296 lines
8.6 KiB
Plaintext
296 lines
8.6 KiB
Plaintext
#include <stdint.h>
|
|
#include <stdlib.h>
|
|
#include "DFT8Turbo.h"
|
|
#include <math.h>
|
|
|
|
#include <stdio.h>
|
|
|
|
#define MAX_FREQS (24)
|
|
#define OCTAVES (5)
|
|
|
|
|
|
/*
|
|
* The first thought was using an integration map and only operating when we need to, to pull the data out.
|
|
* Now we're doing the thing below this block comment
|
|
int16_t accumulated_total; //2 bytes
|
|
int16_t last_accumulated_total_at_bin[MAX_FREQS*2]; //24 * 2 * sizeof(int16_t) = 96 bytes.
|
|
uint8_t current_time; //1 byte
|
|
uint8_t placecode[MAX_FREQS];
|
|
*/
|
|
//OK... We don't have enough ram to sum everything... can we do something wacky with multiple ocatives to sum everything better?
|
|
//i.e.
|
|
//
|
|
// 4332322132212210
|
|
//
|
|
// ++++++++++++++++-----------------
|
|
// ++++++++--------
|
|
// ++++----++++----
|
|
// ++--++--++--++--
|
|
// +-+-+-+-+-+-+-+-
|
|
//
|
|
// Don't forget we need to do this for sin and cos.
|
|
// Can we instead of making this plusses, make it a multiplier?
|
|
// How can we handle sin+cos?
|
|
//
|
|
// Is it possible to do this for every frame? I.e. for each of the 24 notes, multiply with their current place in table?
|
|
// That's interesting. It's not like a sin table.
|
|
// There is no "multiply" in the attiny instruction set for attiny85.
|
|
// There is, however for attiny402
|
|
|
|
//Question: Can we do five octaves, or does this need to be balanced?
|
|
//Question2: Should we weight higher octaves?
|
|
|
|
|
|
//ATTiny402: 256x8 RAM, 4096x8 FLASH LPM: 3 cycles + FMUL: 2 cycles << Do stacked sin waves?
|
|
//ATtiny85: 512x8 RAM, 8192x8 FLASH LPM: 3 cycles + NO MULTIPLY << Do square waves?
|
|
|
|
|
|
/* Approaches:
|
|
|
|
on ATtiny402: Stacked sin approach.
|
|
Say 16 MHz, though 12 MHz is interesting...
|
|
16k SPS: 1k cycles per; say 24 bins per; 41 cycles per bin = hard. But is it too hard?
|
|
20 cycles per s/c.
|
|
read place in stacked table (8? bits) 3 cycles
|
|
|
|
//Inner loop = 17 cycles.
|
|
read stacked table (8 bits), 3 cycles
|
|
fractional multiply table with current value. 2 cycles
|
|
read current running for note 2 cycles (LDS = 3 cycles)
|
|
subtract a shifted version, to make it into an IIR. (4 cycles)
|
|
add in current values. (2 cycles)
|
|
store data back to ram (2 cycles)
|
|
advance place in stacked table (8?bits) 1 cycle
|
|
|
|
store place in stacked table (8? bits) 3 cycles?
|
|
|
|
//What if we chunk ADC updates into groups of 4 or 8?
|
|
//This is looking barely possible.
|
|
|
|
on attiny85: scheduled adds/subtracts (like a stacked-square-wave-table)
|
|
//XXX TODO!
|
|
|
|
*/
|
|
|
|
/* Ok... Let's think about the ATTiny402. 256x8 RAM + 4096x8 FLASH.
|
|
|
|
* We can create a table which has all octaves overlaid.
|
|
* We would need to keep track of:
|
|
* 12 x 2 x 2 = 48 bytes = Current sin/cos values.
|
|
* 12 x 2 = 24 bytes = Current place in table. = 72 bytes
|
|
* We would need to store:
|
|
* The layered lookup table. If possible, keep @ 256 bytes to simplify math ops.
|
|
* The speed by which each note needs to advance.
|
|
* We would need to:
|
|
* Read current running place. X 8 cycles
|
|
* Use that place to look up into sin table. 3 cycles
|
|
* Read running val 4 cycles best case
|
|
* Multiply out the sin + IIR 5 cycles
|
|
* Store running val 4 cycles best case
|
|
* Cos-advance that place to look up into sin table. 4 cycles
|
|
* Read running val 4 cycles best case
|
|
* Multiply out the sin + IIR 5 cycles
|
|
* Store running val 4 cycles best case.
|
|
* Read how much to advance X by. 4 cycles
|
|
* (Cos^2+Sin^2) 8?
|
|
* Store it. 4 cycles best case.
|
|
* = 48 x 12 = 576 cycles. Assume 10 MHz @ 16k SPS. We're OK (625 samples)
|
|
*/
|
|
|
|
// Observation: The two tables are actually mirror images of each other, well diagonally mirrored. That's odd. But, would take CPU to exploit.
|
|
|
|
#define SSTABLESIZE 256
|
|
int8_t spikysin_interleved_cos[SSTABLESIZE][2];
|
|
uint32_t advancespeed[MAX_FREQS];
|
|
|
|
static int CompTableWithPhase( int nelements, float phase, int scaling )
|
|
{
|
|
int highest = 0;
|
|
int i;
|
|
for( i = 0; i < nelements; i++ )
|
|
{
|
|
float taued = i * 3.141592 * 2.0 / nelements;
|
|
int o;
|
|
float combsin = 0;
|
|
for( o = 0; o < OCTAVES; o++ )
|
|
{
|
|
combsin += sin( taued * (1<<o) + phase);
|
|
}
|
|
combsin /= OCTAVES;
|
|
int csadapt = combsin * scaling - 0.5; //No value is higher with five octaves. XXX TODO Lookout. If you change # of octaves, need to change this, too.
|
|
|
|
if( csadapt > highest ) highest = csadapt;
|
|
if( -csadapt > highest ) highest = -csadapt;
|
|
|
|
if( csadapt > 127 ) csadapt = 127;
|
|
if( csadapt < -128 ) csadapt = -128; //tricky: Keep balanced.
|
|
spikysin_interleved_cos[i][0] = csadapt;
|
|
|
|
float combcos = 0;
|
|
for( o = 0; o < OCTAVES; o++ )
|
|
{
|
|
combcos += cos( taued * (1<<o) + phase );
|
|
}
|
|
combcos /= OCTAVES;
|
|
csadapt = combcos * scaling - 0.5; //No value is higher with five octaves. XXX TODO Lookout. If you change # of octaves, need to change this, too.
|
|
|
|
if( csadapt > highest ) highest = csadapt;
|
|
if( -csadapt > highest ) highest = -csadapt;
|
|
|
|
if( csadapt > 127 ) csadapt = 127;
|
|
if( csadapt < -128 ) csadapt = -128; //tricky: Keep balanced.
|
|
spikysin_interleved_cos[i][1] = csadapt;
|
|
}
|
|
return highest;
|
|
}
|
|
|
|
|
|
static int Setup( float * frequencies, int bins )
|
|
{
|
|
int i;
|
|
|
|
//Since start position/phase is arbitrary, we should try several to see which gives us the best dynamic range.
|
|
float tryphase = 0;
|
|
|
|
float bestphase = 0;
|
|
int highest_val_at_best_phase = 1000000;
|
|
|
|
for( tryphase = 0; tryphase < 3.14159; tryphase += 0.001 )
|
|
{
|
|
int highest = CompTableWithPhase( SSTABLESIZE, tryphase, 65536 );
|
|
if( highest < highest_val_at_best_phase )
|
|
{
|
|
highest_val_at_best_phase = highest;
|
|
bestphase = tryphase;
|
|
}
|
|
}
|
|
printf( "Best comp: %f : %d\n", bestphase, highest_val_at_best_phase );
|
|
|
|
//Set this because we would overflow the sinm and cosm regs if we don't. This is sort of like a master volume.
|
|
//use this as that input volume knob thing.
|
|
float further_reduce = 1.0;
|
|
|
|
CompTableWithPhase( SSTABLESIZE, bestphase, (65536*128*further_reduce)/highest_val_at_best_phase );
|
|
|
|
// for( i = 0; i < SSTABLESIZE; i++ )
|
|
// {
|
|
// printf( "%d %d\n", spikysin_interleved_cos[i*2+0], spikysin_interleved_cos[i*2+1] );
|
|
// }
|
|
|
|
for( i = 0; i < MAX_FREQS; i++ )
|
|
{
|
|
//frequencies[i] = SPS / Freq
|
|
// Need to decide how quickly we sweep through the table.
|
|
advancespeed[i] = 65536 * 256.0 /* fixed point */ * 256.0 /* size of table */ / frequencies[i];
|
|
//printf( "%f\n", frequencies[i] );
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
/*
|
|
uint8_t spikysin_interleved_cos[256*2];
|
|
uint16_t advancespeed[MAX_FREQS];
|
|
*/
|
|
|
|
float toutbins[MAX_FREQS];
|
|
|
|
struct notedat
|
|
{
|
|
uint32_t time;
|
|
int32_t sinm;
|
|
int32_t cosm;
|
|
};
|
|
|
|
static struct notedat nd[MAX_FREQS];
|
|
|
|
void Turbo8BitRun( int8_t adcval )
|
|
{
|
|
int i;
|
|
for( i = 0; i < MAX_FREQS; i++ )
|
|
{
|
|
uint32_t ct = nd[i].time;
|
|
int32_t muxres;
|
|
int32_t running;
|
|
int32_t rdesc, rdess;
|
|
uint8_t * spikysintable = &spikysin_interleved_cos[(ct>>24)][0];
|
|
|
|
int8_t ss = *(spikysintable++);
|
|
|
|
#define DECIR 8
|
|
|
|
muxres = ((int16_t)adcval * ss + (1<<(DECIR-1)) ) >> (DECIR);
|
|
running = nd[i].cosm;
|
|
running += muxres;
|
|
rdesc = running >> 8;
|
|
running -= rdesc >> 3;
|
|
|
|
nd[i].cosm = running;
|
|
if( i == 0) printf( "MRX %5d %9d %9d %9d %9d\n", muxres, adcval, ss, running, nd[i].sinm );
|
|
int8_t sc = *(spikysintable++);
|
|
muxres = ((int16_t)adcval * sc + (1<<(DECIR-1)) ) >> (DECIR);
|
|
running = nd[i].sinm;
|
|
running += muxres;
|
|
|
|
rdess = running>>8;
|
|
running -= rdess >> 3;
|
|
|
|
nd[i].sinm = running;
|
|
|
|
nd[i].time = ct + advancespeed[i];
|
|
|
|
toutbins[i] = rdess * rdess + rdesc * rdesc;
|
|
//printf( "%d %d = %f %p\n", rdess, rdesc, toutbins[i], &toutbins[i] );
|
|
}
|
|
|
|
static uint8_t stater;
|
|
/* stater++;
|
|
if( stater == 16 )
|
|
{
|
|
stater = 0;
|
|
for( i = 0; i < MAX_FREQS; i++ )
|
|
{
|
|
nd[i].sinm -= nd[i].sinm >> 12;
|
|
nd[i].cosm -= nd[i].cosm >> 12;
|
|
nd[i].sinm += 8;
|
|
nd[i].cosm += 8;
|
|
}
|
|
}*/
|
|
}
|
|
|
|
|
|
void DoDFT8BitTurbo( float * outbins, float * frequencies, int bins, const float * databuffer, int place_in_data_buffer, int size_of_data_buffer, float q, float speedup )
|
|
{
|
|
static int is_setup;
|
|
if( !is_setup ) { is_setup = 1; Setup( frequencies, bins ); }
|
|
static int last_place;
|
|
int i;
|
|
|
|
for( i = last_place; i != place_in_data_buffer; i = (i+1)%size_of_data_buffer )
|
|
{
|
|
int16_t ifr1 = (int16_t)( ((databuffer[i]) ) * 4095 );
|
|
//ifr1 += 4095;
|
|
//ifr1 += 512;
|
|
Turbo8BitRun( ifr1>>5 ); //6 = Actually only feed algorithm numbers from -64 to 63.
|
|
}
|
|
last_place = place_in_data_buffer;
|
|
|
|
for( i = 0; i < bins; i++ )
|
|
{
|
|
outbins[i] = 0;
|
|
}
|
|
for( i = 0; i < MAX_FREQS; i++ )
|
|
{
|
|
int iss = nd[i].sinm>>8;
|
|
int isc = nd[i].cosm>>8;
|
|
int mux = iss * iss + isc * isc;
|
|
if( mux == 0 ) mux = 1;
|
|
if( i == 0 )
|
|
printf( "MUX: %d %d\n", isc, iss );
|
|
outbins[i+MAX_FREQS] = sqrt(mux)/200.0;
|
|
}
|
|
|
|
}
|
|
|
|
|