Tasmota/lib/lib_display/XPT2046_Touchscreen/XPT2046_Touchscreen.cpp

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/* Touchscreen library for XPT2046 Touch Controller Chip
* Copyright (c) 2015, Paul Stoffregen, paul@pjrc.com
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice, development funding notice, and this permission
* notice shall be included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "XPT2046_Touchscreen.h"
#define Z_THRESHOLD 400
#define Z_THRESHOLD_INT 75
#define MSEC_THRESHOLD 3
#define SPI_SETTING SPISettings(2000000, MSBFIRST, SPI_MODE0)
static XPT2046_Touchscreen *isrPinptr;
void isrPin(void);
bool XPT2046_Touchscreen::begin(SPIClass &wspi)
{
_pspi = &wspi;
_pspi->begin();
pinMode(csPin, OUTPUT);
digitalWrite(csPin, HIGH);
if (255 != tirqPin) {
pinMode( tirqPin, INPUT );
attachInterrupt(digitalPinToInterrupt(tirqPin), isrPin, FALLING);
isrPinptr = this;
}
return true;
}
#if defined(_FLEXIO_SPI_H_)
#define FLEXSPI_SETTING FlexIOSPISettings(2000000, MSBFIRST, SPI_MODE0)
bool XPT2046_Touchscreen::begin(FlexIOSPI &wflexspi)
{
_pspi = nullptr; // make sure we dont use this one...
_pflexspi = &wflexspi;
_pflexspi->begin();
pinMode(csPin, OUTPUT);
digitalWrite(csPin, HIGH);
if (255 != tirqPin) {
pinMode( tirqPin, INPUT );
attachInterrupt(digitalPinToInterrupt(tirqPin), isrPin, FALLING);
isrPinptr = this;
}
return true;
}
#endif
ISR_PREFIX
void isrPin( void )
{
XPT2046_Touchscreen *o = isrPinptr;
o->isrWake = true;
}
TS_Point XPT2046_Touchscreen::getPoint()
{
update();
return TS_Point(xraw, yraw, zraw);
}
bool XPT2046_Touchscreen::tirqTouched()
{
return (isrWake);
}
bool XPT2046_Touchscreen::touched()
{
update();
return (zraw >= Z_THRESHOLD);
}
void XPT2046_Touchscreen::readData(uint16_t *x, uint16_t *y, uint8_t *z)
{
update();
*x = xraw;
*y = yraw;
*z = zraw;
}
bool XPT2046_Touchscreen::bufferEmpty()
{
return ((millis() - msraw) < MSEC_THRESHOLD);
}
static int16_t besttwoavg( int16_t x , int16_t y , int16_t z ) {
int16_t da, db, dc;
int16_t reta = 0;
if ( x > y ) da = x - y; else da = y - x;
if ( x > z ) db = x - z; else db = z - x;
if ( z > y ) dc = z - y; else dc = y - z;
if ( da <= db && da <= dc ) reta = (x + y) >> 1;
else if ( db <= da && db <= dc ) reta = (x + z) >> 1;
else reta = (y + z) >> 1; // else if ( dc <= da && dc <= db ) reta = (x + y) >> 1;
return (reta);
}
// TODO: perhaps a future version should offer an option for more oversampling,
// with the RANSAC algorithm https://en.wikipedia.org/wiki/RANSAC
void XPT2046_Touchscreen::update()
{
int16_t data[6];
int z;
if (!isrWake) return;
uint32_t now = millis();
if (now - msraw < MSEC_THRESHOLD) return;
if (_pspi) {
_pspi->beginTransaction(SPI_SETTING);
digitalWrite(csPin, LOW);
_pspi->transfer(0xB1 /* Z1 */);
int16_t z1 = _pspi->transfer16(0xC1 /* Z2 */) >> 3;
z = z1 + 4095;
int16_t z2 = _pspi->transfer16(0x91 /* X */) >> 3;
z -= z2;
if (z >= Z_THRESHOLD) {
_pspi->transfer16(0x91 /* X */); // dummy X measure, 1st is always noisy
data[0] = _pspi->transfer16(0xD1 /* Y */) >> 3;
data[1] = _pspi->transfer16(0x91 /* X */) >> 3; // make 3 x-y measurements
data[2] = _pspi->transfer16(0xD1 /* Y */) >> 3;
data[3] = _pspi->transfer16(0x91 /* X */) >> 3;
}
else data[0] = data[1] = data[2] = data[3] = 0; // Compiler warns these values may be used unset on early exit.
data[4] = _pspi->transfer16(0xD0 /* Y */) >> 3; // Last Y touch power down
data[5] = _pspi->transfer16(0) >> 3;
digitalWrite(csPin, HIGH);
_pspi->endTransaction();
}
#if defined(_FLEXIO_SPI_H_)
else if (_pflexspi) {
_pflexspi->beginTransaction(FLEXSPI_SETTING);
digitalWrite(csPin, LOW);
_pflexspi->transfer(0xB1 /* Z1 */);
int16_t z1 = _pflexspi->transfer16(0xC1 /* Z2 */) >> 3;
z = z1 + 4095;
int16_t z2 = _pflexspi->transfer16(0x91 /* X */) >> 3;
z -= z2;
if (z >= Z_THRESHOLD) {
_pflexspi->transfer16(0x91 /* X */); // dummy X measure, 1st is always noisy
data[0] = _pflexspi->transfer16(0xD1 /* Y */) >> 3;
data[1] = _pflexspi->transfer16(0x91 /* X */) >> 3; // make 3 x-y measurements
data[2] = _pflexspi->transfer16(0xD1 /* Y */) >> 3;
data[3] = _pflexspi->transfer16(0x91 /* X */) >> 3;
}
else data[0] = data[1] = data[2] = data[3] = 0; // Compiler warns these values may be used unset on early exit.
data[4] = _pflexspi->transfer16(0xD0 /* Y */) >> 3; // Last Y touch power down
data[5] = _pflexspi->transfer16(0) >> 3;
digitalWrite(csPin, HIGH);
_pflexspi->endTransaction();
}
#endif
// If we do not have either _pspi or _pflexspi than bail.
else return;
//Serial.printf("z=%d :: z1=%d, z2=%d ", z, z1, z2);
if (z < 0) z = 0;
if (z < Z_THRESHOLD) { // if ( !touched ) {
// Serial.println();
zraw = 0;
if (z < Z_THRESHOLD_INT) { // if ( !touched ) {
if (255 != tirqPin) isrWake = false;
}
return;
}
zraw = z;
// Average pair with least distance between each measured x then y
//Serial.printf(" z1=%d,z2=%d ", z1, z2);
//Serial.printf("p=%d, %d,%d %d,%d %d,%d", zraw,
//data[0], data[1], data[2], data[3], data[4], data[5]);
int16_t x = besttwoavg( data[0], data[2], data[4] );
int16_t y = besttwoavg( data[1], data[3], data[5] );
//Serial.printf(" %d,%d", x, y);
//Serial.println();
if (z >= Z_THRESHOLD) {
msraw = now; // good read completed, set wait
switch (rotation) {
case 0:
xraw = 4095 - y;
yraw = x;
break;
case 1:
xraw = x;
yraw = y;
break;
case 2:
xraw = y;
yraw = 4095 - x;
break;
default: // 3
xraw = 4095 - x;
yraw = 4095 - y;
}
}
}