want something small, so maybe a barebones one from moderndevice.com or similar ones available from Sparkfun and others.
The GPS probably doesn't have to be anything fancy, I have a low cost one available in my store, http://www.jkdevices.com/arduino-gps-001 and there are also several available from Sparkfun.
As far as the display, it depends on what you want to show. Like Chris said, a few 7 segment displays should work fine. If you are doing a true heads up display, you will need to test reflectivity in the window. Otherwise if you are just mounting a display to look at, then you just need something that you can make look good in your car.
After testing everything, probably just hardwire it all to a bare bones or other small Arduino.
Since this will be in a car, you will need a regulator that can dissipate enough heat for the 12 - 14 volts you will be regulating down to 5V or 3.3V. You also may need some extra filtering on the power to keep any extra noise out that may be caused by a car.
Another option for the display would be to use a VFD (vacuum fluorescent display) - they tend to be much brighter than most 7-segment LEDs, and you can generally find ones that are HD44780 compatible (which means they should be workable with the Arduino LCD libraries).
I am not sure, but you may be able to find a KS0108-compatible VFD; I am not sure they make graphical VFDs, but they might! Actually - found this:
Maybe putting some mirrors in to reflect the image but the mirrors must not be quite visable... Just an idea. Using a mirror is fun to reflect a laser beam (which I have done in the spirograph)
I'm also interested in building a GPS speedometer! jonnyroy, have you all the part to build one? I want to use it for sport with a 60 mm digit display.
Does anyone know if the speed displayed by a tomtom sat nav is calculated in two or three dimensions? Cos I was driving down hill and wondered whether it took the descent into consideration.