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);
}
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));
}
}
