/**
* Interrupt handler for the TouchScreen.
* Handles pen press, pen move and pen release events
* by invoking three callback functions.
*/
void TSD_Handler(uint32_t dwAdcStatus)
{
Adc *pAdc = ADC;
uint32_t status;
/* TSADC status */
status = dwAdcStatus;
status &= /*ADC_GetItMask(pAdc) &*/ TS_STATUSES;
if (status == 0) return;
/* Pen released */
if (status & ADC_ISR_NOPEN)
{
if ((bTsFlags & TS_PEN_STAT) == 0)
{
/* Register last data */
memcpy(dwLastTsData, dwTsData, sizeof(dwTsData));
/* Invoke PenReleased callback */
if (TSDCom_IsCalibrationOk())
TSD_PenReleased(dwTsData[0], dwTsData[1]);
}
bTsFlags = 0;
/* Stop periodic trigger & enable pen */
ADC_SetTsAverage(pAdc, ADC_TSMR_TSAV_NO_FILTER);
ADC_SetTsDebounce(pAdc, BOARD_TOUCHSCREEN_DEBOUNCE);
ADC_SetTriggerMode(pAdc, ADC_TRGR_TRGMOD_PEN_TRIG);
/* Disable pen release detect */
ADC_DisableIt(pAdc, ADC_IDR_NOPEN);
/* Enable pen press detect */
ADC_EnableIt(pAdc, ADC_IER_PEN);
}
/* Pen pressed */
else if (status & ADC_ISR_PEN)
{
bTsFlags |= TS_PEN_STAT;
/* Configure for peripdic trigger */
ADC_SetTsAverage(pAdc, ADC_TSMR_TSAV_AVG8CONV);
ADC_SetTsDebounce(pAdc, 300); /* 300ns */
ADC_SetTriggerMode(pAdc, ADC_TRGR_TRGMOD_PERIOD_TRIG);
/* Disable pen press detect */
ADC_DisableIt(pAdc, ADC_IDR_PEN);
/* Enable pen release detect */
ADC_EnableIt(pAdc, ADC_IER_NOPEN|ADC_IER_XRDY|ADC_IER_YRDY|ADC_IER_PRDY);
}
else if (status & ADC_ISR_PENS)
{
/* X */
if (status & ADC_ISR_XRDY)
{
bTsFlags |= TS_X_RDY;
}
/* Y */
if (status & ADC_ISR_YRDY)
{
bTsFlags |= TS_Y_RDY;
}
/* P: (X/1024)*[(Z2/Z1)-1] */
if (status & ADC_ISR_PRDY)
{
bTsFlags |= TS_P_RDY;
}
}
/* X,Y,P are ready */
if ((bTsFlags & TS_DATA_RDY) == TS_DATA_RDY)
{
uint32_t xpos, z2, z1;
bTsFlags &= ~TS_DATA_RDY;
/* Get X,Y */
TSD_GetRawMeasurement(dwRaw);
/* Interprate X,Y */
TSDCom_InterpolateMeasurement(dwRaw, dwTsData);
/* Get P: Rp = Rxp*(Xpos/1024)*[(Z2/Z1)-1] */
dwRaw[2] = ADC_GetTsPressure(pAdc);
#ifdef TS_XY_SWAP
xpos = (dwRaw[1]);
#else
xpos = (dwRaw[0]);
#endif
xpos = (xpos & ADC_XPOSR_XPOS_Msk) >> ADC_XPOSR_XPOS_Pos;
z2 = (dwRaw[2] & ADC_PRESSR_Z2_Msk) >> ADC_PRESSR_Z2_Pos;
z1 = (dwRaw[2] & ADC_PRESSR_Z1_Msk) >> ADC_PRESSR_Z1_Pos;
dwTsData[2] = (xpos) * (z2 - z1) / z1;
/* PenPress */
if (bTsFlags & TS_PEN_STAT)
{
bTsFlags &= ~TS_PEN_STAT;
/* Invoke PenPress callback */
if (TSDCom_IsCalibrationOk())
TSD_PenPressed(dwTsData[0], dwTsData[1], dwTsData[2]);
}
/* Periodic if data change invoke callback */
if (dwTsData[0] != dwLastTsData[0]
|| dwTsData[1] != dwLastTsData[1]
|| dwTsData[2] != dwLastTsData[2] )
{
/* Register last data */
memcpy(dwLastTsData, dwTsData, sizeof(dwTsData));
/* Invoke PenMoved callback */
if (TSDCom_IsCalibrationOk())
TSD_PenMoved(dwTsData[0], dwTsData[1], dwTsData[2]);
}
}
//------------------------------------------------------------------------------
/// Interrupt handler for the TSADC. Handles pen press, pen move and pen release
/// events by invoking three callback functions.
//------------------------------------------------------------------------------
static void InterruptHandler(void)
{
unsigned int status;
unsigned int data[2];
static unsigned int newPoint[2];
static unsigned int point[2];
static unsigned char report = 0;
// Retrieve TADC status
// Bug fix: two step operation so IAR doesn't complain that the order of
// volatile access is unspecified.
status = AT91C_BASE_TSADC->TSADC_SR;
status &= AT91C_BASE_TSADC->TSADC_IMR;
// Pen release
if ((status & AT91C_TSADC_NOCNT) == AT91C_TSADC_NOCNT) {
// Invoke PenReleased callback
if(TSDCom_IsCalibrationOk()) {
TSD_PenReleased(point[0], point[1]);
}
// Stop periodic trigger mode
TSADCC_SetDebounceTime(BOARD_TOUCHSCREEN_DEBOUNCE);
AT91C_BASE_TSADC->TSADC_IDR = AT91C_TSADC_EOC3 | AT91C_TSADC_NOCNT;
TSADCC_SetTriggerMode(AT91C_TSADC_TRGMOD_PENDET_TRIGGER);
TSD_GetRawMeasurement(data); // Clear data registers
AT91C_BASE_TSADC->TSADC_SR;
AT91C_BASE_TSADC->TSADC_IER = AT91C_TSADC_PENCNT;
}
// Pen press
else if ((status & AT91C_TSADC_PENCNT) == AT91C_TSADC_PENCNT) {
// Invoke PenPressed callback with (x,y) coordinates
while ((AT91C_BASE_TSADC->TSADC_SR & AT91C_TSADC_EOC3) != AT91C_TSADC_EOC3);
TSD_GetRawMeasurement(data);
TSDCom_InterpolateMeasurement(data, point);
// Invoke PenPressed callback
if(TSDCom_IsCalibrationOk()) {
TSD_PenPressed(point[0], point[1]);
}
// Configure TSADC for periodic trigger
TSADCC_SetDebounceTime(10); // 1ns
AT91C_BASE_TSADC->TSADC_IER = AT91C_TSADC_EOC3 | AT91C_TSADC_NOCNT;
AT91C_BASE_TSADC->TSADC_IDR = AT91C_TSADC_PENCNT;
TSADCC_SetTriggerPeriod(10000000); // 10ms
TSADCC_SetTriggerMode(AT91C_TSADC_TRGMOD_PERIODIC_TRIGGER);
report = 0;
}
// Pen move
else if ((status & AT91C_TSADC_EOC3) == AT91C_TSADC_EOC3) {
// Invoke callback with LAST value measured
// Explanation: the very last value that will be measured (just as the
// pen is released) might be corrupted and there is no way to know. So
// we just discard it.
if (report) {
memcpy(point, newPoint, sizeof(newPoint));
// Invoke PenMoved callback
if(TSDCom_IsCalibrationOk()) {
TSD_PenMoved(point[0], point[1]);
}
report = 0;
}
TSD_GetRawMeasurement(data);
TSDCom_InterpolateMeasurement(data, newPoint);
if ((newPoint[0] != point[0]) || (newPoint[1] != point[1])) {
report = 1;
}
}
}
/**
* \brief Performs the calibration process using the provided buffer to display
* information.
*
* \return True if calibration was successful; otherwise false.
*/
uint8_t TSDCom_Calibrate(void)
{
volatile uint32_t i; /* to keep the tempo with gcc code optimisation */
int32_t slope1, slope2;
CalibrationPoint measuredPoint;
uint8_t xOk, yOk;
int32_t xDiff, yDiff;
/* Calibration setup */
LCDD_Fill(COLOR_WHITE);
LCDD_DrawString(30, 50, (uint8_t *)"LCD calibration", COLOR_BLACK);
LCDD_DrawString(1, 140, (uint8_t *)"Touch the dots to\ncalibrate the screen", COLOR_DARKBLUE);
/* Calibration points */
for (i=0; i < 4; i++) {
DrawCalibrationPoint(&calibrationPoints[i]);
/* Wait for touch & end of conversion */
TSD_WaitPenPressed();
TSD_GetRawMeasurement(calibrationPoints[i].data);
ClearCalibrationPoint(&calibrationPoints[i]);
/* Wait for contact loss */
TSD_WaitPenReleased();
}
/**
* Calculate slopes using the calibration data
* Theory behind those calculations:
* - We suppose the touchscreen measurements are linear, so the following equations are true (simple
* linear regression) for any two 'a' and 'b' points of the screen:
* dx = (a.data[0] - b.data[0]) / (a.x - b.x)
* dy = (a.data[1] - b.data[1]) / (a.y - b.y)
*
* - We calculate dx and dy (called xslope and yslope here) using the calibration points.
*
* - We can then use dx and dy to infer the position of a point 'p' given the measurements performed
* by the touchscreen ('c' is any of the calibration points):
* dx = (p.data[0] - c.data[0]) / (p.x - c.x)
* dy = (p.data[1] - c.data[1]) / (p.y - c.y)
* Thus:
* p.x = c.x - (p.data[0] - c.data[0]) / dx
* p.y = c.y - (p.data[1] - c.data[1]) / dy
*
* - Since there are four calibration points, dx and dy can be calculated twice, so we average
* the two values.
*/
slope1 = ((int32_t) calibrationPoints[0].data[0]) - ((int32_t) calibrationPoints[1].data[0]);
slope1 *= 1024;
slope1 /= ((int32_t) calibrationPoints[0].x) - ((int32_t) calibrationPoints[1].x);
slope2 = ((int32_t) calibrationPoints[2].data[0]) - ((int32_t) calibrationPoints[3].data[0]);
slope2 *= 1024;
slope2 /= ((int32_t) calibrationPoints[2].x) - ((int32_t) calibrationPoints[3].x);
xSlope = (slope1 + slope2) / 2;
slope1 = ((int32_t) calibrationPoints[0].data[1]) - ((int32_t) calibrationPoints[2].data[1]);
slope1 *= 1024;
slope1 /= ((int32_t) calibrationPoints[0].y) - ((int32_t) calibrationPoints[2].y);
slope2 = ((int32_t) calibrationPoints[1].data[1]) - ((int32_t) calibrationPoints[3].data[1]);
slope2 *= 1024;
slope2 /= ((int32_t) calibrationPoints[1].y) - ((int32_t) calibrationPoints[3].y);
ySlope = (slope1 + slope2) / 2;
/* Test point */
LCDD_Fill(0xFFFFFF);
LCDD_DrawString(30, 50, (uint8_t *)"LCD calibration", COLOR_BLACK);
LCDD_DrawString(1, 100, (uint8_t *)" Touch the point to\nvalidate calibration", COLOR_DARKBLUE);
DrawCalibrationPoint(&testPoint);
/* Wait for touch & end of conversion */
TSD_WaitPenPressed();
TSD_GetRawMeasurement(measuredPoint.data);
TSDCom_InterpolateMeasurement(measuredPoint.data, (uint32_t *) &measuredPoint);
DrawCalibrationPoint(&measuredPoint);
/* Check resulting x and y */
xDiff = (int32_t) measuredPoint.x - (int32_t) testPoint.x;
yDiff = (int32_t) measuredPoint.y - (int32_t) testPoint.y;
xOk = (xDiff >= -POINTS_MAX_ERROR) && (xDiff <= POINTS_MAX_ERROR);
yOk = (yDiff >= -POINTS_MAX_ERROR) && (yDiff <= POINTS_MAX_ERROR);
/* Wait for contact loss */
TSD_WaitPenReleased();
/* Check calibration result */
if (xOk && yOk) {
bCalibrationOk = 1;
LCDD_Fill(COLOR_WHITE);
LCDD_DrawString(30, 50, (uint8_t *)"LCD calibration", COLOR_BLACK);
LCDD_DrawString(80, 140, (uint8_t *)"Success !", COLOR_GREEN);
}
else {
bCalibrationOk = 0;
LCDD_Fill(COLOR_WHITE);
LCDD_DrawString(30, 50, (uint8_t *)"LCD calibration", COLOR_BLACK);
LCDD_DrawString(40, 140, (uint8_t *)"Error too big", COLOR_RED);
}
/* Slight delay */
for (i = 0; i < DELAY_RESULT_DISPLAY; i++);
return (xOk && yOk);
}
//------------------------------------------------------------------------------
/// Performs the calibration process using the provided buffer to display
/// information.
/// \param pLcdBuffer LCD buffer to display.
/// \return True if calibration was successful; otherwise false.
//------------------------------------------------------------------------------
unsigned char TSDCom_Calibrate(void *pLcdBuffer)
{
#ifdef AT91C_ID_LCDC
void *pOldLcdBuffer;
#endif
volatile unsigned int i; // to keep the tempo with gcc code optimisation
signed int slope1, slope2;
CalibrationPoint measuredPoint;
unsigned char xOk, yOk;
signed int xDiff, yDiff;
// Calibration setup
LCDD_Fill(pLcdBuffer, COLOR_WHITE);
LCDD_DrawString(pLcdBuffer, 30, 50, "LCD calibration", COLOR_BLACK);
LCDD_DrawString(pLcdBuffer, 1, 100, " Touch the dots to\ncalibrate the screen", COLOR_DARKBLUE);
#ifdef AT91C_ID_LCDC
pOldLcdBuffer = LCDD_DisplayBuffer(pLcdBuffer);
#endif
// Calibration points
for (i=0; i < 4; i++) {
DrawCalibrationPoint(pLcdBuffer, &calibrationPoints[i]);
// Wait for touch & end of conversion
TSD_WaitPenPressed();
TSD_GetRawMeasurement(calibrationPoints[i].data);
ClearCalibrationPoint(pLcdBuffer, &calibrationPoints[i]);
// Wait for contact loss
TSD_WaitPenReleased();
}
// Calculate slopes using the calibration data
// Theory behind those calculations:
// - We suppose the touchscreen measurements are linear, so the following equations are true (simple
// linear regression) for any two 'a' and 'b' points of the screen:
// dx = (a.data[0] - b.data[0]) / (a.x - b.x)
// dy = (a.data[1] - b.data[1]) / (a.y - b.y)
//
// - We calculate dx and dy (called xslope and yslope here) using the calibration points.
//
// - We can then use dx and dy to infer the position of a point 'p' given the measurements performed
// by the touchscreen ('c' is any of the calibration points):
// dx = (p.data[0] - c.data[0]) / (p.x - c.x)
// dy = (p.data[1] - c.data[1]) / (p.y - c.y)
// Thus:
// p.x = c.x - (p.data[0] - c.data[0]) / dx
// p.y = c.y - (p.data[1] - c.data[1]) / dy
//
// - Since there are four calibration points, dx and dy can be calculated twice, so we average
// the two values.
slope1 = ((signed int) calibrationPoints[0].data[0]) - ((signed int) calibrationPoints[1].data[0]);
slope1 *= 1024;
slope1 /= ((signed int) calibrationPoints[0].x) - ((signed int) calibrationPoints[1].x);
slope2 = ((signed int) calibrationPoints[2].data[0]) - ((signed int) calibrationPoints[3].data[0]);
slope2 *= 1024;
slope2 /= ((signed int) calibrationPoints[2].x) - ((signed int) calibrationPoints[3].x);
xSlope = (slope1 + slope2) / 2;
slope1 = ((signed int) calibrationPoints[0].data[1]) - ((signed int) calibrationPoints[2].data[1]);
slope1 *= 1024;
slope1 /= ((signed int) calibrationPoints[0].y) - ((signed int) calibrationPoints[2].y);
slope2 = ((signed int) calibrationPoints[1].data[1]) - ((signed int) calibrationPoints[3].data[1]);
slope2 *= 1024;
slope2 /= ((signed int) calibrationPoints[1].y) - ((signed int) calibrationPoints[3].y);
ySlope = (slope1 + slope2) / 2;
// Test point
LCDD_Fill(pLcdBuffer, 0xFFFFFF);
LCDD_DrawString(pLcdBuffer, 30, 50, "LCD calibration", COLOR_BLACK);
LCDD_DrawString(pLcdBuffer, 1, 100, " Touch the point to\nvalidate calibration", COLOR_DARKBLUE);
DrawCalibrationPoint(pLcdBuffer, &testPoint);
// Wait for touch & end of conversion
TSD_WaitPenPressed();
TSD_GetRawMeasurement(measuredPoint.data);
TSDCom_InterpolateMeasurement(measuredPoint.data, (unsigned int *) &measuredPoint);
DrawCalibrationPoint(pLcdBuffer, &measuredPoint);
// Check resulting x and y
xDiff = (signed int) measuredPoint.x - (signed int) testPoint.x;
yDiff = (signed int) measuredPoint.y - (signed int) testPoint.y;
xOk = (xDiff >= -POINTS_MAX_ERROR) && (xDiff <= POINTS_MAX_ERROR);
yOk = (yDiff >= -POINTS_MAX_ERROR) && (yDiff <= POINTS_MAX_ERROR);
// Wait for contact loss
TSD_WaitPenReleased();
// Check calibration result
if (xOk && yOk) {
bCalibrationOk = 1;
LCDD_Fill(pLcdBuffer, COLOR_WHITE);
LCDD_DrawString(pLcdBuffer, 30, 50, "LCD calibration", COLOR_BLACK);
LCDD_DrawString(pLcdBuffer, 80, 100, "Success !", COLOR_GREEN);
}
else {
bCalibrationOk = 0;
LCDD_Fill(pLcdBuffer, COLOR_WHITE);
LCDD_DrawString(pLcdBuffer, 30, 50, "LCD calibration", COLOR_BLACK);
LCDD_DrawString(pLcdBuffer, 40, 100, "Error too big", COLOR_RED);
}
// Slight delay
for (i = 0; i < DELAY_RESULT_DISPLAY; i++);
#ifdef AT91C_ID_LCDC
// Restore old LCD buffer
LCDD_DisplayBuffer(pOldLcdBuffer);
#endif
return (xOk && yOk);
}
