pcmhacking.net

Code: Select all

    // --- Calculate RPM timing (µs per event) ---
    unsigned long RPMTime = pulseHighTime + pulseLowTime;
    RPMTime = constrain(RPMTime, 134, 125000);  // 18600 RPM to 20 RPM
    IndexFull = (2500000/(RPMTime*600));
    IndexWhole = (int)IndexFull;
    IndexPlusOne = IndexWhole + 1;
    IndexPlusOne = constrain(IndexPlusOne, 0, 31);
    TerpA = Iend[9][adcIndex];//
    TerpB = Iend[10][adcIndex];//
    Diff = TerpB - TerpA;
    Frac = .5; //IndexFull - IndexWhole;
    TerpC = Diff * Frac;
    TerpD = TerpA + TerpC;

Code: Select all

    unsigned long RPMTime = pulseHighTime + pulseLowTime;
    RPMTime = constrain(RPMTime, 134, 125000);  // 18600 RPM to 20 RPM
    IndexFull = (2500000/(RPMTime*600));
    IndexWhole = (int)IndexFull;
    //IndexPlusOne = IndexWhole + 1;
    //IndexPlusOne = constrain(IndexPlusOne, 0, 31);
    //TerpA = Iend[IndexWhole][adcIndex];//
    //TerpB = Iend[IndexPlusOne][adcIndex];//
    //Diff = TerpB - TerpA;
    //Frac = .5; //IndexFull - IndexWhole;
    //TerpC = Diff * Frac;
    //TerpD = TerpA + TerpC;



    // --- Update delay values from tables ---
    currentOnDelay11 = Dstart[IndexWhole][adcIndex];
    currentOffDelay11 = Dend[IndexWhole][adcIndex];

    currentOnDelay4 = Istart[IndexWhole][adcIndex];
    currentOnDelay4 = Iend[IndexWhole][adcIndex];
    //currentOffDelay4 = TerpD;

Code: Select all

    IndexFull = (2500000/(RPMTime*600));
    IndexWhole = (int)IndexFull;

Code: Select all

    IndexWhole = (int)(2500000/(RPMTime*600));

Code: Select all

unsigned long RPMTime = pulseHighTime + pulseLowTime;
RPMTime = constrain(RPMTime, 134, 125000);  // Clamp RPMTime for your RPM range

// Calculate IndexFull in fixed-point 16.16 format
uint32_t IndexFull_fixed = (uint32_t)((2500000ULL << 16) / (RPMTime * 600UL));  // <<16 for fractional bits
uint16_t Frac_fixed = IndexFull_fixed & 0xFFFF;      // Fractional part (0 to 65535)
uint8_t IndexWhole = (IndexFull_fixed >> 16);        // Whole part

IndexWhole = constrain(IndexWhole, 0, 31);
uint8_t IndexPlusOne = constrain(IndexWhole + 1, 0, 31);

// Get lookup values from your table
uint16_t TerpA = Iend[IndexWhole][adcIndex];
uint16_t TerpB = Iend[IndexPlusOne][adcIndex];

// Integer linear interpolation: TerpD = TerpA + ( (TerpB - TerpA) * Frac_fixed ) >> 16;
int16_t Diff = (int16_t)TerpB - (int16_t)TerpA;
uint16_t TerpD = TerpA + ((int32_t)Diff * Frac_fixed >> 16);

// TerpD is your interpolated result, integer, .00 precision (whole number)