Using a optical coder

[debutpic]

Hello all

In my new project I will use a optical coder for to know the position of tool (lathe)
Optical coder is a 300 pulses/turn
A full rotation of my lathe is equal 5 millimetres
A pulse >>> 1,6/100 millimeters


First problem
I dont' know how to write this piece of code currently I calculate only the integer,a starting point please?

[Darrel Taylor]

Hi debutpic,

Here's one way to do it.

Pulse_Rev  CON  300  ' Pulses per Rev
Dist_Rev   CON  500  ' Distance per Rev in mm*100
Position   VAR  WORD

Position = Compteur * Dist_Rev
Position = DIV32 Pulse_Rev

And, Ingvar will be along shortly to show you how to do it with "*/"
<br>

[debutpic]

he he It work fine Darrel !!

perhaps a another question,the optical coder has only one output TTL.
I count the pulses with the pin RB0/INT but how to know if it turns in a direction or the other?

[Darrel Taylor]

Unless you have some other way of knowing which way it's going, I don't think you can.

If it needs to keep track of absolute position in both directions, you'll probably need a "Quadrature Encoder".
<br>

[Ingvar]

I try hard not to ......

[debutpic]

Hello all

1) Which is the method of programming used for to know the directions of rotation with these optical coders?

2)the next opticals coders agree?

thank's