Search found 25 matches
- Tue Apr 11, 2023 8:19 am
- Forum: Algorithm development
- Topic: Scales and Arpeggios
- Replies: 1
- Views: 6357
Scales and Arpeggios
Some programs of mine for producing scales and arpeggios. ; Ascending Major Scale (Ionian Mode) by Alex Lawrow ; ================================================== ; ; The note produced by each pitch-shifter is fed into a delay line. ; The output of which is used to feed the next pitch-shifter. ; ; ...
- Wed Apr 08, 2020 7:54 am
- Forum: Algorithm development
- Topic: Pitch Shifter: crossfade frequency
- Replies: 7
- Views: 10236
Re: Pitch Shifter: crossfade frequency
You can't eliminate it. Larry's explanation in terms of comb filter is spot on. As posted on this forum before (Don Stavely I think), you can reduce the frequency of the tremolo at the expense of increased latency. For example, if you are pitch-shifting by an octave, rather than do that in one step,...
- Wed Apr 08, 2020 7:42 am
- Forum: FV-1 software questions
- Topic: SPN file to Arduino
- Replies: 6
- Views: 10685
Re: SPN file to Arduino
Look at what I posted here... https://www.diystompboxes.com/smfforum/index.php?topic=121408.msg1156740#msg1156740 Included in the zip is the Arduino program to write to EEPROM and instructions on how to use with output from SpinASM. Note that to use it you must make SpinASM output a header file, rat...
- Sun Mar 22, 2020 8:06 am
- Forum: FV-1 software questions
- Topic: DSP What is a program? (& Linux IDE?)
- Replies: 6
- Views: 8959
Re: DSP What is a program? (& Linux IDE?)
If you are on Linux (or mac) there is a Python based assembler on github.
http://www.spinsemi.com/forum/viewtopic.php?t=680#p3606
You just need to make sure you use the spin compatibility flag (-s) command line option.
http://www.spinsemi.com/forum/viewtopic.php?t=680#p3606
You just need to make sure you use the spin compatibility flag (-s) command line option.
- Wed Apr 24, 2019 7:25 am
- Forum: Algorithm development
- Topic: log/exp exact coefficients
- Replies: 7
- Views: 9938
Re: log/exp exact coefficients
According to info in the manual, the log function maps to S4.19 so if the ACC has anything smaller than 0.00001526 is will presumably map to -16 by the log() operation. In other words, it seems the log() function isn't going to work on the bottom 8 bits of the 24 bits in the ACC. I am assuming those...
- Wed Apr 10, 2019 2:32 pm
- Forum: FV-1 software questions
- Topic: EEPROM memory map quest and I2C tips
- Replies: 5
- Views: 6466
Re: EEPROM memory map quest and I2C tips
I used an Arduino program to write FV-1 programs to EEPROM as part of a DIY project.
The EEPROM burner is part of the zip file here
https://1drv.ms/u/s!AvrH61utWEtEinTuwzdgxpn2TVm8
The EEPROM burner is part of the zip file here
https://1drv.ms/u/s!AvrH61utWEtEinTuwzdgxpn2TVm8
- Wed Apr 10, 2019 12:13 am
- Forum: FV-1 software questions
- Topic: Help. Noise at power up.
- Replies: 6
- Views: 5065
Re: Help. Noise at power up.
Increasing cap to 33pF solved it. Thanks.
When I first tried increasing the cap value I didn't increase it by a large enough value.
30pF didn't solve the problem but 33pF did.
When I first tried increasing the cap value I didn't increase it by a large enough value.
30pF didn't solve the problem but 33pF did.
- Tue Apr 09, 2019 4:08 am
- Forum: FV-1 software questions
- Topic: Division with FV-1
- Replies: 1
- Views: 3040
Re: Division with FV-1
To evaluate y = A / B on the FV-1 you evaluate this y = exp( log(A) - log(B) ) The problem is that the FV-1 log() only works on values in the range 0 to 1, and the exp() function only produces values in the range 0 to 1. This means that you need to make sure that the final answer lies in the range 0...
- Mon Apr 08, 2019 12:28 pm
- Forum: Algorithm development
- Topic: Calculating 1/(1+x) on the FV-1
- Replies: 1
- Views: 3582
Re: Calculating 1/(1+x) on the FV-1
I should have just looked on the Spin knowledge base. There is a much easier way.
1/(1+9x) with x = 0 to 1
= 0.1 / (0.1 + 0.9x)
= exp( log(0.1) - log(0.1+0.9x) )
No need for fancy approximations
1/(1+9x) with x = 0 to 1
= 0.1 / (0.1 + 0.9x)
= exp( log(0.1) - log(0.1+0.9x) )
No need for fancy approximations
- Mon Apr 08, 2019 1:33 am
- Forum: Algorithm development
- Topic: Reducing the tremolo artefact from pitch shifting
- Replies: 9
- Views: 7777
Re: Reducing the tremolo artefact from pitch shifting
Regarding square x-fade. Are you suggesting to make the two weighting functions intersect each other at a level not equal to 0.5 ? I can understand that instead of averaging voltage levels (V) you may want to average power levels (V^2) instead. That makes sense to me if the 2 signals are not correla...
- Mon Apr 08, 2019 1:17 am
- Forum: Algorithm development
- Topic: Triangle wave from sin LFO
- Replies: 8
- Views: 11160
Re: Triangle wave from sin LFO
Thanks for the code snippet.
- Sun Apr 07, 2019 7:10 am
- Forum: Algorithm development
- Topic: Reducing the tremolo artefact from pitch shifting
- Replies: 9
- Views: 7777
Re: Reducing the tremolo artefact from pitch shifting
I tried the diffusion but it didn't really help. I am not sure how much benefit comes from using sine weighting instead of linear increasing/decreasing weights. The mix ratios for the two read pointers will still cycle between (1 : 0), (0.5 : 0.5), (0, 1). I am assuming those 3 mix ratios correspond...
- Fri Apr 05, 2019 4:07 am
- Forum: Algorithm development
- Topic: Triangle wave from sin LFO
- Replies: 8
- Views: 11160
Triangle wave from sin LFO
Here's something I came up with which might be useful if the ramp LFOs are being used for something else. You can get a good approximation to a triangle wave using this formula ( 1 - abs(sin(t)) ) ^ 0.564476 The power is chosen to give best linearity based on the value at the halfway point. Due to t...
- Wed Apr 03, 2019 9:54 am
- Forum: Algorithm development
- Topic: EQD Aferneath
- Replies: 4
- Views: 10997
Re: EQD Aferneath
Looking at online images of the gutshots of that pedal you can tell that the top three controls map to the FV-1 pots. The other control pots are external to the FV-1. If they are externally modifying the clock rate to produce the "drag" effect then they are not using a crystal to clock the...
- Tue Apr 02, 2019 11:38 pm
- Forum: Algorithm development
- Topic: Knob variable power function?
- Replies: 4
- Views: 7911
Re: Knob variable power function?
Raise to power between 1 and 5
Code: Select all
;ACC contains something between 0 and 1
LOG 1,0
WRAX temp,1
SOF -2,0
SOF -2,0
MULX POT0
RDAX temp,1
EXP 1,0