So I want to start a car- Explain to me like i'm five


  • Community Helper

    Yup, that board is the right one. You'll have to let us know how you go with positioning the reader for unlock.
    You could also conceivably use more than one reader on the same arduino and have the second for starting the car.



  • Yeah I'm trying to figure out where it would work. I feel I could put it directly under the handle but that is mostly metal.. Along with my car. What else would I need besides the board I showed and Arduino to get this project going?


  • Community Helper

    just a power supply appropriate for the arduino and the reader unit, probably 5v, regulated. Plus relays and such to translate what the arduino does into solid electrical connections for the vehicle side.
    If you have electric locking you'll need a relay for that also.
    Rather than the door handle you could place the unlock reader in the empty part of the mirror housing or behind the corner of the window at the dashboard end. Another person I know with an implant from Amal set his car up with a reader behind some plastic flashing that was on the vehicle, outside the metal but well hidden and protected.



  • I really like the Mirror idea. My side mirrors are indeed plastic!


  • Community Helper

    Just make sure you plastic wrap the reader, so it's waterproof!



  • Will do! Are there any websites or links that you would reccomend me going to to read up on programming arduino and NFC along with the resistors? This was I have a decent understanding of what I'm doing.


  • Community Helper

    Relays mate, relays. What you're actually doing is using the arduino to activate a relay which basically closes a switch which isn't electrically part of the arduino circuit. That way the cars 12 volts isn't going through fragile electronic components in your control circuitry.
    MrStein's pictures and diagrams up top explain the physical aspect of the idea quite well, and there should be a thread of mine here where I put a quick and dirty car start sketch that will work with the PN532 reader unit you're getting. It can be adapted so that the outputs trigger anything external basically, as long as you're using the relays to keep everything seperated nicely.
    For further reading on Arduino, the best source is the source: http://arduino.cc/
    They've got plenty of tutorials there, and a forum where you can ask questions of those who've been coding for longer and have some experience.
    There are also a heap of projects out there on the web, google will get you there right quick.



  • Thank you very much for your amazing replies. I mean't to to say relays lol not resistors. I was still waking up before work when I typed that. I realized today that my car does actually have plastic door handles so my original idea might actually work. I'm thinking up having the sensor positioned up from underneath the handle so when I go to grab for it, it will unlock the door.


  • Community Helper

    Yes! That's exactly what I plan to do, though I'm going a step further and removing the door handles. Later. When I don't need to drive for a whole weekend! (Hot rod style door popper kit!)
    I just noticed the code I put up has become a little bit butchered in the forum change, I'll have to see if I can fix that up.
    Also, no problemo!



  • That would be pretty cool! I'm honestly just afraid of doing that just in case it happens to malfunction. That way I can just revert back to my key if all else fails.


  • Community Helper

    I've got andersen type plugs on my car for emergency power injection without popping the bonnet, juuuust in case!
    It's usually required by law to have a secondary method of entry in case of emergency, so I'll have hidden mechanical release as well.



  • That'll honestly be really cool to see. Aren't your doors all metal though? Won't the signals not be able to pass through?


  • Community Helper

    I have an R31 Skyline that I run around in at the moment, and that has plastic handles. What I'm investigating is whether I can remove the handles and put a blank piece of plastic there, either paint over it or have it in the standard black.
    The secondary method is going to have to involve a cable operated release, which is a bit of a pain but still. It's doable.
    I want it so that I can walk up to the car with my hand out and have the popper put the door in my hand.



  • Oh my god!! You have a skyline!! That's amazing!! I'm over here with a s13 240sx.


  • Community Helper

    Oh nice, I always liked those and their bigger siblings. Nissan make good cars, and luckily used plenty of plastic in the newer ones.
    My '68 Dodge Dart (Australian '70 valiant hardtop) on the other hand, that's going to be a real experience to upgrade the locking and starting on. The only advantage is that there's no steering lock in that one.
    That's why I've opted for messing with the R31 first, it'll be a few less headaches I think.
    I'm still waiting on some relays before I can start though.



  • I'm still doing all of my research into everything. I need to hurry up and just buy the arduino, board, and ring and just start messing with everything. That'll honestly be the best way for me to figure it out.


  • Community Helper

    Definitely. For the prototyping stage you might be best to get an Uno or Mega, figure out what you'll need at bare minimum and then perhaps back it off to a nano or pro mini.
    The mega would be good fun to play with though, and you'd be able to reuse it for later prototyping once you've got a dedicated unit put together for a car.
    That's what I tend to do anyhow, start off on a mega and then once I've decided properly what I'm doing, scale it back for the permanent unit.



  • I'm sorry I'm honestly confused on what you mean by the Uno or Mega. Sorry still a Noob.


  • Community Helper

    Lol, my bad.
    Arduino Uno is the basic full sized board, you can pick them up on eBay easily enough. They run an atmega328p and have a 'standard' amount of IO pins.
    The Arduino Mega 2560 runs a more capable atmega chip, with more memory for program space and more IO pins.
    They will both run the same Arduino code, with some allowances for pin out differences.
    I like to start with a Mega with the capability of putting everything if can think of onto it, then condense things down until it's a little more efficient. That way you can then see if you're able to shift your prototype down to a less costly Uno unit or maybe even a Pro Mini or Nano. Both of those are cheap, and small enough to incorporate into a prototype breadboard or basic circuit.



  • Ah Okay thank you for explaining that! Makes total sense now. This will definitely help me out. I think I'll do the same as you and just start out with the Mega.