DIGITAL SPEEDOMETER

[Prateek]

I want to make a digital speedometer. Concept is to measure the rpm of
the wheel for say 5 sec. the revolutions will be counted by a counter.
After every 5 sec the count is latched and the counter is reset. the
latched count is fed to an EPROM which has the speed data fed in
depending upon the wheel diameter. the output is the corresponding
speed which is diplayed on 7 segment LED. Now my problem is HOW TO
GENERATE THE PULSES FOR RUNNING THE COUNTER? need help on this please

 

[BobG]

I want to make a digital speedometer.
Now my problem is HOW TO
GENERATE THE PULSES FOR RUNNING THE COUNTER? need help on this please

====================================
There is a vehicle speed sensor on the transmission. Splice into this
wire?

 

[feebo]

I want to make a digital speedometer. Concept is to measure the rpm of
the wheel for say 5 sec. the revolutions will be counted by a counter.
After every 5 sec the count is latched and the counter is reset. the
latched count is fed to an EPROM which has the speed data fed in
depending upon the wheel diameter. the output is the corresponding
speed which is diplayed on 7 segment LED. Now my problem is HOW TO
GENERATE THE PULSES FOR RUNNING THE COUNTER? need help on this please

what is it for? A bike, car, machine?

Can you mount some magnets on the wheel and a sensor for them going
past?

maybe some pieces of aluminum foil, and pick them up with an opto
transmitter/receiver.

Shine a light rhtough the spokes (IR?) and detect the spokes going
past with an ldr

 

[[email protected]]

I want to make a digital speedometer. Concept is to measure the rpm of
the wheel for say 5 sec. the revolutions will be counted by a counter.
After every 5 sec the count is latched and the counter is reset. the
latched count is fed to an EPROM which has the speed data fed in
depending upon the wheel diameter. the output is the corresponding
speed which is diplayed on 7 segment LED. Now my problem is HOW TO
GENERATE THE PULSES FOR RUNNING THE COUNTER? need help on this please

Go buy one of those boxes of cereal that include a bike speedometer.

http://groups.google.com/group/sci....1da0b91?q=cereal+bike&rnum=1#3fd09d2831da0b91

BTW, your project is begging for a microcontroller.

If your pulse rate is low (like for the bike), magnets and reed
switches are good. Magnets and coils or Hall sensors are better for
faster rates. Opto (reflection or transmission) has issues with dirt.

GG

 

[JeffM]

Prateek MULTI-POSTED:

I want to make a digital speedometer.

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