frequency synth

letonton

hi all
fr. synth code is fine...
but if i want to obtain more than two frequencies
??
(i tried with more cogs - no result !)

and is it possible to change the output duty cycle ?
have precise width pulses ?

Microcontrolled

Are you sure that you started each cog that you tryed it on successfully?? I am not very experienced with the operation of cogs but if you did not start the cog than the program would not run correctly on it. It might just not be possible with that kind of object to create more than 2 frequencies. I am sorry if this does not help, but could you make it more clear of what you are trying to do?

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Toys are microcontroled.
Robots are microcontroled.
I am microcontrolled.

letonton

thanks
i just want (minimum) have 4 different frequencies
on 4 separate output pins...

and if possible change the duty cycle of signal...

Microcontrolled

This is a problem... You can try to modify the existing object in order to allow the 4 frequincies instead of 2.

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Toys are microcontroled.
Robots are microcontroled.
I am microcontrolled.

Beau Schwabe

letonton,

Since the counters are involved, you can only have 2 frequencies per cog, which means you need 2 cogs for your 4 frequencies. Here is some example code.

To change the Duty Cycle, you need to make modifications to the "Synth" object and follow the Application notes for using the PWM feature of the counters.

CON
  _clkmode = xtal1 + pll16x
  _xinfreq = 5_000_000


Pin1 = 0 
Pin2 = 1
Pin3 = 2
Pin4 = 3

F1 =  300
F2 =  500
F3 =  700
F4 = 1100

OBJ
  Freq    : "Synth"

VAR
long    Stack1[noparse][[/noparse]20]
long    Stack2[noparse][[/noparse]20]

PUB DEMO
    cognew(One_COG, @Stack1)
    cognew(Another_COG, @Stack2)    

PUB One_COG
  Freq.Synth("A", Pin1, F1)
  Freq.Synth("B", Pin2, F2)
  repeat  
      
PUB Another_COG
  Freq.Synth("A", Pin3, F3)
  Freq.Synth("B", Pin4, F4)
  repeat  

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Beau Schwabe

IC Layout Engineer
Parallax, Inc.

Post Edited (Beau Schwabe (Parallax)) : 4/22/2009 8:24:01 PM GMT

letonton

first
thanks to beau s. for help to a propeller and
spin beginner !

another question

if i want to run say some cogs, with some ready objects
(exemple : vga text and tv text objects) mixed with
a routine of my own (started with cognew) ?

also
i'd like a plot routine like this :

plot ( x, y, color)
where color is the pixel color value in a useful RGB form,
(4 intensity levels are enough)

thank you for help !