Instructables
Picture of Car Digital Compass & Thermometer
20130410_174041.jpg
I'm not really good at finding places and direction but at least I'm able to read maps and compass. These days, GPS navigation systems are getting more popular, so probably some people would say why I need a  compass. Well, first off, I like gadgets and if I can make one, that will be much better to enjoy it.  So, I decided to make a digital compass for my car. 

I started with very basic function, showing bearing and heading angle from a digital magnetometer on an LCD, but there are a number of digital and analog pins are left unused on the microcontroller (Arduino compatible, JeonLab mini) so I added a digital temperature sensor and a phototransistor to adjust the brightness of the backlight (single LED) of the LCD.

I still have more than a few pins available and have a plan to add more sensors such as an exterior thermometer, anti-theft device, etc. (any suggestion would be appreciated!)

The picture shown in this Intro page is the fully assembled and mounted on top of the interior mirror of my car showing the bearing, angle and current interior temperature. Unfortunately I didn't take a lot of pictures when I assembled the electronic parts, but I'm sure someone who are interested in making one of these will be able to follow easily the schematic diagram I will show in a couple of steps later.
 
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efoo2 months ago
any problems with magnetic interference from your car?
JeonLab (author)  efoo2 months ago

That's why I put the sensor on the wind shield close to the interior mirror where the magnetic field interference is minimal. It works fine.

efoo JeonLab2 months ago

cool, thanks

dmwatkins6 months ago
Well done! I may add some of your features to my arduino MPG display. I would suggest adding MPG info to your display... by following the "MPGuino" schematics available online, it only requires a few resistors and diodes, 2 additional Arduino pins, and tapping into a fuel injector lead and the wheel speed sensor. From those 2 inputs, as well as looking up the specs for both those sensors for your vehicle, you can then display mpg, engine rpm, vehicle speed, and a custom odometer.
JeonLab (author)  dmwatkins6 months ago

Oh, that's interesting stuff to add. Thanks for the information. I wish I had more time to make things. :-)

BowMan8316 months ago

This is pretty impressive. Have you played around with any raspi stuff? Seems like you could have even more fun.

JeonLab (author)  BowMan8316 months ago
Thanks!
I'm thinking to get one of those soon.
UOS1 year ago
Very useful! Thanks!
JeonLab (author)  UOS1 year ago
I'm glad someone found this useful.
Thank you.
kebmoore1 year ago
Nicely done. I have been planning to build my own digital compass since my new truck didn't have one installed. I want to start with the compass and an OLED display, then add temperature/humidity and maybe even GPS logging.
JeonLab (author)  kebmoore1 year ago
Thank you. I also think about adding a GPS module. Good luck!
mcsxr21 year ago
How about Tilt and Inclinometer for the 4x4 guys
JeonLab (author)  mcsxr21 year ago
That's good idea. I'll think about it. Thanks!