MCUFRIEND_kbv/examples/TouchScreen_Calibr_native/TouchScreen_kbv.cpp

// Touch screen library with X Y and Z (pressure) readings as well
// as oversampling to avoid 'bouncing'
// adapted from (c) ladyada / adafruit

#include "Arduino.h"

#include "TouchScreen_kbv.h"

#define NUMSAMPLES 3  //.kbv
#if defined(__STM32F1__) || defined(ESP32)   //Maple core
#define ADC_ADJUST >>2
#else
#define ADC_ADJUST
#endif

TSPoint_kbv::TSPoint_kbv(void) {
    x = y = 0;
}

TSPoint_kbv::TSPoint_kbv(int16_t x0, int16_t y0, int16_t z0) {
    x = x0;
    y = y0;
    z = z0;
}

bool TSPoint_kbv::operator==(TSPoint_kbv p1) {
    return  ((p1.x == x) && (p1.y == y) && (p1.z == z));
}

bool TSPoint_kbv::operator!=(TSPoint_kbv p1) {
    return  ((p1.x != x) || (p1.y != y) || (p1.z != z));
}

static void insert_sort(int array[], uint8_t size) {
    uint8_t j;
    int save;

    for (int i = 1; i < size; i++) {
        save = array[i];
        for (j = i; j >= 1 && save < array[j - 1]; j--)
            array[j] = array[j - 1];
        array[j] = save;
    }
}

TSPoint_kbv TouchScreen_kbv::getPoint(void) {
    int x, y, z;
    int samples[NUMSAMPLES];
    uint8_t i, valid;

    valid = 1;

    pinMode(_yp, INPUT);
    pinMode(_ym, INPUT);

    digitalWrite(_yp, LOW);
    digitalWrite(_ym, LOW);

    pinMode(_xp, OUTPUT);
    pinMode(_xm, OUTPUT);
    digitalWrite(_xp, HIGH);
    digitalWrite(_xm, LOW);

    for (i = 0; i < NUMSAMPLES; i++) {
        samples[i] = analogRead(_yp) ADC_ADJUST;
    }
    insert_sort(samples, NUMSAMPLES);
    x = (1023 - samples[NUMSAMPLES / 2]); //choose median

    pinMode(_xp, INPUT);
    pinMode(_xm, INPUT);
    digitalWrite(_xp, LOW);
    digitalWrite(_xm, LOW);     //.kbv for Due

    pinMode(_yp, OUTPUT);
    digitalWrite(_yp, HIGH);
    pinMode(_ym, OUTPUT);
    digitalWrite(_ym, LOW);     //.kbv for Due

    for (i = 0; i < NUMSAMPLES; i++) {
        samples[i] = analogRead(_xm) ADC_ADJUST;
    }

    insert_sort(samples, NUMSAMPLES);

    y = (1023 - samples[NUMSAMPLES / 2]);

    // Set X+ to ground
    pinMode(_xp, OUTPUT);
    digitalWrite(_xp, LOW);

    // Set Y- to VCC
    pinMode(_ym, OUTPUT);     //.kbv
    digitalWrite(_ym, HIGH);

    // Hi-Z X- and Y+
    digitalWrite(_xm, LOW);   //.kbv
    pinMode(_xm, INPUT);      //.kbv
    digitalWrite(_yp, LOW);
    pinMode(_yp, INPUT);

    int z1 = analogRead(_xm) ADC_ADJUST;
    int z2 = analogRead(_yp) ADC_ADJUST;

    z = (1023 - (z2 - z1));

    return TSPoint_kbv(x, y, z);  //XM, YP still in ANALOG mode
}

TouchScreen_kbv::TouchScreen_kbv(uint8_t xp, uint8_t yp, uint8_t xm, uint8_t ym) {
    _yp = yp;
    _xm = xm;
    _ym = ym;
    _xp = xp;
    _rxplate = 0;
    pressureThreshhold = 10;
}


TouchScreen_kbv::TouchScreen_kbv(uint8_t xp, uint8_t yp, uint8_t xm, uint8_t ym,
                         uint16_t rxplate) {
    _yp = yp;
    _xm = xm;
    _ym = ym;
    _xp = xp;
    _rxplate = rxplate;

    pressureThreshhold = 10;
}

int TouchScreen_kbv::readTouchX(void) {
    pinMode(_yp, INPUT);
    pinMode(_ym, INPUT);
    digitalWrite(_yp, LOW);
    digitalWrite(_ym, LOW);

    pinMode(_xp, OUTPUT);
    digitalWrite(_xp, HIGH);
    pinMode(_xm, OUTPUT);
    digitalWrite(_xm, LOW);

    return (1023 - (analogRead(_yp)) ADC_ADJUST);
}


int TouchScreen_kbv::readTouchY(void) {
    pinMode(_xp, INPUT);
    pinMode(_xm, INPUT);
    digitalWrite(_xp, LOW);
    digitalWrite(_xm, LOW);

    pinMode(_yp, OUTPUT);
    digitalWrite(_yp, HIGH);
    pinMode(_ym, OUTPUT);
    digitalWrite(_ym, LOW);

    return (1023 - (analogRead(_xm)) ADC_ADJUST);
}


uint16_t TouchScreen_kbv::pressure(void) {
    // Set X+ to ground
    pinMode(_xp, OUTPUT);
    digitalWrite(_xp, LOW);

    // Set Y- to VCC
    pinMode(_ym, OUTPUT);
    digitalWrite(_ym, HIGH);

    // Hi-Z X- and Y+
    digitalWrite(_xm, LOW);
    pinMode(_xm, INPUT);
    digitalWrite(_yp, LOW);
    pinMode(_yp, INPUT);

    int z1 = analogRead(_xm) ADC_ADJUST;
    int z2 = analogRead(_yp) ADC_ADJUST;

    return (1023 - (z2 - z1));
}