APRSuino/include/afsk_sinus.hpp

#include <avr/pgmspace.h>

#define BAUD 1200
#define BAUD_MARK 1200
#define BAUD_SPACE 2200
#define INV_BAUD 833
#define N_SHIFTS 6
#define N_SINUS_1200 833
#define N_SINUS_2200 454
#define SKEW_ROUNDS 3

const PROGMEM uint8_t SINUS1200[] = { 128, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 176, 177, 178, 179, 180, 181, 182, 183, 183, 184, 185, 186, 187, 188, 189, 189, 190, 191, 192, 193, 194, 194, 195, 196, 197, 198, 199, 199, 200, 201, 202, 202, 203, 204, 205, 206, 206, 207, 208, 209, 209, 210, 211, 212, 212, 213, 214, 214, 215, 216, 217, 217, 218, 219, 219, 220, 221, 221, 222, 223, 223, 224, 224, 225, 226, 226, 227, 228, 228, 229, 229, 230, 230, 231, 232, 232, 233, 233, 234, 234, 235, 235, 236, 236, 237, 237, 238, 238, 239, 239, 240, 240, 241, 241, 242, 242, 242, 243, 243, 244, 244, 245, 245, 245, 246, 246, 246, 247, 247, 247, 248, 248, 248, 249, 249, 249, 250, 250, 250, 250, 251, 251, 251, 251, 252, 252, 252, 252, 253, 253, 253, 253, 253, 254, 254, 254, 254, 254, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 254, 254, 254, 254, 254, 254, 254, 253, 253, 253, 253, 253, 253, 252, 252, 252, 252, 251, 251, 251, 251, 250, 250, 250, 250, 249, 249, 249, 248, 248, 248, 247, 247, 247, 246, 246, 246, 245, 245, 244, 244, 244, 243, 243, 242, 242, 241, 241, 241, 240, 240, 239, 239, 238, 238, 237, 237, 236, 236, 235, 235, 234, 234, 233, 233, 232, 231, 231, 230, 230, 229, 229, 228, 227, 227, 226, 226, 225, 224, 224, 223, 222, 222, 221, 220, 220, 219, 218, 218, 217, 216, 216, 215, 214, 213, 213, 212, 211, 211, 210, 209, 208, 208, 207, 206, 205, 205, 204, 203, 202, 201, 201, 200, 199, 198, 197, 197, 196, 195, 194, 193, 193, 192, 191, 190, 189, 188, 187, 187, 186, 185, 184, 183, 182, 181, 181, 180, 179, 178, 177, 176, 175, 174, 173, 173, 172, 171, 170, 169, 168, 167, 166, 165, 164, 163, 162, 162, 161, 160, 159, 158, 157, 156, 155, 154, 153, 152, 151, 150, 149, 148, 147, 146, 145, 144, 144, 143, 142, 141, 140, 139, 138, 137, 136, 135, 134, 133, 132, 131, 130, 129, 128, 127, 126, 125, 124, 123, 122, 121, 120, 119, 118, 118, 117, 116, 115, 114, 113, 112, 111, 110, 109, 108, 107, 106, 105, 104, 103, 102, 101, 100, 99, 98, 98, 97, 96, 95, 94, 93, 92, 91, 90, 89, 88, 87, 86, 86, 85, 84, 83, 82, 81, 80, 79, 78, 77, 77, 76, 75, 74, 73, 72, 71, 70, 70, 69, 68, 67, 66, 65, 64, 64, 63, 62, 61, 60, 59, 59, 58, 57, 56, 55, 55, 54, 53, 52, 51, 51, 50, 49, 48, 48, 47, 46, 45, 45, 44, 43, 42, 42, 41, 40, 40, 39, 38, 38, 37, 36, 36, 35, 34, 34, 33, 32, 32, 31, 30, 30, 29, 28, 28, 27, 27, 26, 25, 25, 24, 24, 23, 23, 22, 22, 21, 20, 20, 19, 19, 18, 18, 17, 17, 16, 16, 15, 15, 15, 14, 14, 13, 13, 12, 12, 12, 11, 11, 10, 10, 10, 9, 9, 8, 8, 8, 7, 7, 7, 6, 6, 6, 6, 5, 5, 5, 4, 4, 4, 4, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 8, 8, 8, 9, 9, 10, 10, 10, 11, 11, 12, 12, 12, 13, 13, 14, 14, 15, 15, 15, 16, 16, 17, 17, 18, 18, 19, 19, 20, 20, 21, 22, 22, 23, 23, 24, 24, 25, 25, 26, 27, 27, 28, 28, 29, 30, 30, 31, 32, 32, 33, 34, 34, 35, 36, 36, 37, 38, 38, 39, 40, 40, 41, 42, 42, 43, 44, 45, 45, 46, 47, 48, 48, 49, 50, 51, 51, 52, 53, 54, 55, 55, 56, 57, 58, 59, 59, 60, 61, 62, 63, 64, 64, 65, 66, 67, 68, 69, 70, 70, 71, 72, 73, 74, 75, 76, 77, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 118, 119, 120, 121, 122, 123, 124, 125, 126 };
const PROGMEM uint8_t SINUS2200[] = { 128, 129, 131, 133, 135, 136, 138, 140, 142, 143, 145, 147, 149, 150, 152, 154, 156, 157, 159, 161, 162, 164, 166, 168, 169, 171, 173, 174, 176, 177, 179, 181, 182, 184, 185, 187, 189, 190, 192, 193, 195, 196, 198, 199, 201, 202, 204, 205, 206, 208, 209, 210, 212, 213, 214, 216, 217, 218, 219, 221, 222, 223, 224, 225, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 239, 240, 241, 242, 243, 243, 244, 245, 246, 246, 247, 248, 248, 249, 249, 250, 250, 251, 251, 252, 252, 253, 253, 253, 254, 254, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 254, 254, 254, 254, 253, 253, 253, 252, 252, 251, 251, 250, 250, 249, 249, 248, 248, 247, 246, 246, 245, 244, 244, 243, 242, 241, 241, 240, 239, 238, 237, 236, 235, 234, 233, 232, 231, 230, 229, 228, 227, 226, 225, 223, 222, 221, 220, 219, 217, 216, 215, 213, 212, 211, 209, 208, 207, 205, 204, 202, 201, 200, 198, 197, 195, 194, 192, 191, 189, 187, 186, 184, 183, 181, 180, 178, 176, 175, 173, 171, 170, 168, 166, 165, 163, 161, 159, 158, 156, 154, 153, 151, 149, 147, 146, 144, 142, 140, 139, 137, 135, 133, 132, 130, 128, 126, 124, 123, 121, 119, 117, 116, 114, 112, 110, 109, 107, 105, 103, 102, 100, 98, 96, 95, 93, 91, 90, 88, 86, 85, 83, 81, 80, 78, 76, 75, 73, 72, 70, 68, 67, 65, 64, 62, 61, 59, 58, 56, 55, 53, 52, 50, 49, 48, 46, 45, 44, 42, 41, 40, 38, 37, 36, 35, 33, 32, 31, 30, 29, 28, 27, 25, 24, 23, 22, 21, 20, 19, 18, 18, 17, 16, 15, 14, 13, 13, 12, 11, 10, 10, 9, 8, 8, 7, 6, 6, 5, 5, 4, 4, 3, 3, 3, 2, 2, 2, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4, 5, 5, 6, 7, 7, 8, 8, 9, 10, 10, 11, 12, 13, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 34, 35, 36, 37, 39, 40, 41, 42, 44, 45, 47, 48, 49, 51, 52, 54, 55, 56, 58, 59, 61, 62, 64, 66, 67, 69, 70, 72, 73, 75, 77, 78, 80, 82, 83, 85, 87, 88, 90, 92, 93, 95, 97, 98, 100, 102, 104, 105, 107, 109, 111, 112, 114, 116, 118, 119, 121, 123, 125 };
const size_t PS1200[] = { 0, 694, 555, 416, 277, 138 };
const size_t PS2200[] = { 0, 378, 303, 227, 151, 75 };

uint8_t timeskew = 0;

void sendOne(uint32_t *us, uint8_t *phaseShift) {
    uint32_t t;
    while ((t = micros() - *us) < INV_BAUD + (timeskew == 0)) {
      OUT_PORT = (pgm_read_byte(&SINUS1200[ (PS1200[*phaseShift] + t) % N_SINUS_1200 ]) >> 4) | (OUT_PORT & 0xf0);
    }
    *us += INV_BAUD  + (timeskew == 0);
    timeskew = (timeskew + 1) % SKEW_ROUNDS;
}

void sendZero(uint32_t *us, uint8_t *phaseShift) {
    uint32_t t;
    while ((t = micros() - *us) < INV_BAUD + (timeskew == 0)) {
      OUT_PORT = (pgm_read_byte(&SINUS2200[ (PS2200[*phaseShift] + t) % N_SINUS_2200 ]) >> 4) | (OUT_PORT & 0xf0);
    }
    *phaseShift = (*phaseShift + 1) % N_SHIFTS;
    *us += INV_BAUD + (timeskew == 0);
    timeskew = (timeskew + 1) % SKEW_ROUNDS;
}

void setZero() {
  // Setting all to LOW rather than what 0b1000000 (which would be a signal amplitude of 0) saves about 2mA @ R = 550 ohms
  //OUT_PORT = (pgm_read_byte(&SINUS2200[0]) >> 4) | (OUT_PORT & 0xf0);
  OUT_PORT &= 0xf0;
}