AttinyCZ1Synth.ino

// (*) All in the spirit of open-source and open-hardware
// Janost 2017 Sweden
// The 3HP Paperface Euro Modules
// https://janostman.wordpress.com/the-3hp-paperface-euro-modules/
// Copyright 2017 DSP Synthesizers Sweden.
//
// Author: Jan Ostman
//
// This program is free software: you can redistribute it and/or modify
//it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.

//Set Fuses to E1 DD FE for PLLCLK 16MHz

#include <avr/interrupt.h>

#include <avr/io.h>

#include <avr/pgmspace.h>

 

#ifndef cbi

#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))

#endif

#ifndef sbi

#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))

#endif

 

uint8_t phase;

uint8_t otone1;

uint8_t otone2;

 

volatile uint8_t level1;

volatile uint8_t PDmod;

 

volatile uint8_t level3;

volatile uint8_t level4;

volatile uint8_t level5;

 

uint8_t MUX;

volatile uint16_t pitch;

uint16_t phacc;

uint16_t pdacc;

uint8_t dac;

 

const uint8_t sinetable[256] PROGMEM = {

0,0,0,0,1,1,1,2,2,3,4,5,5,6,7,9,10,11,12,14,15,16,18,20,21,23,25,27,29,31,

33,35,37,39,42,44,46,49,51,54,56,59,62,64,67,70,73,76,78,81,84,87,90,93,96,99,102,105,108,111,115,118,121,124,

127,130,133,136,139,143,146,149,152,155,158,161,164,167,170,173,176,178,181,184,187,190,192,195,198,200,203,205,208,210,212,215,217,219,221,223,225,227,229,231,233,234,236,238,239,240,

242,243,244,245,247,248,249,249,250,251,252,252,253,253,253,254,254,254,254,254,254,254,253,253,253,252,252,251,250,249,249,248,247,245,244,243,242,240,239,238,236,234,233,231,229,227,225,223,

221,219,217,215,212,210,208,205,203,200,198,195,192,190,187,184,181,178,176,173,170,167,164,161,158,155,152,149,146,143,139,136,133,130,127,124,121,118,115,111,108,105,102,99,96,93,90,87,84,81,78,

76,73,70,67,64,62,59,56,54,51,49,46,44,42,39,37,35,33,31,29,27,25,23,21,20,18,16,15,14,12,11,10,9,7,6,5,5,4,3,2,2,1,1,1,0,0,0

};

 

const uint16_t SAMPLEfreq[1024] PROGMEM ={

1024,1027,1030,1034,1037,1041,1045,1048,1052,1055,1059,1062,1066,1070,1073,1077,

1080,1084,1088,1092,1095,1099,1103,1106,1110,1114,1118,1121,1125,1129,1133,1137,

1141,1145,1148,1152,1156,1160,1164,1168,1172,1176,1180,1184,1188,1192,1196,1200,

1204,1208,1212,1216,1221,1225,1229,1233,1237,1241,1246,1250,1254,1258,1263,1267,

1271,1275,1280,1284,1288,1293,1297,1302,1306,1310,1315,1319,1324,1328,1333,1337,

1342,1346,1351,1356,1360,1365,1369,1374,1379,1383,1388,1393,1398,1402,1407,1412,

1417,1421,1426,1431,1436,1441,1446,1451,1456,1460,1465,1470,1475,1480,1485,1490,

1495,1501,1506,1511,1516,1521,1526,1531,1537,1542,1547,1552,1557,1563,1568,1573,

1579,1584,1589,1595,1600,1606,1611,1617,1622,1628,1633,1639,1644,1650,1655,1661,

1667,1672,1678,1684,1689,1695,1701,1707,1712,1718,1724,1730,1736,1742,1747,1753,

1759,1765,1771,1777,1783,1789,1795,1802,1808,1814,1820,1826,1832,1839,1845,1851,

1857,1864,1870,1876,1883,1889,1895,1902,1908,1915,1921,1928,1934,1941,1947,1954,

1961,1967,1974,1981,1987,1994,2001,2008,2014,2021,2028,2035,2042,2049,2056,2063,

2070,2077,2084,2091,2098,2105,2112,2119,2127,2134,2141,2148,2156,2163,2170,2178,

2185,2192,2200,2207,2215,2222,2230,2237,2245,2253,2260,2268,2276,2283,2291,2299,

2307,2314,2322,2330,2338,2346,2354,2362,2370,2378,2386,2394,2402,2410,2419,2427,

2435,2443,2452,2460,2468,2477,2485,2493,2502,2510,2519,2527,2536,2545,2553,2562,

2571,2579,2588,2597,2606,2614,2623,2632,2641,2650,2659,2668,2677,2686,2695,2704,

2714,2723,2732,2741,2751,2760,2769,2779,2788,2798,2807,2817,2826,2836,2845,2855,

2865,2874,2884,2894,2904,2914,2923,2933,2943,2953,2963,2973,2983,2993,3004,3014,

3024,3034,3045,3055,3065,3076,3086,3097,3107,3118,3128,3139,3149,3160,3171,3182,

3192,3203,3214,3225,3236,3247,3258,3269,3280,3291,3302,3313,3325,3336,3347,3359,

3370,3381,3393,3404,3416,3428,3439,3451,3463,3474,3486,3498,3510,3522,3534,3546,

3558,3570,3582,3594,3606,3618,3631,3643,3655,3668,3680,3693,3705,3718,3730,3743,

3756,3768,3781,3794,3807,3820,3833,3846,3859,3872,3885,3898,3911,3924,3938,3951,

3965,3978,3991,4005,4019,4032,4046,4060,4073,4087,4101,4115,4129,4143,4157,4171,

4185,4199,4214,4228,4242,4257,4271,4286,4300,4315,4329,4344,4359,4373,4388,4403,

4418,4433,4448,4463,4478,4494,4509,4524,4539,4555,4570,4586,4601,4617,4633,4648,

4664,4680,4696,4712,4728,4744,4760,4776,4792,4808,4825,4841,4857,4874,4890,4907,

4924,4940,4957,4974,4991,5008,5025,5042,5059,5076,5093,5110,5128,5145,5162,5180,

5198,5215,5233,5251,5268,5286,5304,5322,5340,5358,5376,5395,5413,5431,5450,5468,

5487,5505,5524,5543,5562,5580,5599,5618,5637,5656,5676,5695,5714,5734,5753,5773,

5792,5812,5831,5851,5871,5891,5911,5931,5951,5971,5992,6012,6032,6053,6073,6094,

6114,6135,6156,6177,6198,6219,6240,6261,6282,6304,6325,6346,6368,6390,6411,6433,

6455,6477,6499,6521,6543,6565,6587,6609,6632,6654,6677,6700,6722,6745,6768,6791,

6814,6837,6860,6883,6907,6930,6954,6977,7001,7025,7049,7072,7096,7120,7145,7169,

7193,7217,7242,7267,7291,7316,7341,7366,7391,7416,7441,7466,7491,7517,7542,7568,

7593,7619,7645,7671,7697,7723,7749,7775,7802,7828,7855,7881,7908,7935,7962,7989,

8016,8043,8070,8098,8125,8153,8180,8208,8236,8264,8292,8320,8348,8377,8405,8433,

8462,8491,8520,8548,8577,8606,8636,8665,8694,8724,8753,8783,8813,8843,8873,8903,

8933,8963,8994,9024,9055,9085,9116,9147,9178,9209,9240,9272,9303,9335,9366,9398,

9430,9462,9494,9526,9559,9591,9624,9656,9689,9722,9755,9788,9821,9854,9888,9921,

9955,9989,10022,10056,10090,10125,10159,10193,10228,10263,10298,10332,10367,10403,10438,10473,

10509,10544,10580,10616,10652,10688,10724,10761,10797,10834,10871,10907,10944,10981,11019,11056,

11094,11131,11169,11207,11245,11283,11321,11360,11398,11437,11475,11514,11553,11593,11632,11671,

11711,11751,11790,11830,11871,11911,11951,11992,12032,12073,12114,12155,12196,12238,12279,12321,

12363,12404,12447,12489,12531,12574,12616,12659,12702,12745,12788,12832,12875,12919,12962,13006,

13051,13095,13139,13184,13228,13273,13318,13363,13409,13454,13500,13546,13591,13638,13684,13730,

13777,13823,13870,13917,13965,14012,14059,14107,14155,14203,14251,14299,14348,14396,14445,14494,

14543,14593,14642,14692,14742,14792,14842,14892,14943,14993,15044,15095,15146,15198,15249,15301,

15353,15405,15457,15509,15562,15615,15668,15721,15774,15828,15881,15935,15989,16043,16098,16152,

16207,16262,16317,16372,16428,16484,16540,16596,16652,16708,16765,16822,16879,16936,16993,17051,

17109,17167,17225,17283,17342,17401,17460,17519,17578,17638,17698,17758,17818,17878,17939,18000,

18061,18122,18184,18245,18307,18369,18431,18494,18557,18620,18683,18746,18810,18873,18937,19002,

19066,19131,19195,19261,19326,19391,19457,19523,19589,19656,19722,19789,19856,19924,19991,20059,

20127,20195,20264,20332,20401,20470,20540,20609,20679,20749,20820,20890,20961,21032,21104,21175,

21247,21319,21391,21464,21537,21610,21683,21756,21830,21904,21978,22053,22128,22203,22278,22353,

22429,22505,22582,22658,22735,22812,22889,22967,23045,23123,23201,23280,23359,23438,23518,23597,

23677,23758,23838,23919,24000,24081,24163,24245,24327,24410,24492,24575,24659,24742,24826,24910,

24995,25080,25165,25250,25336,25421,25508,25594,25681,25768,25855,25943,26031,26119,26208,26297,

26386,26475,26565,26655,26745,26836,26927,27018,27110,27202,27294,27387,27479,27573,27666,27760,

27854,27948,28043,28138,28234,28329,28425,28522,28619,28716,28813,28911,29009,29107,29206,29305,

29404,29504,29604,29704,29805,29906,30007,30109,30211,30313,30416,30519,30623,30727,30831,30935,

31040,31145,31251,31357,31463,31570,31677,31784,31892,32000,32109,32218,32327,32436,32546,32657

};

 

 

 

void setup() {

// Enable 64 MHz PLL and use as source for Timer1

PLLCSR = 1<<PCKE | 1<<PLLE;

 

// Set up Timer/Counter1 for PWM output

TIMSK = 0; // Timer interrupts OFF

TCCR1 = 1<<PWM1A | 2<<COM1A0 | 1<<CS10; // PWM A, clear on match, 1:1 prescale

//GTCCR = 1<<PWM1B | 2<<COM1B0; // PWM B, clear on match

OCR1A = 128; //OCR1B = 128; // 50% duty at start

 

pinMode(1, OUTPUT); // Enable PWM output pin

pinMode(2, INPUT);

 

// Set up Timer/Counter0 for 66979Hz interrupt to output samples.

TCCR0A = 3<<WGM00; // Fast PWM

TCCR0B = 1<<WGM02 | 2<<CS00; // 1/8 prescale

TIMSK = 1<<OCIE0A; // Enable compare match, disable overflow

OCR0A = 29; // 66979Hz

 

uint16_t dummy=analogRead(0);

}

 

void loop() {

if (digitalRead(2)) level1=255; //Test for Gate VCA

if (!digitalRead(2)) level1=0;

 

//————— ADC block ————————————-

if (!(ADCSRA & 64)) {

uint16_t level=((ADCL+(ADCH<<8)));

if (MUX==3) pitch=(pgm_read_word_near( SAMPLEfreq + level));

if (MUX==2) PDmod=(level>>3)+1;

MUX++;

MUX&=3;

ADMUX = MUX; //Select MUX

sbi(ADCSRA, ADSC); //start next conversation

}

//—————————————————————

}

ISR(TIMER0_COMPA_vect) {

phacc+=pitch;

if (phacc & 0x8000) {

phacc &= 0x7FFF;

otone1+=1;

uint8_t env=(255-otone1);

pdacc+=PDmod;

if (!otone1) pdacc=0;

otone2=(pdacc>>3)&255;

dac=((pgm_read_byte(&sinetable[otone2])+pgm_read_byte(&sinetable[(otone2+(127-env))&255]))>>1);

OCR1A = dac&level1; //Gate the signal

}

//—————————————————————–

}