uint16_t get_scaled_vcc(void)
{
uint16_t adc_result = 0;
int8_t offset = 0;
offset = ADC_Offset_Get_Unsigned(&ADCB, &(ADCB.CH1), true);
ADC_Wait_8MHz(&ADCB);
ADC_Ch_Conversion_Start(&ADCB.CH1);
while(!ADC_Ch_Conversion_Complete(&ADCB.CH1));
adc_result = ADC_ResultCh_GetWord_Unsigned(&ADCB.CH1, offset);
return adc_result;
}
/**
* Name : adc_init
*
* Synopsis : void adc_init (void)
*
* Description : Initialize the main system clock
*
*/
void adc_init (void)
{
/////////////////FROM XPLAINED 1505////////////////////////////////
// Variable for use when we read the result from an ADC channel
//PORTQ.PIN2CTRL = (PORTQ.PIN2CTRL & ~PORT_OPC_gm) | PORT_OPC_PULLDOWN_gc; // This pin must be grounded to "enable" NTC-resistor
/* Move stored calibration values to ADC B */
ADC_CalibrationValues_Load(&ADCA);
/* Set up ADC A to have signed conversion mode and 8 bit resolution. */
ADC_ConvMode_and_Resolution_Config(&ADCA, true, ADC_RESOLUTION_12BIT_gc);
// The ADC has different voltage reference options, controlled by the REFSEL bits in the
// REFCTRL register. Here the internal reference is selected
ADC_Reference_Config(&ADCA, ADC_REFSEL_VCC_gc);
// The clock into the ADC decides the maximum sample rate and the conversion time, and
// this is controlled by the PRESCALER bits in the PRESCALER register. Here, the
// Peripheral Clock is divided by 8 ( gives 250 KSPS with 2Mhz clock )
ADC_Prescaler_Config(&ADCA, ADC_PRESCALER_DIV8_gc);
// The used Virtual Channel (CH0) must be set in the correct mode
// In this task we will use single ended input, so this mode is selected
/* Setup channel 0 to have single ended input. */
ADC_Ch_InputMode_and_Gain_Config(&ADCA.CH0,
ADC_CH_INPUTMODE_SINGLEENDED_gc,
ADC_CH_GAIN_1X_gc);
ADC_Ch_InputMode_and_Gain_Config(&ADCA.CH1,
ADC_CH_INPUTMODE_SINGLEENDED_gc,
ADC_CH_GAIN_1X_gc);
ADC_Ch_InputMode_and_Gain_Config(&ADCA.CH2,
ADC_CH_INPUTMODE_SINGLEENDED_gc,
ADC_CH_GAIN_1X_gc);
// Setting up the which pins to convert.
// Note that the negative pin is internally connected to ground
//ADC_Ch_InputMux_Config(&ADCB.CH0, ADC_CH_MUXPOS_PIN9_gc, ADC_CH_MUXNEG_PIN1_gc);
ADCA.CH0.MUXCTRL |= ADC_CH_MUXPOS_PIN0_gc;
ADCA.CH1.MUXCTRL |= ADC_CH_MUXPOS_PIN1_gc;
ADCA.CH2.MUXCTRL |= ADC_CH_MUXPOS_PIN2_gc;
// Before the ADC can be used it must be enabled
ADC_Enable(&ADCA);
// Wait until the ADC is ready
ADC_Wait_8MHz(&ADCA);
// In the while(1) loop, a conversion is started on CH0 and the 8 MSB of the result is
// output on the LEDPORT when the conversion is done
/* Get offset value for ADC B. */
adcx.offset = ADC_Offset_Get_Signed(&ADCA, &(ADCA.CH0), true);
adcy.offset = ADC_Offset_Get_Signed(&ADCA, &(ADCA.CH1), true);
adcz.offset = ADC_Offset_Get_Signed(&ADCA, &(ADCA.CH2), true);
}
void adc_init(void)
{
ADC_CalibrationValues_Load(&ADCA);
ADC_ConvMode_and_Resolution_Config(&ADCA,
ADC_ConvMode_Unsigned, ADC_RESOLUTION_12BIT_gc);
ADC_Prescaler_Config(&ADCA, ADC_PRESCALER_DIV16_gc);
ADC_Reference_Config(&ADCA, ADC_REFSEL_VCC_gc);
ADC_Ch_InputMode_and_Gain_Config(&ADCA.CH0,
ADC_CH_INPUTMODE_SINGLEENDED_gc,
ADC_CH_GAIN_1X_gc);
ADC_Ch_InputMux_Config(&ADCA.CH0, ADC_CH_MUXPOS_PIN7_gc, ADC_CH_MUXNEG_PIN0_gc);
ADC_Enable(&ADCA);
ADC_Wait_8MHz(&ADCA);
}
void adc_temp_init(void)
{
// enable 1V reference and temperature modules
ADC_BandgapReference_Enable(&ADCB);
ADC_TempReference_Enable(&ADCB);
// load calibration from signature bytes
ADC_CalibrationValues_Load(&ADCB);
// Conversion mode and resolution (12 bit right-aligned)
ADC_ConvMode_and_Resolution_Config(&ADCB,
ADC_ConvMode_Unsigned, ADC_RESOLUTION_12BIT_gc);
// prescaler from system clock (fastest)
ADC_Prescaler_Config(&ADCB, ADC_PRESCALER_DIV4_gc);
// internal 1V reference
ADC_Reference_Config(&ADCB, ADC_REFSEL_INT1V_gc);
// channel 0 for temperature
ADC_Ch_InputMode_and_Gain_Config(&ADCB.CH0,
ADC_CH_INPUTMODE_INTERNAL_gc,
ADC_CH_GAIN_1X_gc);
ADC_Ch_InputMux_Config(&ADCB.CH0, ADC_CH_MUXINT_TEMP_gc, ADC_CH_MUXNEG_PIN0_gc);
// channel 1 for VCC/10
ADC_Ch_InputMode_and_Gain_Config(&ADCB.CH1,
ADC_CH_INPUTMODE_INTERNAL_gc,
ADC_CH_GAIN_1X_gc);
ADC_Ch_InputMux_Config(&ADCB.CH1, ADC_CH_MUXINT_SCALEDVCC_gc, ADC_CH_MUXNEG_PIN0_gc);
ADC_Enable(&ADCB);
ADC_Wait_8MHz(&ADCB);
}
void InitADC( ADC_t *ADC_Pointer )
{
// Initialize sweep for channel 0, 1, 2 and 3
ADC_SweepChannels_Config( ADC_Pointer, ADC_SWEEP_0123_gc );
// Setup event to start synchronized sweep
ADC_Events_Config( ADC_Pointer, ADC_EVSEL_0123_gc, ADC_EVACT_SYNCHSWEEP_gc );
// Initialize the four channels to convert in single ended mode
ADC_Ch_InputMode_and_Gain_Config( &ADC_Pointer->CH0, ADC_CH_INPUTMODE_SINGLEENDED_gc, ADC_CH_GAIN_1X_gc );
ADC_Ch_InputMode_and_Gain_Config( &ADC_Pointer->CH1, ADC_CH_INPUTMODE_SINGLEENDED_gc, ADC_CH_GAIN_1X_gc );
ADC_Ch_InputMode_and_Gain_Config( &ADC_Pointer->CH2, ADC_CH_INPUTMODE_SINGLEENDED_gc, ADC_CH_GAIN_1X_gc );
ADC_Ch_InputMode_and_Gain_Config( &ADC_Pointer->CH3, ADC_CH_INPUTMODE_SINGLEENDED_gc, ADC_CH_GAIN_1X_gc );
// Route the channels to different pins
// Note that in Single Ended Mode, there is no negative input
ADC_Ch_InputMux_Config( &ADC_Pointer->CH0, ADC_CH_MUXPOS_PIN1_gc, 0 );
ADC_Ch_InputMux_Config( &ADC_Pointer->CH1, ADC_CH_MUXPOS_PIN2_gc, 0 );
ADC_Ch_InputMux_Config( &ADC_Pointer->CH2, ADC_CH_MUXPOS_PIN3_gc, 0 );
ADC_Ch_InputMux_Config( &ADC_Pointer->CH3, ADC_CH_MUXPOS_PIN4_gc, 0 );
// Sample rate is CPUFREQ / 32. @ 2 MHz this equals 62,5ksps
ADC_Prescaler_Config( ADC_Pointer, ADC_PRESCALER_DIV32_gc);
// Set up ADCx to have unsigned conversion mode and 8 bit resolution
ADC_ConvMode_and_Resolution_Config( ADC_Pointer, false, ADC_RESOLUTION_8BIT_gc );
// Set reference voltage on ADCx to be VCC/1.6 V
ADC_Reference_Config( ADC_Pointer, ADC_REFSEL_VCC_gc );
// Enable the ADC
ADC_Enable( ADC_Pointer );
// Wait until common mode voltage is stable. Default clk is 2MHz and
// therefore within the maximum frequency to use this function.
ADC_Wait_8MHz( ADC_Pointer );
}
int main(void)
{
// Add code to sweep CH0 and CH1 in free running mode
// Use the function call in the adc_driver.h
ADC_SweepChannels_Config( &ADCB, ADC_SWEEP_01_gc);
//Enable internal temperature sensor, to be used by CH1
ADC_TempReference_Enable(&ADCB);
// Setup CH1 to have single ended input as in task1 and task2
ADC_Ch_InputMode_and_Gain_Config(&ADCB.CH0,
ADC_CH_INPUTMODE_SINGLEENDED_gc,
ADC_CH_GAIN_1X_gc);
// Set input to CH0 in ADC B to be PIN 1
ADC_Ch_InputMux_Config(&ADCB.CH0,
ADC_CH_MUXPOS_PIN1_gc,
0);
// Setup CH1 to read internal signal
ADC_Ch_InputMode_and_Gain_Config(&ADCB.CH1,
ADC_CH_INPUTMODE_INTERNAL_gc,
ADC_CH_GAIN_1X_gc);
// CH1 is set up to measure the internal temperature sensor
ADC_Ch_InputMux_Config(&ADCB.CH1,
ADC_CH_MUXINT_TEMP_gc,
0);
// Set up ADC B to have unsigned conversion mode and 12 bit resolution
ADC_ConvMode_and_Resolution_Config(&ADCB, false, ADC_RESOLUTION_12BIT_gc);
// Set reference voltage on ADC B to be VCC/1.6 V
ADC_Reference_Config(&ADCB, ADC_REFSEL_VCC_gc);
// Sample rate is CPUFREQ/16.
ADC_Prescaler_Config(&ADCB, ADC_PRESCALER_DIV16_gc);
// Enable ADC B
ADC_Enable(&ADCB);
// Wait until common mode voltage is stable. Default clk is 2MHz and
// therefore within the maximum frequency to use this function.
ADC_Wait_8MHz(&ADCB);
// Enable ADC B free running mode
ADC_FreeRunning_Enable(&ADCB);
// Set the LEDPORT as output
LEDPORT.DIR = 0xFF;
while(1) {
// When CH1IF is set, both conversions are done since CH0 is started first
// Wait for CH1IF to be set
do {
} while ((ADCB.INTFLAGS & ADC_CH1IF_bm) != ADC_CH1IF_bm);
// Clear CH1 Interrupt Flag
ADCB.INTFLAGS |= ADC_CH1IF_bm;
// Read the CH0 result register, 12 bit unsigned (0-4095)
ADC_result_CH0 = ADCB.CH0RES;
// Read the CH1 result register
ADC_result_CH1 = ADCB.CH1RES;
// Shift CH0 result to get the 4 MSB of the input signal on the 4 LSB of the LEDs
ADC_result_CH0 >>= 8;
// Shift CH1 result to get the 4 MSB of the temperature on the 4 MSB of the LEDs
// Also downscale it to 4 bit. Try touching the Xmega to warm it up.
ADC_result_CH1 = ((ADC_result_CH1 - 1) / 16);
ADC_result_CH1 <<= 4;
// Output on the LEDs, the 4 MSB is the internal temperature reading,
// and the 4 LSB is the single ended input reading,
LEDPORT.OUT = ~( (ADC_result_CH1 & 0x00F0) | (ADC_result_CH0 & 0x000F));
}
}
