350 lines
13 KiB
C++
350 lines
13 KiB
C++
// The following touch screen support code by maxpautsch was merged 1/10/17
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// https://github.com/maxpautsch
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// Define TOUCH_CS is the user setup file to enable this code
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// A demo is provided in examples Generic folder
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// Additions by Bodmer to double sample, use Z value to improve detection reliability
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// and to correct rotation handling
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// See license in root directory.
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// Define a default pressure threshold
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#ifndef Z_THRESHOLD
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#define Z_THRESHOLD 350 // Touch pressure threshold for validating touches
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#endif
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/***************************************************************************************
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** Function name: begin_touch_read_write - was spi_begin_touch
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** Description: Start transaction and select touch controller
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***************************************************************************************/
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// The touch controller has a low SPI clock rate
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inline void TFT_eSPI::begin_touch_read_write(void){
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DMA_BUSY_CHECK;
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CS_H; // Just in case it has been left low
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#if defined (SPI_HAS_TRANSACTION) && defined (SUPPORT_TRANSACTIONS)
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if (locked) {locked = false; spi.beginTransaction(SPISettings(SPI_TOUCH_FREQUENCY, MSBFIRST, SPI_MODE0));}
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#else
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spi.setFrequency(SPI_TOUCH_FREQUENCY);
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#endif
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SET_BUS_READ_MODE;
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T_CS_L;
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}
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/***************************************************************************************
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** Function name: end_touch_read_write - was spi_end_touch
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** Description: End transaction and deselect touch controller
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***************************************************************************************/
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inline void TFT_eSPI::end_touch_read_write(void){
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T_CS_H;
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#if defined (SPI_HAS_TRANSACTION) && defined (SUPPORT_TRANSACTIONS)
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if(!inTransaction) {if (!locked) {locked = true; spi.endTransaction();}}
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#else
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spi.setFrequency(SPI_FREQUENCY);
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#endif
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//SET_BUS_WRITE_MODE;
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}
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/***************************************************************************************
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** Function name: Legacy - deprecated
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** Description: Start/end transaction
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***************************************************************************************/
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void TFT_eSPI::spi_begin_touch() {begin_touch_read_write();}
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void TFT_eSPI::spi_end_touch() { end_touch_read_write();}
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/***************************************************************************************
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** Function name: getTouchRaw
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** Description: read raw touch position. Always returns true.
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***************************************************************************************/
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uint8_t TFT_eSPI::getTouchRaw(uint16_t *x, uint16_t *y){
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uint16_t tmp;
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begin_touch_read_write();
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// Start YP sample request for x position, read 4 times and keep last sample
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spi.transfer(0xd0); // Start new YP conversion
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spi.transfer(0); // Read first 8 bits
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spi.transfer(0xd0); // Read last 8 bits and start new YP conversion
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spi.transfer(0); // Read first 8 bits
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spi.transfer(0xd0); // Read last 8 bits and start new YP conversion
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spi.transfer(0); // Read first 8 bits
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spi.transfer(0xd0); // Read last 8 bits and start new YP conversion
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tmp = spi.transfer(0); // Read first 8 bits
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tmp = tmp <<5;
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tmp |= 0x1f & (spi.transfer(0x90)>>3); // Read last 8 bits and start new XP conversion
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*x = tmp;
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// Start XP sample request for y position, read 4 times and keep last sample
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spi.transfer(0); // Read first 8 bits
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spi.transfer(0x90); // Read last 8 bits and start new XP conversion
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spi.transfer(0); // Read first 8 bits
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spi.transfer(0x90); // Read last 8 bits and start new XP conversion
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spi.transfer(0); // Read first 8 bits
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spi.transfer(0x90); // Read last 8 bits and start new XP conversion
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tmp = spi.transfer(0); // Read first 8 bits
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tmp = tmp <<5;
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tmp |= 0x1f & (spi.transfer(0)>>3); // Read last 8 bits
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*y = tmp;
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end_touch_read_write();
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return true;
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}
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/***************************************************************************************
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** Function name: getTouchRawZ
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** Description: read raw pressure on touchpad and return Z value.
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***************************************************************************************/
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uint16_t TFT_eSPI::getTouchRawZ(void){
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begin_touch_read_write();
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// Z sample request
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int16_t tz = 0xFFF;
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spi.transfer(0xb0); // Start new Z1 conversion
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tz += spi.transfer16(0xc0) >> 3; // Read Z1 and start Z2 conversion
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tz -= spi.transfer16(0x00) >> 3; // Read Z2
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end_touch_read_write();
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if (tz == 4095) tz = 0;
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return (uint16_t)tz;
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}
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/***************************************************************************************
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** Function name: validTouch
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** Description: read validated position. Return false if not pressed.
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***************************************************************************************/
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#define _RAWERR 20 // Deadband error allowed in successive position samples
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uint8_t TFT_eSPI::validTouch(uint16_t *x, uint16_t *y, uint16_t threshold){
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uint16_t x_tmp, y_tmp, x_tmp2, y_tmp2;
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// Wait until pressure stops increasing to debounce pressure
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uint16_t z1 = 1;
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uint16_t z2 = 0;
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while (z1 > z2)
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{
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z2 = z1;
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z1 = getTouchRawZ();
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delay(1);
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}
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// Serial.print("Z = ");Serial.println(z1);
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if (z1 <= threshold) return false;
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getTouchRaw(&x_tmp,&y_tmp);
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// Serial.print("Sample 1 x,y = "); Serial.print(x_tmp);Serial.print(",");Serial.print(y_tmp);
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// Serial.print(", Z = ");Serial.println(z1);
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delay(1); // Small delay to the next sample
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if (getTouchRawZ() <= threshold) return false;
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delay(2); // Small delay to the next sample
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getTouchRaw(&x_tmp2,&y_tmp2);
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// Serial.print("Sample 2 x,y = "); Serial.print(x_tmp2);Serial.print(",");Serial.println(y_tmp2);
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// Serial.print("Sample difference = ");Serial.print(abs(x_tmp - x_tmp2));Serial.print(",");Serial.println(abs(y_tmp - y_tmp2));
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if (abs(x_tmp - x_tmp2) > _RAWERR) return false;
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if (abs(y_tmp - y_tmp2) > _RAWERR) return false;
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*x = x_tmp;
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*y = y_tmp;
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return true;
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}
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/***************************************************************************************
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** Function name: getTouch
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** Description: read callibrated position. Return false if not pressed.
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***************************************************************************************/
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uint8_t TFT_eSPI::getTouch(uint16_t *x, uint16_t *y, uint16_t threshold){
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uint16_t x_tmp, y_tmp;
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if (threshold<20) threshold = 20;
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if (_pressTime > millis()) threshold=20;
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uint8_t n = 5;
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uint8_t valid = 0;
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while (n--)
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{
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if (validTouch(&x_tmp, &y_tmp, threshold)) valid++;;
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}
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if (valid<1) { _pressTime = 0; return false; }
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_pressTime = millis() + 50;
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convertRawXY(&x_tmp, &y_tmp);
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if (x_tmp >= _width || y_tmp >= _height) return false;
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_pressX = x_tmp;
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_pressY = y_tmp;
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*x = _pressX;
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*y = _pressY;
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return valid;
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}
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/***************************************************************************************
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** Function name: convertRawXY
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** Description: convert raw touch x,y values to screen coordinates
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***************************************************************************************/
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void TFT_eSPI::convertRawXY(uint16_t *x, uint16_t *y)
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{
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uint16_t x_tmp = *x, y_tmp = *y, xx, yy;
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if(!touchCalibration_rotate){
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xx=(x_tmp-touchCalibration_x0)*_width/touchCalibration_x1;
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yy=(y_tmp-touchCalibration_y0)*_height/touchCalibration_y1;
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if(touchCalibration_invert_x)
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xx = _width - xx;
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if(touchCalibration_invert_y)
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yy = _height - yy;
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} else {
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xx=(y_tmp-touchCalibration_x0)*_width/touchCalibration_x1;
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yy=(x_tmp-touchCalibration_y0)*_height/touchCalibration_y1;
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if(touchCalibration_invert_x)
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xx = _width - xx;
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if(touchCalibration_invert_y)
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yy = _height - yy;
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}
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*x = xx;
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*y = yy;
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}
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/***************************************************************************************
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** Function name: calibrateTouch
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** Description: generates calibration parameters for touchscreen.
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***************************************************************************************/
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void TFT_eSPI::calibrateTouch(uint16_t *parameters, uint32_t color_fg, uint32_t color_bg, uint8_t size){
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int16_t values[] = {0,0,0,0,0,0,0,0};
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uint16_t x_tmp, y_tmp;
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for(uint8_t i = 0; i<4; i++){
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fillRect(0, 0, size+1, size+1, color_bg);
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fillRect(0, _height-size-1, size+1, size+1, color_bg);
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fillRect(_width-size-1, 0, size+1, size+1, color_bg);
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fillRect(_width-size-1, _height-size-1, size+1, size+1, color_bg);
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if (i == 5) break; // used to clear the arrows
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switch (i) {
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case 0: // up left
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drawLine(0, 0, 0, size, color_fg);
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drawLine(0, 0, size, 0, color_fg);
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drawLine(0, 0, size , size, color_fg);
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break;
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case 1: // bot left
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drawLine(0, _height-size-1, 0, _height-1, color_fg);
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drawLine(0, _height-1, size, _height-1, color_fg);
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drawLine(size, _height-size-1, 0, _height-1 , color_fg);
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break;
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case 2: // up right
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drawLine(_width-size-1, 0, _width-1, 0, color_fg);
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drawLine(_width-size-1, size, _width-1, 0, color_fg);
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drawLine(_width-1, size, _width-1, 0, color_fg);
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break;
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case 3: // bot right
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drawLine(_width-size-1, _height-size-1, _width-1, _height-1, color_fg);
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drawLine(_width-1, _height-1-size, _width-1, _height-1, color_fg);
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drawLine(_width-1-size, _height-1, _width-1, _height-1, color_fg);
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break;
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}
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// user has to get the chance to release
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if(i>0) delay(1000);
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for(uint8_t j= 0; j<8; j++){
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// Use a lower detect threshold as corners tend to be less sensitive
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while(!validTouch(&x_tmp, &y_tmp, Z_THRESHOLD/2));
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values[i*2 ] += x_tmp;
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values[i*2+1] += y_tmp;
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}
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values[i*2 ] /= 8;
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values[i*2+1] /= 8;
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}
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// from case 0 to case 1, the y value changed.
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// If the measured delta of the touch x axis is bigger than the delta of the y axis, the touch and TFT axes are switched.
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touchCalibration_rotate = false;
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if(abs(values[0]-values[2]) > abs(values[1]-values[3])){
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touchCalibration_rotate = true;
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touchCalibration_x0 = (values[1] + values[3])/2; // calc min x
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touchCalibration_x1 = (values[5] + values[7])/2; // calc max x
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touchCalibration_y0 = (values[0] + values[4])/2; // calc min y
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touchCalibration_y1 = (values[2] + values[6])/2; // calc max y
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} else {
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touchCalibration_x0 = (values[0] + values[2])/2; // calc min x
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touchCalibration_x1 = (values[4] + values[6])/2; // calc max x
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touchCalibration_y0 = (values[1] + values[5])/2; // calc min y
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touchCalibration_y1 = (values[3] + values[7])/2; // calc max y
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}
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// in addition, the touch screen axis could be in the opposite direction of the TFT axis
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touchCalibration_invert_x = false;
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if(touchCalibration_x0 > touchCalibration_x1){
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values[0]=touchCalibration_x0;
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touchCalibration_x0 = touchCalibration_x1;
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touchCalibration_x1 = values[0];
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touchCalibration_invert_x = true;
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}
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touchCalibration_invert_y = false;
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if(touchCalibration_y0 > touchCalibration_y1){
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values[0]=touchCalibration_y0;
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touchCalibration_y0 = touchCalibration_y1;
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touchCalibration_y1 = values[0];
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touchCalibration_invert_y = true;
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}
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// pre calculate
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touchCalibration_x1 -= touchCalibration_x0;
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touchCalibration_y1 -= touchCalibration_y0;
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if(touchCalibration_x0 == 0) touchCalibration_x0 = 1;
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if(touchCalibration_x1 == 0) touchCalibration_x1 = 1;
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if(touchCalibration_y0 == 0) touchCalibration_y0 = 1;
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if(touchCalibration_y1 == 0) touchCalibration_y1 = 1;
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// export parameters, if pointer valid
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if(parameters != NULL){
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parameters[0] = touchCalibration_x0;
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parameters[1] = touchCalibration_x1;
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parameters[2] = touchCalibration_y0;
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parameters[3] = touchCalibration_y1;
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parameters[4] = touchCalibration_rotate | (touchCalibration_invert_x <<1) | (touchCalibration_invert_y <<2);
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}
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}
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/***************************************************************************************
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** Function name: setTouch
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** Description: imports calibration parameters for touchscreen.
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***************************************************************************************/
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void TFT_eSPI::setTouch(uint16_t *parameters){
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touchCalibration_x0 = parameters[0];
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touchCalibration_x1 = parameters[1];
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touchCalibration_y0 = parameters[2];
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touchCalibration_y1 = parameters[3];
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if(touchCalibration_x0 == 0) touchCalibration_x0 = 1;
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if(touchCalibration_x1 == 0) touchCalibration_x1 = 1;
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if(touchCalibration_y0 == 0) touchCalibration_y0 = 1;
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if(touchCalibration_y1 == 0) touchCalibration_y1 = 1;
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touchCalibration_rotate = parameters[4] & 0x01;
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touchCalibration_invert_x = parameters[4] & 0x02;
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touchCalibration_invert_y = parameters[4] & 0x04;
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}
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