[PIC] School Help RPM counter

First of all I'm from portugal so sorry if I misspell something

Hello there I'm involved In a school project, and I searched the web to see if someone could help me develop a program that is basicaly a rpm counter that inputs the results into a lcd screen like this

**broken link removed**.

In my school we use Picaxe 28x2 and picaxe editor 6 as our programming software.

I already took out a sensor of a printer and figured out that it is light sensitive. So I attached white paper to a wheel with a black stripe, so when the black stripe hits the sensor it should count a rotation.

Can someone from this concept help me create a program? It would be awesome. :!:

Thanks in advance

P.S. I know you might need the exact tension values but just work with a generic number, for example 5 volts normally, down to 1v when the black stripe crosses the sensor.

Ruben Gomes :razz:

Hi,

Give us some more information:
What is your disired max. Rpm to disply?
What is your desired resolution of rpm?
How often do you like to update your display?

Hint:
Usually you wait a known fixed time and count the pulses. Then calculate rpm by: counts/time

With low rpm one waits for a rising edge of sensor signal and measures the time to the next rising edge.
Calculation: rpm = 1 / time

Mind to always use the correct units

Klaus

KlausST said:

Hi,

Give us some more information:
What is your disired max. Rpm to disply?
What is your desired resolution of rpm?
How often do you like to update your display?

Hint:
Usually you wait a known fixed time and count the pulses. Then calculate rpm by: counts/time

With low rpm one waits for a rising edge of sensor signal and measures the time to the next rising edge.
Calculation: rpm = 1 / time

Mind to always use the correct units

Klaus

Click to expand...

I chose to take a diferent route and use an arduino i got this setup: https://duino4projects.com/wp-content/uploads/2013/05/Arduino-RPM-Counter.gif

the potentiometer is just to regulate the display brightness.