Im working with a computer for my car.
It have a 3,2" TFT screen wich shows speed, gps coordinates, wvo control, and info about when next service is etc.
I want to have the ability to store the km-info about service in a way that I can change the info without uploading new scetch.
Im thinking maybe SC-card, but that require a SD-card reader for my arduino. Maybe I can use EEprom an easy way?
And I want to control settings with ONE button only.
When setting wvo, I use only one button in a way that U can click it, or hold it for 2sec to use two different functions.

Anyone can help me how to do this most easily?

Using a Arduino Mega

Thanks..
But I figured it out;)

still working on this.. feel kinda noob, and well I guess I still am:P

anyway, have tried to calculate this in arduino but dont know what variables to use etc..

Is this simple to make for anyone wanting to help me?

Hi.
Have read about uploading to arduino projects with rx, tx pin?
How do I do that?
I want to do this with my arduino chips on breadboard..

thank you;)

how do I do that i arduino?

I got the gps unit working with an arduino mega;)
But it gives me coordinates like this: 5936.681N, 547.789E

Easy way to get 59.611344,5.796477 ?

I also have problems with this.
Everythings seems to work fine, Cardinfo is showing....

But Im not able to write to a file..
Would apreciate if anyone knew whats causing this problem....

Need some help here. I have never worked with photocouplers before, so this is totally new for me.

Ive connected a nec 2501 to control an input to arduino from my car. it should read a car switch (12-15v) on/off.

Connected like this:
Car 12 -> anode
cathode -> 1k resistor -> GND

Arduino 3.3v -> Collector
Emitter -> arduino pin 2
Emitter -> 10k resistor ->GND


The voltage from the car varies from 12V to approx. 14,7V
When its 12V i measure about 1.something volt on the emitter
When car voltage to anode is 14.7Volt, I got 3.4volt on my emitter.

WHY?
Whats the point of a photocoupler if the voltage varies like this?

Or is it badly connected?

thank you;)
that one is perfect!

Im working on a simple computer for my mitsubishi pajero gen1
I want to have speed monitoring on a lcd screen.
I know there is a pulsesignal from the speedo, but dont know if its possible to use this with my arduino, or how to do it.

So I was thinking to put a GPS module to it to get speed. Then I also can get lat/long and altitude.

Any tips of a cheep and easy to use gps module?
Best if it has external antenna, as my dashboard is metal and arduino is placed under it.
thanks!

Got it working

Also, the reason I couldnt store 9 was that I had it like 09

I get an error everytime I try to save 09 in my EEPROM.. dont know why.. maybe the chip is corrupt..

anyway, if I cut it in pieces, like two numbers in each eeprom address like this:

EEPROM.write(0, 1);
EEPROM.write(1, 00);
EEPROM.write(2, 00);

how do I put them together again when reading so I get "10000"?

or maybe I can store them in progmem... hmmm

cut them up then?
cause I cant store them there as they are now..
and also, I cant store a value like 09 in EEPROM