Page 6 of 55 FirstFirst 12345678910111213141516 ... LastLast
Results 51 to 60 of 541

Thread: Anyone interested in serial controlled Relay/Input card?

  1. #51
    Raw Wave
    Join Date
    Jun 2003
    Posts
    1,823
    Quote Originally Posted by DjBac
    Is it possible when you go over 20km/h to auto-lock the doors?? But it should then know that doors are locked so that when you stop ie. at a stoplight it shouldn't lock again!! Is this possible?
    Yes thats possible. I have actually though about this. This need to be done on the windows software, of course the card need to know your speed. The easisest is to sense the handbrake on...once on the door will unlock and once off the door will lock.

    But then than can be done without a controller or PC

    Hmm practical or not thats up to you.

  2. #52
    Maximum Bitrate Danceheaven's Avatar
    Join Date
    May 2002
    Location
    Essex, UK'er
    Posts
    664
    Quote Originally Posted by DjBac
    Is it possible when you go over 20km/h to auto-lock the doors?? But it should then know that doors are locked so that when you stop ie. at a stoplight it shouldn't lock again!! Is this possible?
    Like ricky said proberly best to leave this to the software side of things
    as for functionality or features this can all be discussed later once the hardware is built, im hopeing this card is so flexible that it will acomandate any functionality or feature needed
    Co Develper of A.I.M.E.E Automotive Intelligent Multimedia Entertainment Engine
    www.aimee.cc

  3. #53
    Raw Wave
    Join Date
    Jun 2003
    Posts
    1,823
    im hopeing this card is so flexible that it will acomandate any functionality or feature needed

    This is exactly what Im trying to achieve. I hope most of the functionality needed had been covered for most applications.

    Maybe theres more features need including for flexibilty? I have seen some card with DAC...but whats the use of that in cars?

    8 Relays, 8 digital inputs and 4 analog is it really enough? I do really hope so because I dont wanna go overkill as Im keeping the cost down to minimum.

  4. #54
    Maximum Bitrate Danceheaven's Avatar
    Join Date
    May 2002
    Location
    Essex, UK'er
    Posts
    664
    Quote Originally Posted by Ricky327
    im hopeing this card is so flexible that it will acomandate any functionality or feature needed

    This is exactly what Im trying to achieve. I hope most of the functionality needed had been covered for most applications.

    Maybe theres more features need including for flexibilty? I have seen some card with DAC...but whats the use of that in cars?

    8 Relays, 8 digital inputs and 4 analog is it really enough? I do really hope so because I dont wanna go overkill as Im keeping the cost down to minimum.
    DAC can be useful for some applications, such as a lot of my obdII info is in the form of 0-255 values but then a OBDII adapetr could be used for that purpose
    Co Develper of A.I.M.E.E Automotive Intelligent Multimedia Entertainment Engine
    www.aimee.cc

  5. #55
    Raw Wave rando's Avatar
    Join Date
    Mar 2004
    Location
    Redondo Beach, CA
    Posts
    1,973
    Nice project plan!

    I'm wondering if one or more the digital inputs could be set up as a pulse counter? So instead of returning its value at each output interval you would instead return the number of pulses (rising edges) received since the last interval. As long as the interval timing is tightly controlled this would allow us to do things like sample our on-board speed sensors, rpm sensors or anything else that produces rapid pulses. In some cases, the 100Hz polling interval might be good enough. Pulse counting just extends the maximum frequency to whatever the PIC/firmware can support.

    As an extension to the idea above, if you can invert the output to report period instead of frequency(i.e counts) then you'd really have something. Car speed sensors really measure distance. If you can provide an accurate time between pulses of speed sensor, you'll be able to produce very accurate measurements of average speed over the pulse interval.

    I know OBDII already does this and much more but it's kind of overkill for some applications. For those of us that would like to implement dead-reckoning in our navigations systems, the solution above would be near ideal.

  6. #56
    Maximum Bitrate DjBac's Avatar
    Join Date
    Jun 2004
    Location
    GREECE/Athens
    Posts
    702
    Quote Originally Posted by Ricky327
    Yes thats possible. I have actually though about this. This need to be done on the windows software, of course the card need to know your speed. The easisest is to sense the handbrake on...once on the door will unlock and once off the door will lock.

    But then than can be done without a controller or PC

    Hmm practical or not thats up to you.
    I think with the handbrake is more practical, right??
    how can this be achieved? maybe with some relays?
    Do you have something in mind?

  7. #57
    Raw Wave
    Join Date
    Jun 2003
    Posts
    1,823
    I think with the handbrake is more practical, right??
    how can this be achieved? maybe with some relays?
    Do you have something in mind?



    Under the handbrake there should be a switch somewhere, use this to activate a relay/s which can then control the central lock. You may also want to include the state of the IGNITION.

    So...the central lock will open when the IGNITION is off and the handbrake is on. Then lock when IGNITION is on and handbrake is off. The clifford alarm does this but it doensnt take the state of the handbrake.

    I havent done it, just some thought in my head but I cant see it not working.


    A cool factor?

  8. #58
    Raw Wave
    Join Date
    Jun 2003
    Posts
    1,823
    In some cases, the 100Hz polling interval might be good enough. Pulse counting just extends the maximum frequency to whatever the PIC/firmware can support.

    Im able to run the PIC at 115200 baudrate, with the amount of characters in the status string I stated earlier it is possible to update at about 311Hz. If we stick at 200Hz thats equivalent to 12,000 RPM, assuming 1 tick per rev. So it is possible to calculate the engine speed with no problem. I guess the application is almost endless, just a matter of being creative

  9. #59
    Raw Wave rando's Avatar
    Join Date
    Mar 2004
    Location
    Redondo Beach, CA
    Posts
    1,973
    Quote Originally Posted by Ricky327
    we stick at 200Hz thats equivalent to 12,000 RPM, assuming 1 tick per rev. So it is possible to calculate the engine speed with no problem. I guess the application is almost endless, just a matter of being creative
    I don't think that analysis is correct. At 12000RPM you'd get a constant stream of 1s or 0s (depending on phase) from that digital input line. That would be fairly useless. You'll need at least twice the sample rate as the highest frequency. Assuming your example (1 tick per rev), you can marginally reconstruct the input signal upto 6000RPM. But to get a feeling of the real problem, imagine what your stream sends at 5900 RPM? If you looked at only 3 consecutive status messages, you'd get the values 1..0..1 in both cases. To accurate determine what the RPM is, you'll need to look at MANY consecutive status messages (effectively counting sampled pulses). Hence the reason I was interested in the firmware pulse counter and/or period sampler.

    In any case, its just an idea. I understand that you're wanting to keep complexity down.

  10. #60
    Raw Wave
    Join Date
    Jun 2003
    Posts
    1,823
    Opps sorry my mistake, thanks for pointing that one out, I wasnt thinking straight



    However it can still be done because the PIC (some) have a built in CCP module. This can be setup to time a pulse interval and return the measured value in 10bit resolutions.

    From what you said we can still increase the sample rate alot higher than 200Hz but this involve changing the STATUS format from ASCII to binary.

Similar Threads

  1. Ewww sound card + video card on dual pci mini-itx reiser card = audio interference
    By psyclobe in forum Software & Software Development
    Replies: 7
    Last Post: 01-23-2008, 01:59 AM
  2. anybody tv/fm card troubles
    By marsjell in forum Software & Software Development
    Replies: 1
    Last Post: 09-01-2005, 07:08 AM
  3. Via Mini-ITX Epia 5000 serial port not working
    By vash in forum General Hardware Discussion
    Replies: 2
    Last Post: 08-13-2002, 08:48 PM
  4. help - video card problems
    By Cliff in forum General Hardware Discussion
    Replies: 4
    Last Post: 04-15-2002, 05:25 PM
  5. 2 db-9 serial ports PCI and credit card remote
    By moahdib in forum Classified Archive
    Replies: 0
    Last Post: 07-24-2001, 11:41 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •