I used a PIC16F819 microcontroller and a sensor from an old computer mouse (the remaining parts of one of my other projects Crazy Mouse) to make this simple measuring tape.
Do you want to make yourself? If yes read the rest of this instructable.
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Signing UpStep 1What you need
- Printed circuits (find files in the next step)
- Copper board
- Sandpaper
- Iron
- Circuit board acid
- 1mm drill
- Soldering tools
- 1x PIC16F819 microcontroller + socket
- An old mouse (or one of its IR shaft encoders)
- 3x BC547 transistors
- 3x common anode 7 segments
- 1x 100uF electrolyte capacitor
- 1x 470ohm resistor (1/8 watt)
- 7x 10k resistors (1/8 watt)
- 2x Simple push buttons
- 1x Simple switch
- 2x AA batteries with a battery holder
- 1x Wheel (+ maybe some gears)
- A box for this measuring tape
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can ii do it in less than a 3 weeks
processor unit. What would I, need to make these changes to increase the measuring capacity of your tape measure ?
How accurate is it?
OK, dumb question incoming (sorry, I have to ask it) but, 1 cm or 1 inch...? That's a big discrepancy. If you were talking about 1cm per 1/2 kilometer or 1 inch per 300 yards or something along that line, then it's not that big a deal. But, if it's less than that then I question the accuracy.
Can you be a little more specific about it's accuracy, please?
Thanks!
http://zone.ni.com/devzone/cda/tut/p/id/4763
By putting the encoders out of phase by 90 degrees you essentially quadruple the counts per turn. The old mouse should have 2 break beam sensors in it already.
I'll vote it !!