Automobile Keyless Entry

[lalalandrus 16]

In this day and age, we should not need to use any keys or buttons. I have done away with the key remote in my car using this simple setup. I came to the same conclusion as this gentlemen in using the apple nike+ sensor to provide a proximity sensor to the car. 

 

https://www.sparkfun.com/tutorials/135

 

His code lacks a couple things that I was looking for.

1) decoding of the apple serial protocol so that i can use any NRF module

2) detection of when to stop strobing the remote (when the key is inserted)

3) ability to open the trunk

 

and since I can detect when the key is inserted, I can do other things when the car is on like strobing the garage door opener, 

 

To accomplish 1, I found that some genius went about decoding the modules to be decoded with NRF modules

 

http://dmitry.gr/index.php?r=05.Projects&proj=05.%20Nike%20plus%20iPod

 

Also helping this along was energia and the already written NRF24 library. 

 

notes about my design and things I learned:

 

- my design is based all on a repeating 10ms timer which is a good base for modifying this code to work for different scenarios

- i am a fpga designer and some of the code is not as efficient as a c++ programmer would make it 

- one could optimize the interrupt routine to use less time by using a global counter and variables to store offsets rather than individual counters

- my mazda remote is active low so the signals had to be inverted

- i tapped into my car through the mazda  keyless module. 12v and gnd is provided. an additional signal which pullses low at a 1khz rate when there is no key inserted, it is high when a key is inserted, this powers "car timeout"

- i originally had everything on one board, but it seemed there was too much interference for the NRF to pick up the sensor properly 

- since there were a lot of rf devices decoupling capacitors was very necessary. 

- there is a 24 second timeout before my car relocks if there is no door opened, i kludged a single button press keep alive  every 20 seconds using delays :-( i dont like using delays they seems so unclean.... an upgrade would be to use the -64dbm to detect that you are actually in the car and stop the strobing, ymmv and i have not implemented this (RPD register 0x09 bit 0) UPDATE: IMPLEMENTED IN NEWEST CODE

- whenever the key is in the car, the car will cycle every ~2.5 seconds through the two parkade doors. the remote will auto shutdown if it detects a constant press so i have added a remote_pause to prevent this

- the trunk has another msp430 performing capsense on the key hole and will activate another nike+ sensor to open the trunk. i am in the process of upgrading the sensitivity of this using swept frequency capacitive touch which i will share once i get the kinks out 

- a cheap chinese buck module was used to reducethe voltage from 12v to 3.3v

- replace the *_sn vectors with whatever your nike+ sensor serial number is 

- avoid RF like the plague, even with one side guaranteed to be working, along with some issues with SPI, it was a PITA to get working the first time

nikerf.ino

printf.h

[bluehash 1,581]

@@lalalandrus Good stuff. Does your car come with keyless entry?

Also, .ino files are now allowed.

 

Ok. I made a mistake. In the process of editing your post, I deleted the two source files. Could you please re-upload it. I'm unable to upload files from where I am right now. Keep them at .ino

I have a backup - just in case.

[lalalandrus 16]

yes it came with keyless entry, it just was cumbersome especially when the remote is the size of texas AND i fried my remote one day

 

perhaps i should call this "proximity entry"