Search found 54 matches

by Aaron
Tue Aug 18, 2020 6:21 am
Forum: Algorithm development
Topic: Creating a Weaver type radio demodulator
Replies: 4
Views: 6839

Re: Creating a Weaver type radio demodulator

These are the equations I use:

s(n+1) = s(n) + fc * c(n)
c(n+1) = c(n) - fc * s(n+1)

fc = 2 * pi * f / R
f = frequency in Hz
R = sample rate in Hz
by Aaron
Mon Aug 17, 2020 5:18 am
Forum: Algorithm development
Topic: Creating a Weaver type radio demodulator
Replies: 4
Views: 6839

Re: Creating a Weaver type radio demodulator

There is a program called "Battling LFOs" on this page:
http://www.spinsemi.com/programs.php
It uses a coupled form oscillator to generate a sine and cosine. You can read more about this algo on this paper:
https://ccrma.stanford.edu/~dattorro/Ef ... nPart3.pdf
by Aaron
Wed Jan 22, 2020 9:20 am
Forum: Algorithm development
Topic: Algorithm for Modulated delay and tap tempo?
Replies: 1
Views: 5783

Re: Algorithm for Modulated delay and tap tempo?

If you search through the forum you will find all of the information you need.
by Aaron
Wed Mar 20, 2019 9:38 am
Forum: Algorithm development
Topic: Shimmer
Replies: 40
Views: 93302

Re: Shimmer

You can try adding some delay to pitchout before reading it back into the input...
by Aaron
Wed Feb 27, 2019 3:58 pm
Forum: FV-1 software questions
Topic: Anyone succesfully programming the FV-1 on a mac?
Replies: 11
Views: 9277

Re: Anyone succesfully programming the FV-1 on a mac?

... 2. I got cheap PICkit2 from aliexpress, it worked fine (I got PICkit3 from digikey, but it not working with serial EEPROM. I was disappointed and bought cheap replica of PICkit2). ... I have been able to get the PICkit3 to work with the 24lc32 with the help of this site. http://www.itsonlyaudio...
by Aaron
Mon Nov 12, 2018 12:12 pm
Forum: FV-1 software questions
Topic: Modulation Delay
Replies: 1
Views: 4121

Re: Modulation Delay

Something like this should work: mem del 31120 mem mod 1311 equ lpf reg0 skp run,1 wlds 0,12,239 ;init sin0 lfo ~0.5Hz ldax pot0 ;read pot0 sof 0.9,0.05 ;scale 50ms to 950ms rdfx lpf,0.001 ;low pass filter pot ~ 5Hz wrlx lpf,-1 ; wrax addr_ptr,0 ;save to address pointer rmpa 1 ;read sample from dela...
by Aaron
Tue Aug 21, 2018 6:37 am
Forum: Algorithm development
Topic: Fade In Help
Replies: 12
Views: 6835

Re: Fade In Help

As you have it now you are always executing "lowsignal". You may want to check how your skp statements are executing.
You are also multiplying your averaged signal instead of your input by the gain factor.
by Aaron
Tue Jul 17, 2018 8:29 am
Forum: Algorithm development
Topic: Idea - Audio ADC as a digital input
Replies: 6
Views: 6079

Re: Idea - Audio ADC as a digital input

I have used a similar technique to use the ADC as a fourth pot. For a digital type of input you would only need to determine whether the signal is present or not. I think doing a skp statement could be more appropriate: ldax adcr ;read input skp zro,STATE ;if switch is off, no signal is present, jum...
by Aaron
Fri Mar 30, 2018 6:57 am
Forum: Algorithm development
Topic: Tone Control
Replies: 12
Views: 9768

Input, Filter, and K were all just used for the sake of example. "Input" should be whatever register you are using for the input to the filter, "Filter" is whatever you want to call your lpf, and "K" is whatever you want to call the cutoff frequency coefficient. In orde...
by Aaron
Thu Mar 29, 2018 10:45 am
Forum: Algorithm development
Topic: Tone Control
Replies: 12
Views: 9768

The combination of RDFX and WRAX creates a simple lpf. In order to modulate the cutoff frequency we need to deconstruct RDFX. Looking at the block diagram of RDFX: http://www.spinsemi.com/images/knowledge_base_img/INST_RDFX.jpg and assuming the input of the filter is in ACC, we see that RDFX perfoms...
by Aaron
Thu Mar 29, 2018 10:10 am
Forum: Algorithm development
Topic: Tone Control
Replies: 12
Views: 9768

This implementation is a shelving filter. You may want to take a look at the input of the filter to make sure you are reading the proper register.
by Aaron
Thu Mar 29, 2018 9:49 am
Forum: Algorithm development
Topic: Tone Control
Replies: 12
Views: 9768

No need to apologize for asking a question! You should start by reading though the knowledge base, particularly this section on low pass filters. It explains the behavior of the algorithm and provides the formula for the cutoff frequency. You should also take a look at the instructions and syntax fo...
by Aaron
Wed Aug 02, 2017 6:40 am
Forum: Algorithm development
Topic: Tap Tempo tremolo again
Replies: 9
Views: 12590

Log rules dictate that: log(a/b) = log(a)-log(b) and log(a*b) = log(a)+log(b) so for (8*pi)/x we can re-write this as: exp ( log( 8 )+log( pi )-log( x ) ) in spin terms this would look like: ldax x ;load x in acc log -1,0.29 ; ( logbase2(x) / 16 ) * -1 + ( logbase2(8*pi) / 16 ) exp 1,0 ; 2^(acc*16)
by Aaron
Tue Jun 27, 2017 7:21 am
Forum: Algorithm development
Topic: Adjusting reverb algorithms against changes in sample rate
Replies: 2
Views: 4598

I haven't tried this at all, but it would seem that you could use the address pointer and rmpa instead of rda from the end of the delay space. It would definitely take up more code but it should work.
by Aaron
Wed Mar 08, 2017 3:44 pm
Forum: FV-1 hardware questions
Topic: 3 Programs with an SPDT ON-OFF-ON Switch
Replies: 5
Views: 6300

That looks like it will do the trick. This should give you access to programs 0-2.