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problems calibrating rpm — Parallax Forums

problems calibrating rpm

sport270sport270 Posts: 82
edited 2014-01-02 16:39 in BASIC Stamp
Using bs2 and 2x16 backlit lcd screen for 3 line rpm monitor.
Two of the shafts use 6 tooth gears so reading in hz is working fine. The 60 tooth ones I count for 500ms then multiply by 2. I tried to count for 312ms on the 37tooth to calibrate rpm but would not work.. Tried using freqin and multiplying by 1.62 and that doesn't work either. Any ideas?

Comments

  • sport270sport270 Posts: 82
    edited 2014-01-02 10:52
    That was 60 tooth gears
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2014-01-02 10:57
    sport270@yahoo.com wrote: »
    Tried using freqin and multiplying by 1.62 and that doesn't work either. Any ideas?

    Stamps can only do integer math (no decimals allowed.)
    You can * 162 and truncate the 1's and 10's places.
  • CatspawCatspaw Posts: 49
    edited 2014-01-02 16:39
    uh, just a quick look at the thread. I have no idea what I'm doing. Been out of it suddenly for a year or two. Getting back in. When you want to check some ones pulse, you count the pulses in 6 seconds, then multiply by 10 ( so you get beats per minute [60 seconds.]
    Could this math be applied to the 37 tooth gear? I don't know what your sampling rate is or what range of rpms the shaft would be rotating at. But could you use 60 mS, or 600 mS. etc.

    Also, what are you counting (reading)? The gear teeth or some mark on the gear?
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