Chief Delphi - encoder counting and onscreen feedback *ASAP

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encoder counting and onscreen feedback *ASAP

Hey,
I am working on a project and need some help. I am using a vex wheel encoder connected to a shaft which I need to see # of revolutions and RPM on my computer. I was thinking I could do this through the real time link with the controller. I really have no idea where to start and I have a signifigant time crunch on this. Also what is the max RPM that the encoder can detect, I am planning on using it at about 450 RPM.

Thanks..

P.s. this is for 5:00 tonight (2/27) any help would be appreciated.

Re: encoder counting and onscreen feedback *ASAP

The vex encoder ticks 90 times per revolution. That is ~700 ticks a sec. at 450 rpm. The vex controller may be able to handle that, but I haven't tried it.

You could use the terminal built into IFI/Intelitek Loader. I assume you will want to use EasyC if you're on a tight schedule. If you are not familiar with MPLab, interrupts, and timers, then you want to use EasyC.

I would suggest somthing like this(this is easyC).

Code:

void Main (void)

{

  unsigned long count = 0;

  unsigned long old_count = 0;

  unsigned long timer;

  unsigned long old_timer;

  int rpm;

  int diff;



  StartEncoder(1);

  StartTimer(1);

  while(1)

  {

     timer = GetTimer(1);

     if (timer - old timer >= 1000) //only do the calculation once a second.

     {

        old_timer = timer;

        count = GetEncoder(1);

        diff = count - old_count;

        old_count = count;

        rpm = (diff * 60) / 90; //# of ticks * 90 secs / 90 ticks per rev.

        PrintToScreen("RPM = %d\n", (int)rpm;

     }

  }

}

I have not tested this code, but it should at least get you started.

I have attached an EasyC pro project(vex) with this code.

Re: encoder counting and onscreen feedback *ASAP

Greg, did the encoder win or did you?