/**
* \brief Measures and enables offset and gain corrections
*/
static void main_adc_correction(void)
{
/* ADC channel configuration structure */
struct adc_channel_config adcch_conf;
uint16_t offset_correction;
/* Expected value for gain correction at 1.9V
* expected_value = Max. range * 1.9V / (VCC / 1.6)
* Max. range = 12 bits signed = 11 bits unsigned
*/
const uint16_t expected_value
= ((1 << 11) * 1900UL) / (3300L * 1000L / 1600L);
/* Captured value for gain correction */
uint16_t captured_value;
/* DAC Output 0 Volt */
main_dac_output(0);
/* Capture value for 0 Volt */
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
offset_correction = adc_get_unsigned_result(&ADCA, ADC_CH0);
/* Enable offset correction */
adcch_read_configuration(&ADCA, ADC_CH0, &adcch_conf);
adcch_enable_correction(&adcch_conf, offset_correction, 1, 1);
adcch_write_configuration(&ADCA, ADC_CH0, &adcch_conf);
/* DAC Output 1.9 Volts */
main_dac_output(1900);
/* Capture value for 1.9 Volts */
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
captured_value = adc_get_unsigned_result(&ADCA, ADC_CH0);
/* Enable offset & gain correction */
adcch_enable_correction(&adcch_conf, offset_correction, expected_value,
captured_value);
adcch_write_configuration(&ADCA, ADC_CH0, &adcch_conf);
printf("\n\rADC correction: ");
printf("Offset correction %d, ", offset_correction);
if (expected_value > captured_value) {
printf("Gain correction 1.%03u\n\r\n\r", (uint16_t)
((((uint32_t)expected_value - captured_value)
* 1000) / captured_value));
} else {
printf("Gain correction 0.%03u\n\r\n\r", (uint16_t)
(((uint32_t)expected_value
* 1000) / captured_value));
}
}
/**
* \brief Reads a 16-bit analog value on ADC channel 0 and returns it.
*
* In this application CH0 is set up to read the analog voltage from
* a simulated thermometer.
*
* \return Temperature of the induction element.
*/
uint16_t ovenctl_get_plate_temperature(void)
{
adc_start_conversion(&ADCA, ADC_CH0);
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
return adc_get_unsigned_result(&ADCA, ADC_CH0) / 4;
}
/**
* \brief Captures a values on ADC
*
* \return value on ADC pins (mV)
*/
static int16_t main_adc_input(void)
{
int16_t sample;
/* Ignore two averaging conversions
* which can include two differents voltage
*/
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
/* Capture averaging */
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
sample = adc_get_signed_result(&ADCA, ADC_CH0);
/* Conversion sample to mV :
* mV = sample * (VCC / 1.6) / Max. range
*/
return ((int32_t)sample * (3300L * 1000L / 1600L)) / (1 << 11);
}
/**
* \internal
* \brief Test averaging conversion in 12-bit mode using the DAC
*
* These values are then measured using the ADC on the pins that are connected
* to the DAC channel, and the results are compared and checked to see if they
* are within the acceptable average of values that passes the test.
*
* \param test Current test case.
*/
static void run_averaging_conversion_test(
const struct test_case *test)
{
int16_t volt_output;
int16_t volt_min, volt_max, volt_input;
/* ADC module configuration structure */
struct adc_config adc_conf;
/* ADC channel configuration structure */
struct adc_channel_config adcch_conf;
adc_disable(&ADCA);
/* Change resolution parameter to accept averaging */
adc_read_configuration(&ADCA, &adc_conf);
adc_set_conversion_parameters(&adc_conf, ADC_SIGN_ON, ADC_RES_MT12,
ADC_REF_VCC);
adc_write_configuration(&ADCA, &adc_conf);
/* Enable averaging */
adcch_read_configuration(&ADCA, ADC_CH0, &adcch_conf);
adcch_enable_averaging(&adcch_conf, ADC_SAMPNUM_1024X);
adcch_write_configuration(&ADCA, ADC_CH0, &adcch_conf);
adc_enable(&ADCA);
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
/* Check values */
for (volt_output = -CONV_MAX_VOLTAGE;
volt_output <= CONV_MAX_VOLTAGE;
volt_output += CONV_VOLTAGE_STEP) {
main_dac_output(volt_output);
/* first capture */
volt_input = main_adc_input();
volt_min = volt_max = volt_input;
/* several capture */
for (uint8_t i = 0; i < 5; i++) {
volt_input = main_adc_input();
if (volt_min > volt_input) {
volt_min = volt_input;
}
if (volt_max < volt_input) {
volt_max = volt_input;
}
}
test_assert_true(test,
(volt_max - volt_min) < CONF_TEST_ACCEPT_DELTA_AVERAGING,
"ADC result is not in acceptable stable range (Min %dmV, Max %dmV)",
volt_min, volt_max);
}
}
/**
* \brief Captures a values on ADC
*
* \return value on ADC pins (mV)
*/
static uint16_t main_adc_input(void)
{
uint16_t sample;
adc_start_conversion(&ADCA, ADC_CH0);
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
sample = adc_get_unsigned_result(&ADCA, ADC_CH0);
/* Conversion sample to mV :
* mV = sample * (VCC / 1.6) / Max. range
*/
return ((uint32_t)sample * (3300L * 1000L / 1600L)) / (1 << 12);
}
/**
* \brief Wrapper function for getting and ADC sample
*
* \param adc_ch which channel to get the ADC samples from
* /returns 16-bit signed ADC result
*/
static int16_t adc_get_sample(uint8_t adc_ch)
{
int16_t result = 0;
adc_start_conversion(&CALIBRATION_ADC, adc_ch);
adc_wait_for_interrupt_flag(&CALIBRATION_ADC, adc_ch);
result = adc_get_result(&CALIBRATION_ADC, adc_ch);
adc_clear_interrupt_flag(&CALIBRATION_ADC, adc_ch);
return result;
}
/**
* \internal
* \brief Measure differential input MUX combinations on channel
*
* Measures a set of input MUX combinations on a single channel, using averaging
* of the number of samples specified with \ref NUM_AVERAGE_SAMPLES.
*
* \pre This function does not configure the ADC, only the ADC channel, and
* therefore the specified ADC needs to be configured before this function
* is run.
*
* \param adc Pointer to ADC to measure with.
* \param ch_mask Mask for channel to measure with.
* \param mux_pos_inputs Pointer to array of positive input MUX settings.
* \param mux_neg_inputs Pointer to array of negative input MUX settings.
* \param num_inputs Number of input MUX setting pairs.
* \param results Pointer to array to store results in.
* \param gain Gain to use for all measurements.
*
* \note The array which \e results points to must have at least \e num_inputs
* elements.
*/
static void differential_signed_average(ADC_t *adc, uint8_t ch_mask,
const uint8_t *mux_pos_inputs, const uint8_t *mux_neg_inputs,
uint8_t num_inputs, int16_t *results, uint8_t gain)
{
struct adc_channel_config adcch_conf;
uint8_t input;
uint8_t i;
int32_t sum;
memset(&adcch_conf, 0, sizeof(struct adc_channel_config));
// Common configuration
adcch_set_interrupt_mode(&adcch_conf, ADCCH_MODE_COMPLETE);
adcch_disable_interrupt(&adcch_conf);
for (input = 0; input < num_inputs; input++) {
adcch_set_input(&adcch_conf, mux_pos_inputs[input],
mux_neg_inputs[input], gain);
adcch_write_configuration(adc, ch_mask, &adcch_conf);
// Enable and do dummy conversion
adc_enable(adc);
adc_start_conversion(adc, ch_mask);
adc_wait_for_interrupt_flag(adc, ch_mask);
// Read an average
sum = 0;
for (i = 0; i < NUM_AVERAGE_SAMPLES; i++) {
adc_start_conversion(adc, ch_mask);
adc_wait_for_interrupt_flag(adc, ch_mask);
sum += (int16_t)adc_get_result(adc, ch_mask);
}
adc_disable(adc);
results[input] = sum / NUM_AVERAGE_SAMPLES;
}
}
int main(void)
{
const usart_serial_options_t usart_serial_options = {
.baudrate = CONF_TEST_BAUDRATE,
.charlength = CONF_TEST_CHARLENGTH,
.paritytype = CONF_TEST_PARITY,
.stopbits = CONF_TEST_STOPBITS,
};
/* Usual initializations */
board_init();
sysclk_init();
sleepmgr_init();
irq_initialize_vectors();
cpu_irq_enable();
stdio_serial_init(CONF_TEST_USART, &usart_serial_options);
printf("\x0C\n\r-- ADC Averaging Example --\n\r");
printf("-- Compiled: %s %s --\n\r\n\r", __DATE__, __TIME__);
printf("Commands:\n\r");
printf("- key 'a' to enable averaging\n\r");
printf("- key 'd' to disable averaging\n\r");
/* ADC initialization */
main_adc_init();
main_adc_averaging_stop();
while (1) {
if (usart_rx_is_complete(CONF_TEST_USART)) {
char key = getchar();
if (key == 'a') {
main_adc_averaging_start();
}
if (key == 'd') {
main_adc_averaging_stop();
}
}
/* Wait sample with or without average */
uint16_t sample;
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
sample = adc_get_unsigned_result(&ADCA, ADC_CH0);
printf("ADC Value: %4u\r", sample);
}
}
int main(void){
char xbeebuffer[100];
int adcSample;
/**Setup Xbee*/
PORTD.DIR = 0b00001000;
PORTF.DIR = 3;
/**Setup interrupts*/
PMIC.CTRL |= PMIC_LOLVLEX_bm | PMIC_MEDLVLEX_bm | PMIC_HILVLEX_bm |
PMIC_LOLVLEN_bm | PMIC_MEDLVLEN_bm | PMIC_HILVLEN_bm;
sei();
USART_InterruptDriver_Initialize(&xbee, &USARTD0, USART_DREINTLVL_LO_gc);
USART_Format_Set(xbee.usart, USART_CHSIZE_8BIT_gc, USART_PMODE_DISABLED_gc, false);
USART_RxdInterruptLevel_Set(xbee.usart, USART_RXCINTLVL_HI_gc);
USART_Baudrate_Set(&USARTD0, 12 , 0);
USART_Rx_Enable(xbee.usart);
USART_Tx_Enable(xbee.usart);
ADC_Ch_InputMode_and_Gain_Config(&ADC_BK.CH0, ADC_CH_INPUTMODE_DIFF_gc, ADC_DRIVER_CH_GAIN_NONE); // differential mode, no gain
ADC_Ch_InputMux_Config(&ADC_BK.CH0, pin, ADC_CH_MUXNEG_PIN1_gc);
ADC_Reference_Config(&ADC_BK, ADC_REFSEL_VCC_gc); // use Vcc/1.6 as ADC reference
ADC_ConvMode_and_Resolution_Config(&ADC_BK, ADC_ConvMode_Signed, ADC_RESOLUTION_12BIT_gc);
ADC_Prescaler_Config(&ADC_BK, ADC_PRESCALER_DIV32_gc);
while(1){
if(readdata){
readdata = 0;
if(input == 'r'){
adc_start_conversion(&ADCA, ADC_CH0);
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
adcSample = adcch_get_signed_result(&ADCA, 0);
sprintf(xbeebuffer, " %d\n\r", adcSample);
sendstring(&xbee, xbeebuffer);
}
}
}
}
/**
* \brief This function get the offset of the ADCB when it is configured
* in signed mode
* \note The ADC must be configured and enabled before this function is run.
* \return Offset on the ADCB
*/
static int8_t adc_offset_get_signed(void)
{
int16_t offset = 0;
uint8_t i;
/* Sum four samples */
for (i = 0; i < 4; i++) {
/* Do one conversion to find offset */
adc_start_conversion(&ADCB, ADC_CH0);
adc_wait_for_interrupt_flag(&ADCB, ADC_CH0);
/* Accumulate conversion results */
offset += adc_get_result(&ADCB, ADC_CH0);
}
/* Return mean value */
return ((int8_t)(offset / 4));
}
/**
* \brief Get mean sample value
*
* Performs 2 to the power of \ref OVERSAMPLING_FACTOR successive conversions,
* and computes the mean value of the resulting sample values.
*
* \return Mean sample value.
*/
static uint16_t get_mean_sample_value(void)
{
uint32_t sum = 0;
uint16_t i;
// Sum the configured number of samples.
for (i = 0; i < (1 << OVERSAMPLING_FACTOR); i++) {
adc_start_conversion(&ADCA, ADC_CH0);
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
sum += adc_get_result(&ADCA, ADC_CH0);
}
// Compute sample mean by scaling down according to oversampling factor.
sum >>= OVERSAMPLING_FACTOR;
return sum;
}
int read_cap_level(uint16_t avg_no) {
int32_t adcresult = 0;
for (uint16_t i = 0; i < avg_no; i++) {
ADC_set_input_config (ADCCH_POS_PIN6); //connect ADC to ADC1 which is shorted to VDD.
ioport_set_pin_dir(TOUCH_ADC_POS_PIN, IOPORT_DIR_OUTPUT);
ioport_set_pin_level(TOUCH_ADC_POS_PIN, false); //set measurement pin to GND
PORTA.PIN0CTRL = PORT_OPC_TOTEM_gc; //totem pole
ioport_set_pin_dir(TOUCH_ADC_POS_PIN, IOPORT_DIR_INPUT); //input
ADC_set_input_config (ADCCH_POS_PIN3); //connect ADC to ADC3 which is sensor previously charged to VDD.
adc_start_conversion(&MY_ADC, CAP_ADC);
adc_wait_for_interrupt_flag(&MY_ADC, CAP_ADC);
adcresult += adc_get_result(&MY_ADC, CAP_ADC);
}
return adcresult / avg_no;
}
/**
* \brief Initialize ADC
*/
static void main_adc_init(void)
{
/* ADC module configuration structure */
struct adc_config adc_conf;
/* ADC channel configuration structure */
struct adc_channel_config adcch_conf;
/* Configure the ADC module:
* - signed, 12-bit results
* - voltage reference = VCC / 1.6 = 3.3V / 1.6
* - 200 kHz maximum clock rate
* - manual conversion triggering
*/
adc_read_configuration(&ADCA, &adc_conf); /* Initialize structures. */
adc_set_conversion_parameters(&adc_conf, ADC_SIGN_ON, ADC_RES_12,
ADC_REF_VCC);
adc_set_clock_rate(&adc_conf, 200000UL);
adc_set_conversion_trigger(&adc_conf, ADC_TRIG_MANUAL, 1, 0);
adc_write_configuration(&ADCA, &adc_conf);
/* Configure ADC channel:
* - differential measurement mode
* - Input voltage V+ is ADC2 pin (PA2 pin)
* - Input voltage V- is ADC3 pin (PA3 pin)
* - 1x gain
* - interrupt flag set on completed conversion
*/
adcch_read_configuration(&ADCA, ADC_CH0, &adcch_conf);
adcch_set_input(&adcch_conf, ADCCH_POS_PIN2, ADCCH_NEG_PIN3, 1);
adcch_set_interrupt_mode(&adcch_conf, ADCCH_MODE_COMPLETE);
adcch_disable_interrupt(&adcch_conf);
adcch_write_configuration(&ADCA, ADC_CH0, &adcch_conf);
/* Enable ADC */
adc_enable(&ADCA);
/* Do useful conversion */
adc_start_conversion(&ADCA, ADC_CH0);
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
}
int read_cap_level_ref(uint16_t avg_no) {
int32_t adcresult = 0;
for (uint16_t i = 0; i < avg_no; i++) {
ADC_set_input_config (ADCCH_POS_PIN6); //connect ADC to ADC1 which is shorted to VDD.
ioport_set_pin_dir(TOUCH_ADC_REF_PIN, IOPORT_DIR_OUTPUT);
ioport_set_pin_level(TOUCH_ADC_REF_PIN, false); //set measurement pin to GND
_delay_us(10); //make sure it is discharged
PORTA.PIN2CTRL = PORT_OPC_TOTEM_gc; //totem pole
ioport_set_pin_dir(TOUCH_ADC_REF_PIN, IOPORT_DIR_INPUT); //input
ADC_set_input_config (ADCCH_POS_PIN2); //connect ADC to ADC2 which is not connected to anything
_delay_us(10);
adc_start_conversion(&MY_ADC, CAP_ADC);
adc_wait_for_interrupt_flag(&MY_ADC, CAP_ADC);
adcresult += adc_get_result(&MY_ADC, CAP_ADC);
}
return adcresult / avg_no;
}
/**
* \brief Enables averaging
*/
static void main_adc_averaging(void)
{
/* ADC module configuration structure */
struct adc_config adc_conf;
/* ADC channel configuration structure */
struct adc_channel_config adcch_conf;
adc_disable(&ADCA);
/* Change resolution parameter to accept averaging */
adc_read_configuration(&ADCA, &adc_conf);
adc_set_conversion_parameters(&adc_conf, ADC_SIGN_ON, ADC_RES_MT12,
ADC_REF_VCC);
adc_write_configuration(&ADCA, &adc_conf);
/* Enable averaging */
adcch_read_configuration(&ADCA, ADC_CH0, &adcch_conf);
adcch_enable_averaging(&adcch_conf, ADC_SAMPNUM_1024X);
adcch_write_configuration(&ADCA, ADC_CH0, &adcch_conf);
adc_enable(&ADCA);
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
}
int main(void)
{
const usart_serial_options_t usart_serial_options = {
.baudrate = CONF_TEST_BAUDRATE,
.charlength = CONF_TEST_CHARLENGTH,
.paritytype = CONF_TEST_PARITY,
.stopbits = CONF_TEST_STOPBITS,
};
char binary[16 + 1];
uint8_t i;
bool oversampling_is_enabled;
/* Usual initializations */
board_init();
sysclk_init();
sleepmgr_init();
irq_initialize_vectors();
cpu_irq_enable();
stdio_serial_init(CONF_TEST_USART, &usart_serial_options);
printf("\x0C\n\r-- ADC Over-sampling Example --\n\r");
printf("-- Compiled: %s %s --\n\r\n\r", __DATE__, __TIME__);
printf("Commands:\n\r");
printf("- key 'o' to enable over-sampling\n\r");
printf("- key 'd' to disable over-sampling\n\r");
/* ADC initializations */
main_adc_init();
main_adc_oversampling_stop();
oversampling_is_enabled = false;
while (1) {
if (usart_rx_is_complete(CONF_TEST_USART)) {
char key = getchar();
if (key == 'o') {
main_adc_oversampling_start();
oversampling_is_enabled = true;
}
if (key == 'd') {
main_adc_oversampling_stop();
oversampling_is_enabled = false;
}
}
/* Wait sample with or without over-sampling */
uint16_t sample;
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
sample = adc_get_unsigned_result(&ADCA, ADC_CH0);
if (!oversampling_is_enabled) {
sample <<= 4;
}
i = 15;
do {
binary[i] = '0' + (sample & 1);
sample >>= 1;
} while (i--);
binary[16] = 0;
printf("ADC Value: %sb\r", binary);
}
}
void alphasense_adc_getValue( void )
{
//ALPHASENSE_STATS * const ps = &g_internal;
struct adc_config adc_conf;
struct adc_channel_config adcch_conf;
uint8_t inputgain = 1;//, elements = 20;
//char szBUF[64];
// DISABLE jtag - it locks the upper 4 pins of PORT B
CCP = CCP_IOREG_gc; // Secret handshake
MCU.MCUCR = 0b00000001;
PORTB.PIN0CTRL = PORT_OPC_TOTEM_gc; // Auxiliary Electrode
PORTB.PIN2CTRL = PORT_OPC_TOTEM_gc; // Working Electrode
PORTB.PIN6CTRL = PORT_OPC_TOTEM_gc; // GND x offset
adc_read_configuration(&ALPHASENSE_ADC, &adc_conf);
adcch_read_configuration(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH, &adcch_conf);
adc_set_conversion_parameters(&adc_conf, ADC_SIGN_OFF, ADC_RES_12, ADC_REF_VCC);
adc_set_conversion_trigger(&adc_conf, ADC_TRIG_MANUAL, 1, 0);
adc_set_clock_rate(&adc_conf, 200000UL);
adc_write_configuration(&ALPHASENSE_ADC, &adc_conf);
adcch_set_input(&adcch_conf, ADCCH_POS_PIN6, ADCCH_NEG_NONE, inputgain);
adcch_write_configuration(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH, &adcch_conf);
adc_enable(&ALPHASENSE_ADC);
adc_start_conversion(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH);
adc_wait_for_interrupt_flag(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH);
adc_start_conversion(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH);
adc_wait_for_interrupt_flag(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH);
const int16_t off = adc_get_result(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH);
adc_disable(&ALPHASENSE_ADC);
//sprintf_P(szBUF,PSTR("Offset: %u\t"),off);
//debug_string(NORMAL,szBUF,false);
//adcch_set_input(&adcch_conf, ADCCH_POS_BANDGAP, ADCCH_NEG_NONE, inputgain);
//adcch_write_configuration(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH, &adcch_conf);
//adc_enable(&ALPHASENSE_ADC);
//adc_start_conversion(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH);
//adc_wait_for_interrupt_flag(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH);
//const uint16_t gain = adc_get_result(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH);
//adc_disable(&ALPHASENSE_ADC);
////sprintf_P(szBUF,PSTR("gain: %u\t"),gain);
////debug_string(NORMAL,szBUF,false);
adcch_set_input(&adcch_conf, ADCCH_POS_PIN0, ADCCH_NEG_NONE, inputgain);
adcch_write_configuration(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH, &adcch_conf);
adc_enable(&ALPHASENSE_ADC);
adc_start_conversion(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH);
adc_wait_for_interrupt_flag(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH);
adc_start_conversion(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH);
adc_wait_for_interrupt_flag(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH);
const int16_t adc_w = adc_get_result(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH)-off;
adc_disable(&ALPHASENSE_ADC);
//sprintf_P(szBUF,PSTR("ADC_WORK: %u\t"),adc_w);
//debug_string(NORMAL,szBUF,false);
adcch_set_input(&adcch_conf, ADCCH_POS_PIN2, ADCCH_NEG_NONE, inputgain);
adcch_write_configuration(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH, &adcch_conf);
adc_enable(&ALPHASENSE_ADC);
adc_start_conversion(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH);
adc_wait_for_interrupt_flag(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH);
adc_start_conversion(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH);
adc_wait_for_interrupt_flag(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH);
const int16_t adc_a = adc_get_result(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH)-off;
adc_disable(&ALPHASENSE_ADC);
//sprintf_P(szBUF,PSTR("ADC_AUX: %u\r\n"),adc_a);
//debug_string(NORMAL,szBUF,false);
//adc_enable(&ALPHASENSE_ADC);
//
//for (int i=0;i<elements;i++)
//{
//adc_start_conversion(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH);
//adc_wait_for_interrupt_flag(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH);
//adc_start_conversion(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH);
//adc_wait_for_interrupt_flag(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH);
//result[i]=adc_get_result(&ALPHASENSE_ADC, ALPHASENSE_ADC_CH);
//
//}
//adc_disable(&ALPHASENSE_ADC);
PORTB.PIN0CTRL = PORT_OPC_PULLUP_gc;
PORTB.PIN2CTRL = PORT_OPC_PULLUP_gc;
PORTB.PIN6CTRL = PORT_OPC_PULLUP_gc;
g_recordingData_Alphasense = true;
g_partialSumWork+=(int32_t)adc_w;
g_partialSumAux+=(int32_t)adc_a;
g_partialCount_Alphasense++;
g_recordingData_Alphasense = false;
//sprintf_P(szBUF,PSTR("Sample: %u\tPartialSumWork: %lu\tPartialSumAux: %lu\r\n"),g_partialCount, g_partialSumWork,g_partialSumAux);
//debug_string(NORMAL,szBUF,false);
//ps->working = adc_w;
//ps->aux = adc_a;
}
/**
* \brief Measures and enables offset and gain corrections
*/
static void main_adc_correction_start(void)
{
/* ADC channel configuration structure */
struct adc_channel_config adcch_conf;
static bool correction_measures_done = false;
static uint16_t offset_correction;
/* Expected value for gain correction at 1.9V
* expected_value = Max. range (12 bits unsigned) * 1.9V / (VCC / 1.6)
*/
const uint16_t expected_value
= ((1 << 12) * 1900UL) / (3300L * 1000L / 1600L);
/* Captured value for gain correction */
static uint16_t captured_value;
if (correction_measures_done) {
goto main_adc_correction_enable;
}
printf("\n\r*Measure offset correction\n\r");
printf("Set PA0 pin to GND and press a key to trigge measurement.\n\r");
printf("Warning on STK600: Remove AREF0 jumper to do it.\n\r");
getchar();
/* Capture value for 0 Volt */
adc_start_conversion(&ADCA, ADC_CH0);
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
offset_correction = adc_get_unsigned_result(&ADCA, ADC_CH0);
/* Enable offset correction */
adcch_read_configuration(&ADCA, ADC_CH0, &adcch_conf);
adcch_enable_correction(&adcch_conf, offset_correction, 1, 1);
adcch_write_configuration(&ADCA, ADC_CH0, &adcch_conf);
printf("*Measure Gain correction\n\r");
printf("Set PA0 pin to 1.9 Volt");
printf(" and press a key to trigge measurement.\r\n");
printf("Reminder on STK600: Set AREF0 jumper to do it.\n\r");
getchar();
/* Capture value for 1.9 Volts */
adc_start_conversion(&ADCA, ADC_CH0);
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
captured_value = adc_get_unsigned_result(&ADCA, ADC_CH0);
correction_measures_done = true;
main_adc_correction_enable:
/* Enable offset & gain correction */
adcch_read_configuration(&ADCA, ADC_CH0, &adcch_conf);
adcch_enable_correction(&adcch_conf, offset_correction, expected_value,
captured_value);
adcch_write_configuration(&ADCA, ADC_CH0, &adcch_conf);
printf("\n\r* ADC correction enabled: ");
printf("Offset correction %d, ", offset_correction);
if (expected_value > captured_value) {
printf("Gain correction 1.%03u\n\r", (uint16_t)
((((uint32_t)expected_value - captured_value)
* 1000) / captured_value));
} else {
printf("Gain correction 0.%03u\n\r", (uint16_t)
(((uint32_t)expected_value
* 1000) / captured_value));
}
}
/**
* \internal
* \brief Test correction conversion in 12-bit mode using the DAC
*
* These values are then measured using the ADC on the pins that are connected
* to the DAC channel, and the results are compared and checked to see if they
* are within the acceptable range of values that passes the test.
*
* \param test Current test case.
*/
static void run_correction_conversion_test(
const struct test_case *test)
{
int16_t volt_output;
int16_t volt_input;
uint16_t error;
/** Measures and enables offset and gain corrections */
/* ADC channel configuration structure */
struct adc_channel_config adcch_conf;
uint16_t offset_correction;
/* Expected value for gain correction at 1.9V
* expected_value = Max. range * 1.9V / (VCC / 1.6)
* Max. range = 12 bits signed = 11 bits unsigned
*/
const uint16_t expected_value
= ((1 << 11) * 1900UL) / (3300L * 1000L / 1600L);
/* Captured value for gain correction */
uint16_t captured_value;
/* DAC Output 0 Volt */
main_dac_output(0);
/* Capture value for 0 Volt */
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
offset_correction = adc_get_unsigned_result(&ADCA, ADC_CH0);
/* Enable offset correction */
adcch_read_configuration(&ADCA, ADC_CH0, &adcch_conf);
adcch_enable_correction(&adcch_conf, offset_correction, 1, 1);
adcch_write_configuration(&ADCA, ADC_CH0, &adcch_conf);
/* DAC Output 1.9 Volts */
main_dac_output(1900);
/* Capture value for 1.9 Volts */
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
captured_value = adc_get_unsigned_result(&ADCA, ADC_CH0);
/* Enable offset & gain correction */
adcch_enable_correction(&adcch_conf, offset_correction, expected_value,
captured_value);
adcch_write_configuration(&ADCA, ADC_CH0, &adcch_conf);
/* Check values */
for (volt_output = -CONV_MAX_VOLTAGE;
volt_output <= CONV_MAX_VOLTAGE;
volt_output += CONV_VOLTAGE_STEP) {
main_dac_output(volt_output);
volt_input = main_adc_input();
if (volt_output > volt_input) {
error = volt_output - volt_input;
} else {
error = volt_input - volt_output;
}
test_assert_true(test,
error < CONF_TEST_ACCEPT_DELTA_CORRECTION,
"ADC result is outside acceptable range (expected %d, captured %d)",
volt_output, volt_input);
}
}
int main(void)
{
struct adc_config adc_conf;
struct adc_channel_config adcch_conf;
board_init();
sysclk_init();
sleepmgr_init();
irq_initialize_vectors();
cpu_irq_enable();
// Initialize configuration structures.
adc_read_configuration(&ADCA, &adc_conf);
adcch_read_configuration(&ADCA, ADC_CH0, &adcch_conf);
/* Configure the ADC module:
* - unsigned, 12-bit results
* - bandgap (1 V) voltage reference
* - 200 kHz maximum clock rate
* - manual conversion triggering
*/
adc_set_conversion_parameters(&adc_conf, ADC_SIGN_OFF, ADC_RES_12,
ADC_REF_BANDGAP);
adc_set_clock_rate(&adc_conf, 200000UL);
adc_set_conversion_trigger(&adc_conf, ADC_TRIG_MANUAL, 1, 0);
adc_write_configuration(&ADCA, &adc_conf);
/* Configure ADC channel 0:
* - single-ended measurement from configured input pin
* - interrupt flag set on completed conversion
*/
adcch_set_input(&adcch_conf, INPUT_PIN, ADCCH_NEG_NONE,
1);
adcch_set_interrupt_mode(&adcch_conf, ADCCH_MODE_COMPLETE);
adcch_disable_interrupt(&adcch_conf);
adcch_write_configuration(&ADCA, ADC_CH0, &adcch_conf);
// Enable the ADC and do one dummy conversion.
adc_enable(&ADCA);
adc_start_conversion(&ADCA, ADC_CH0);
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
// Light up LED 1, wait for button press.
ioport_set_pin_low(LED1_PIN);
wait_for_button();
// Perform oversampling of offset.
cal_data.offset = get_mean_sample_value();
// Light up LED 2, wait for button press.
ioport_set_pin_low(LED2_PIN);
wait_for_button();
// Perform oversampling of 0.9 V for gain calibration.
cal_data.gain = get_mean_sample_value() - cal_data.offset;
// Turn off LEDs.
ioport_set_pin_high(LED1_PIN);
ioport_set_pin_high(LED2_PIN);
// Enable interrupts on ADC channel, then trigger first conversion.
adcch_enable_interrupt(&adcch_conf);
adcch_write_configuration(&ADCA, ADC_CH0, &adcch_conf);
adc_start_conversion(&ADCA, ADC_CH0);
do {
// Sleep until ADC interrupt triggers.
sleepmgr_enter_sleep();
} while (1);
}
