Make an acceleration/deceleration ramp : any ideas?

[pxidr84]

I don't know how fast your ramp needs to be - but..

I would use a timer interrupt - say 1 millisecond

Multiply ramp time (in seconds) X 1000 to get the number of steps
Take

(endvalue - startvalue)/numberofsteps to get step size
Initialize a counter with the start value and increment the step size in each interrupt.

Depending on your needs, you may have to add some extra increments, because the step size will be an integer, and when multiplied by the number of steps may not exactly equal the
end value.

My maximum acceleration slope is incrementing a variable from 0 to 1200 in one second with a resolution of 1 (steps of 1).

I've tried to "translate" your algorithm into this :


'Variable init
freq var word
maxfreq var word
minfreq var word
stepnum var word
stepsize var word
time var word

'Variables def
minfreq=10
maxfreq=1200
time=10

'Calculate steps
stepnum=time*1000
stepsize=(maxfreq-minfreq)/stepnum

'Init counter
freq=minfreq

main:

' Counter
freq=freq+stepsize

'Update LCD
lcdout $fe,$2,"Frequency: ",dec5 freq

' 1ms time base (simulates an interrupt)
pause 1

goto main


It is correct? Because the result of "stepsize" is a float in this case (0.119)...