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Update touch handler

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Added new function that sketch can call to convert raw ADC x and y
values to calibrated screen coordinates:
tft.convertRawXY(&x, &y);

Redunced required number of SPI transfers needed to read raw values.
Changed mode so PENIRQ pin is enabled so users sketch can read this
signal (if needed).

See issue #279.
This commit is contained in:
Bodmer
2019-01-01 23:56:08 +00:00
parent 71a222f704
commit e8c201db5e
4 changed files with 52 additions and 36 deletions
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Extensions/Touch.cpp
+36 -29
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@@ -22,24 +22,18 @@ uint8_t TFT_eSPI::getTouchRaw(uint16_t *x, uint16_t *y){
T_CS_L;
// Dummy transfer
SPI.transfer(0xd0);
SPI.transfer(0);
SPI.transfer(0);
// Start bit + YP sample request for x position
SPI.transfer(0xd0);
tmp = SPI.transfer(0);
// Start YP sample request for x position
SPI.transfer(0xd0); // Start new YP conversion
tmp = SPI.transfer(0); // Read first 8 bits
tmp = tmp <<5;
tmp |= 0x1f & (SPI.transfer(0)>>3);
tmp |= 0x1f & (SPI.transfer(0x90)>>3); // Read last 8 bits and start new XP conversion
*x = tmp;
// Start bit + XP sample request for y position
SPI.transfer(0x90);
tmp = SPI.transfer(0);
// Start XP sample request for y position
tmp = SPI.transfer(0); // Read first 8 bits
tmp = tmp <<5;
tmp |= 0x1f & (SPI.transfer(0)>>3);
tmp |= 0x1f & (SPI.transfer(0)>>3); // Read last 8 bits
*y = tmp;
@@ -61,12 +55,12 @@ uint16_t TFT_eSPI::getTouchRawZ(void){
T_CS_L;
// Z sample request
// Calculate Z
int16_t tz = 0xFFF;
SPI.transfer(0xb1);
tz += SPI.transfer16(0xc1) >> 3;
tz -= SPI.transfer16(0x91) >> 3;
SPI.transfer(0xb0); // Start new Z1 conversion
tz += SPI.transfer16(0xc0) >> 3; // Read Z1 and start Z2 conversion
tz -= SPI.transfer16(0x00) >> 3; // Read Z2
T_CS_H;
spi_end_touch();
@@ -78,11 +72,11 @@ uint16_t TFT_eSPI::getTouchRawZ(void){
** Function name: validTouch
** Description: read validated position. Return false if not pressed.
***************************************************************************************/
#define _RAWERR 10 // Deadband in position samples
#define _RAWERR 10 // Deadband error allowed in successive position samples
uint8_t TFT_eSPI::validTouch(uint16_t *x, uint16_t *y, uint16_t threshold){
uint16_t x_tmp, y_tmp, x_tmp2, y_tmp2;
// Wait until pressure stops increasing
// Wait until pressure stops increasing to debounce pressure
uint16_t z1 = 1;
uint16_t z2 = 0;
while (z1 > z2)
@@ -125,7 +119,7 @@ uint8_t TFT_eSPI::validTouch(uint16_t *x, uint16_t *y, uint16_t threshold){
***************************************************************************************/
#define Z_THRESHOLD 350 // Touch pressure threshold for validating touches
uint8_t TFT_eSPI::getTouch(uint16_t *x, uint16_t *y, uint16_t threshold){
uint16_t x_tmp, y_tmp, xx, yy;
uint16_t x_tmp, y_tmp;
if (threshold<20) threshold = 20;
if (_pressTime > millis()) threshold=20;
@@ -141,6 +135,25 @@ uint8_t TFT_eSPI::getTouch(uint16_t *x, uint16_t *y, uint16_t threshold){
_pressTime = millis() + 50;
convertRawXY(&x_tmp, &y_tmp);
if (x_tmp >= _width || y_tmp >= _height) return valid;
_pressX = x_tmp;
_pressY = y_tmp;
*x = _pressX;
*y = _pressY;
return valid;
}
/***************************************************************************************
** Function name: convertRawXY
** Description: convert raw touch x,y values to screen coordinates
***************************************************************************************/
void TFT_eSPI::convertRawXY(uint16_t *x, uint16_t *y)
{
uint16_t x_tmp = *x, y_tmp = *y, xx, yy;
if(!touchCalibration_rotate){
xx=(x_tmp-touchCalibration_x0)*_width/touchCalibration_x1;
yy=(y_tmp-touchCalibration_y0)*_height/touchCalibration_y1;
@@ -156,14 +169,8 @@ uint8_t TFT_eSPI::getTouch(uint16_t *x, uint16_t *y, uint16_t threshold){
if(touchCalibration_invert_y)
yy = _height - yy;
}
if (xx >= _width || yy >= _height) return valid;
_pressX = xx;
_pressY = yy;
*x = _pressX;
*y = _pressY;
return valid;
*x = xx;
*y = yy;
}
/***************************************************************************************