void pot_init(void) {
//sets up interrupts to trigger on every sucessful conversion
IRQ_ConfigureIT(AT91C_ID_ADC, 0, ISR_ADC);
//initilize ADC
ADC_Initialize(AT91C_BASE_ADC,
AT91C_ID_ADC,
AT91C_ADC_TRGEN_DIS,
0,
AT91C_ADC_SLEEP_NORMAL_MODE,
AT91C_ADC_LOWRES_10_BIT,
BOARD_MCK,
BOARD_ADC_FREQ,
10,
1200);
ADC_EnableDataReadyIt(AT91C_BASE_ADC);
ADC_EnableChannel(AT91C_BASE_ADC, POT_CHANNEL);
IRQ_EnableIT(AT91C_ID_ADC);
ADC_EnableIt(AT91C_BASE_ADC, POT_CHANNEL);
//Starts the adc
ADC_StartConversion(AT91C_BASE_ADC);
}
/**
* 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]);
}
}
static uint32_t _WFE_Potentiometer_Initialize( void )
{
Adc *pAdc = ADC;
int32_t dwLowPotThreshold, dwHighPotThreshold;
/* STEP1: Realize a first measure to get potentiometer's initial position */
/* Initialize ADC*/
ADC_Initialize( pAdc,ID_ADC, ADC_MR_TRGEN_DIS,/*HARDWARE trigger*/
0,ADC_MR_SLEEP_NORMAL,ADC_MR_LOWRES_12_BIT,
BOARD_MCK,BOARD_ADC_FREQ,10,20);
/*Enable channel 5 (potentiometer) */
ADC_EnableChannel(pAdc, ADC_CHANNEL_5);
/* Start convrsion */
ADC_StartConversion(pAdc);
/* Wait for the end of conversion */
while ( !(ADC_GetStatus(pAdc) & ADC_ISR_EOC5) ) {}
/* Get the potentiometer initial value */
gdwPotentiometerValue = ADC_GetConvertedData(pAdc, ADC_CHANNEL_5);
/* Set Window threshold according to the initial values */
dwLowPotThreshold = gdwPotentiometerValue - (NB_INTERVALS * (0x1000 / 256));
if (dwLowPotThreshold < 0)
dwLowPotThreshold = 0;
dwHighPotThreshold = gdwPotentiometerValue + (NB_INTERVALS * (0x1000 / 256));
if (dwHighPotThreshold >= 0x1000)
dwHighPotThreshold = 0x1000 - 1;
/* Normalize the value 0 -> 255 */
gdwPotentiometerValue = (gdwPotentiometerValue * 256) / 0xFFF;
/* STEP2: Re configure ADC to use windowing */
/* Initialize ADC*/
ADC_Initialize( pAdc,ID_ADC, ADC_MR_TRGEN_EN,/*HARDWARE trigger*/
ADC_MR_TRGSEL_ADC_TRIG0,ADC_MR_SLEEP_NORMAL,ADC_MR_LOWRES_12_BIT,
BOARD_MCK,BOARD_ADC_FREQ,10,20);
/*Enable channel 5 (potentiometer) */
ADC_EnableChannel(pAdc, ADC_CHANNEL_5);
/* Configure TC*/
ConfigureTc0();
/*Channel 5 has to be compared*/
ADC_SetCompareChannel(pAdc, ADC_CHANNEL_5);
/*Compare mode, in the window*/
ADC_SetCompareMode(pAdc, ADC_EMR_CMPMODE_OUT);
/* Setup Threshold*/
ADC_SetComparisonWindow(pAdc,((dwHighPotThreshold<<16)|dwLowPotThreshold));
/* enable adc interrupt*/
NVIC_EnableIRQ(ADC_IRQn);
/* Enable Compare Interrupt*/
ADC_EnableIt(pAdc, ADC_IDR_COMPE);
/* Start TC0 and hardware trigger*/
TC_Start(TC0,0);
return SAMGUI_E_OK ;
}
