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please i need some help, i have a project but not sure how to ,,,

hannah_girl

hi all, my name is Hannah, i have built a car into a mini caravan, the car used to be a 2004 Citroen C5 estate, it has hydro suspension, which is electronic, i have manage to bypass the ecu which controls the hydro pump and fitted a remote switch, which you can raise or lower the car, that side of the project is fully working, but this is where i need some help,

 

the car has a height sensor which sense if the car is too high or too low etc, i wondered if i can use my Raspberry pi B to raise or lower the suspension when the car moves about,

i have tested the sensor which runs of a 5v power supply when the car is lower the output signal is 0.3v, and when its on high its about 4.3v. for normal height its about 2.3v

i am great at wiring, but a tad rusty to when it comes to software and programming, if anyone could point me in the right direction, i would be totally grateful,

if you would like more info on the c5 caravan project, please check out this video on you-tube,  https://youtu.be/crk6tFNhkYQ

thank you for your time, Hannah

Parents

  • Hello Hannah,

     

    Any particular reason why you are planning to use a Raspberry Pi?, usually a RPi is overkill for simple tasks and this sounds like one. From the little information we got maybe you can accomplish what you need with a cheap Arduino or even simpler micro-controllers like the ATtinys.

     

    Another important thing to know is what kind of output is needed from the sensor (is it analog or PWM -it sounds analog to me) considering that a RPi doesn't have analog outputs (you will need a DAC) or if the output is PWM, the RPi handles the PWM by software (which may be an issue as software in RPi is asynchronous) as far as I know.

     

    Finally if you will definitely need a RPi for this, a simple Python script will probably be handy for your needs.

     

    Luis

  • in reply to luislabmo

    the reason why i was thinking of a Raspberry pi is that i got 2 sitting in my draw doing nothing so didnt know if i could use them in my project,

Reply Children
  • in reply to hannah_girl

    Gotcha!.

     

    Like Enrico said, you can use a RPi but you will need something in the middle as the RPi is not capable of analog (you will need to add a DAC or an Arduino that does the analog part for you). When coding in the RPi, the easiest I can think of is with Python which is already installed in Raspbian if you decide to go with this SO.

     

    Luis

  • in reply to luislabmo

    ok that makes sense, so which arduino would you recommend? i just had a look in my draw and i found a 2 relay module which i can use between the rpi and the hydro pump, thank again hunnie ,

  • in reply to hannah_girl

    It doesn't matter I guess, any of the basic ones will do what you need. I regularly use the pro-mini because that is the cheapest and the smallest one.

  • in reply to luislabmo

    Between a DAC and an Arduino, I suggest an Arduino, Amazon sells 5 Arduino Nano by 11 Euro. And these are not the cheapest, works fine and a more flexible, as well as better to program and connect to the Pi. I think that as you still have a Pi at home, it is not a bad idea because after setting the essential parts (sensor reading and car control) you have a powerful machine to do many other things. Just one I think now, is logging the number of times the pump is activated to place a max number of hours after starting the part maintenance, up to adding totally different features like mp3 player and more on your car because you have a Raspberry Pi.

     

    Enrico

  • in reply to hannah_girl

    I can't imagine that if you have been this creative so far, you won't keep coming up with creative ideas.  So, I'd go with the raspberry pi so you can have one code base/brain box for all your features.  For example, you could have it talk to you when its loaded and ask you for voice confirmation.  They sky would be the limit to adding on features and sensors.  Just my two cents.

     

    To start the project as you describe, it will be good to have a breadboard and some jumpers so you can wire it up on your kitchen table and work your code.

     

    See ya',

    Sean