Looper / "sound on sound"

Algorithm development and general DSP issues

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soundsubs
Posts: 24
Joined: Fri Feb 25, 2011 11:49 am

Looper / "sound on sound"

Post by soundsubs »

im trying to use what i learned in the frzzer program to make a "sound on sound" looper which simply takes the input and replays it forever.
stealing appropriately from the program before, i tried...
but its not making sound. do i need to make a counter that writes at the step of memory it recorded at?

Code: Select all

; This program will record sound and Loop it infinitely, 
; constantly acquiring new input and adding it over the top.
; Loop length is based on the POT1 value
; 
delL mem 31233       	; Define delay as maximum 
ldax adcl       		; Read in ADC left 
wra delL,1.0       		; Write to left delay line 
wrax dacl,0       		; and to DAC left 
; Playing out the left input
play: 
clr 			; Clear ACC 
rdax   pot1,1       		; Read value of POT1, multiply by 1 to get a positive integer
mulx   pot1		; multiply the value in POT1 by itself
mulx   pot1		; multiply the value by itself again
and   %01111111_10000000_00000000 
sof  240/256,1/31233	; divide that into increments
wrax   addr_ptr,0 
rmpa 1               		; Read from address pointer 
wra delL,1.0       		; Write to head of delay 
wrax dacl,0       		; Write it to DAC left 
; 
end:



slacker
Posts: 116
Joined: Tue Feb 01, 2011 1:13 pm

Post by slacker »

Have a look at the guitar echo here for ideas http://www.spinsemi.com/forum/viewtopic.php?t=124 , if you set it to maximum feedback it does what you're trying to do.
soundsubs
Posts: 24
Joined: Fri Feb 25, 2011 11:49 am

Post by soundsubs »

Youre right, slacker, that is a good one.
i want to mod it so that it is ONLY infinite repeat, perhaps making POT0 control the ON/OFF of that infinite repeat.
also, i wouldnt mind seeing something like the 8 second delay available as well, although with degraded quality.

i'll post back if i figure it out.
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