Unit tests for ADC driver using DAC.

#include <stdint.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <asf.h>
#include <conf_test.h>

Macros
ADC unit test definitions
#define	NUM_AVERAGE_SAMPLES 4
	Number of samples to average over. More...

#define	NUM_CHANNELS 4
	Number of ADC channels to use. More...

#define	DAC_MIN 0
	Minimum value for DAC. More...

#define	DAC_MAX 0xfff
	Maximum value for DAC. More...

#define	ADC_ZERO 0
	ADC zero value. More...

#define	ADC_UNSIGNED_8BIT_MAX 0xff
	Maximum value for ADC in unsigned 8-bit. More...

#define	ADC_UNSIGNED_12BIT_MAX 0xfff
	Maximum value for ADC in unsigned 12-bit. More...

#define	ADC_SIGNED_12BIT_MAX 0x7ff
	Maximum value for ADC in signed 12-bit. More...

#define	ADC_SIGNED_12BIT_MIN -0x800
	Minimum value for ADC in signed 12-bit. More...

Functions
int	main (void)
	Run ADC unit tests. More...

ADC unit test helper functions
static void	single_ended_unsigned_average (ADC_t adc, uint8_t ch_mask, const uint8_t mux_inputs, uint8_t num_inputs, uint16_t *results)
	Measure single-ended input MUX combinations on channel. More...

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)
	Measure differential input MUX combinations on channel. More...

static void	verify_unsigned_result (const struct test_case *test, uint16_t expected, uint16_t actual, uint8_t dac_ch, uint8_t adc_ch, uint8_t mux_input, uint16_t upper_limit, bool value_is_12bit)
	Verify that unsigned ADC result is in acceptable range. More...

static void	verify_signed_result (const struct test_case *test, int16_t expected, int16_t actual, uint8_t adc_ch, uint8_t mux_pos_input, uint8_t mux_neg_input, int16_t lower_limit, int16_t upper_limit, uint8_t gain, bool value_is_12bit)
	Verify that unsigned ADC result is in acceptable range. More...

ADC unit test functions
static void	run_single_ended_12bit_conversion_test (const struct test_case *test)
	Test single ended conversion in 12-bit mode using the DAC. More...

static void	run_single_ended_8bit_conversion_test (const struct test_case *test)
	Test single ended conversion in 8-bit mode using the DAC. More...

static void	run_differential_12bit_conversion_test (const struct test_case *test)
	Test differential conversion in 12-bit mode using the DAC. More...

static void	run_differential_12bit_with_gain_conversion_test (const struct test_case *test)
	Test differential conversion with gain in 12-bit mode using the DAC. More...

#define ADC_SIGNED_12BIT_MAX 0x7ff

Maximum value for ADC in signed 12-bit.

Referenced by run_differential_12bit_conversion_test(), and run_differential_12bit_with_gain_conversion_test().

#define ADC_SIGNED_12BIT_MIN -0x800

Minimum value for ADC in signed 12-bit.

Referenced by run_differential_12bit_conversion_test(), and run_differential_12bit_with_gain_conversion_test().

#define ADC_UNSIGNED_12BIT_MAX 0xfff

Maximum value for ADC in unsigned 12-bit.

Referenced by run_single_ended_12bit_conversion_test().

#define ADC_UNSIGNED_8BIT_MAX 0xff

Maximum value for ADC in unsigned 8-bit.

Referenced by run_single_ended_8bit_conversion_test().

#define ADC_ZERO 0

ADC zero value.

Referenced by run_differential_12bit_conversion_test(), run_single_ended_12bit_conversion_test(), and run_single_ended_8bit_conversion_test().

#define DAC_MAX 0xfff

Maximum value for DAC.

Referenced by run_differential_12bit_conversion_test(), run_differential_12bit_with_gain_conversion_test(), run_single_ended_12bit_conversion_test(), and run_single_ended_8bit_conversion_test().

#define DAC_MIN 0

Minimum value for DAC.

Referenced by run_differential_12bit_conversion_test(), run_differential_12bit_with_gain_conversion_test(), run_single_ended_12bit_conversion_test(), and run_single_ended_8bit_conversion_test().

#define NUM_AVERAGE_SAMPLES 4

Number of samples to average over.

Referenced by differential_signed_average(), and single_ended_unsigned_average().

#define NUM_CHANNELS 4

Number of ADC channels to use.

Referenced by run_differential_12bit_conversion_test(), run_differential_12bit_with_gain_conversion_test(), run_single_ended_12bit_conversion_test(), and run_single_ended_8bit_conversion_test().

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
	)

static

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 NUM_AVERAGE_SAMPLES.

Precondition: 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.

Parameters

adc	Pointer to ADC to measure with.
ch_mask	Mask for channel to measure with.
mux_pos_inputs	Pointer to array of positive input MUX settings.
mux_neg_inputs	Pointer to array of negative input MUX settings.
num_inputs	Number of input MUX setting pairs.
results	Pointer to array to store results in.
gain	Gain to use for all measurements.

Note: The array which results points to must have at least num_inputs elements.

References adc_disable(), adc_enable(), adc_get_result, adc_start_conversion(), adc_wait_for_interrupt_flag(), adcch_disable_interrupt(), ADCCH_MODE_COMPLETE, adcch_set_input(), adcch_set_interrupt_mode(), adcch_write_configuration(), and NUM_AVERAGE_SAMPLES.

Referenced by run_differential_12bit_conversion_test(), and run_differential_12bit_with_gain_conversion_test().

int main ( void )

Run ADC unit tests.

Initializes the clock system, board and serial output, then sets up the ADC unit test suite and runs it.

References usart_rs232_options::baudrate, board_init(), DEFINE_TEST_ARRAY, DEFINE_TEST_CASE, DEFINE_TEST_SUITE, run_differential_12bit_conversion_test(), run_differential_12bit_with_gain_conversion_test(), run_single_ended_12bit_conversion_test(), run_single_ended_8bit_conversion_test(), sleepmgr_init(), stdio_serial_init(), sysclk_init(), test_suite_run(), and usart_serial_options.

static void run_differential_12bit_conversion_test ( const struct test_case * test )

static

Test differential conversion in 12-bit mode using the DAC.

This tests output three different values on the two DAC channels:

1/2 * DAC_MAX on both outputs to get a differential zero
DAC_MAX on positive and DAC_MIN on negative to get max positive result
DAC_MIN on positive and DAC_MAX on negative to get max negative result

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.

Parameters

test	Current test case.

References adc_read_configuration(), ADC_REF_BANDGAP, ADC_RES_12, adc_set_clock_rate(), adc_set_conversion_parameters(), adc_set_conversion_trigger(), ADC_SIGN_ON, ADC_SIGNED_12BIT_MAX, ADC_SIGNED_12BIT_MIN, ADC_TRIG_MANUAL, adc_write_configuration(), ADC_ZERO, DAC_ADJ_RIGHT, DAC_CH0, DAC_CH1, dac_enable(), DAC_MAX, DAC_MIN, dac_read_configuration(), DAC_REF_BANDGAP, dac_set_active_channel(), dac_set_channel_value(), dac_set_conversion_interval(), dac_set_conversion_parameters(), dac_set_conversion_trigger(), dac_set_refresh_interval(), dac_wait_for_channel_ready(), dac_write_configuration(), differential_signed_average(), NUM_CHANNELS, and verify_signed_result().

Referenced by main().

static void run_differential_12bit_with_gain_conversion_test ( const struct test_case * test )

static

Test differential conversion with gain in 12-bit mode using the DAC.

This test outputs a gain compensated level on DAC output that should result in a value of half maximum positive value on the ADC.

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.

Parameters

test	Current test case.

References adc_read_configuration(), ADC_REF_BANDGAP, ADC_RES_12, adc_set_clock_rate(), adc_set_conversion_parameters(), adc_set_conversion_trigger(), ADC_SIGN_ON, ADC_SIGNED_12BIT_MAX, ADC_SIGNED_12BIT_MIN, ADC_TRIG_MANUAL, adc_write_configuration(), DAC_ADJ_RIGHT, DAC_CH0, DAC_CH1, dac_enable(), DAC_MAX, DAC_MIN, dac_read_configuration(), DAC_REF_BANDGAP, dac_set_active_channel(), dac_set_channel_value(), dac_set_conversion_interval(), dac_set_conversion_parameters(), dac_set_conversion_trigger(), dac_set_refresh_interval(), dac_wait_for_channel_ready(), dac_write_configuration(), differential_signed_average(), NUM_CHANNELS, and verify_signed_result().

Referenced by main().

static void run_single_ended_12bit_conversion_test ( const struct test_case * test )

static

Test single ended conversion in 12-bit mode using the DAC.

This tests output three different values on the two DAC channels:

0 (output analog value is greater than 0, as the DAC cannot go that low)
1/2 * DAC_MAX Half of the maximum value of the DAC
DAC_MAX The maximum value (VREF) of 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.

Parameters

test	Current test case.

References adc_read_configuration(), ADC_REF_BANDGAP, ADC_RES_12, adc_set_clock_rate(), adc_set_conversion_parameters(), adc_set_conversion_trigger(), ADC_SIGN_OFF, ADC_TRIG_MANUAL, ADC_UNSIGNED_12BIT_MAX, adc_write_configuration(), ADC_ZERO, DAC_ADJ_RIGHT, DAC_CH0, DAC_CH1, dac_enable(), DAC_MAX, DAC_MIN, dac_read_configuration(), DAC_REF_BANDGAP, dac_set_active_channel(), dac_set_channel_value(), dac_set_conversion_interval(), dac_set_conversion_parameters(), dac_set_conversion_trigger(), dac_set_refresh_interval(), dac_wait_for_channel_ready(), dac_write_configuration(), NUM_CHANNELS, single_ended_unsigned_average(), and verify_unsigned_result().

Referenced by main().

static void run_single_ended_8bit_conversion_test ( const struct test_case * test )

static

Test single ended conversion in 8-bit mode using the DAC.

This tests output three different values on the two DAC channels:

0 (output analog value is greater than 0, as the DAC cannot go that low)
1/2 * DAC_MAX Half of the maximum value of the DAC
DAC_MAX The maximum value (VREF) of the DAC.

These values are then measured using the ADC on the pins that are connected to the DAC channel, using all available ADC channels and the results are compared and checked to see if they are within the acceptable range of values that passes the test.

Parameters

test	Current test case.

References adc_read_configuration(), ADC_REF_BANDGAP, ADC_RES_8, adc_set_clock_rate(), adc_set_conversion_parameters(), adc_set_conversion_trigger(), ADC_SIGN_OFF, ADC_TRIG_MANUAL, ADC_UNSIGNED_8BIT_MAX, adc_write_configuration(), ADC_ZERO, DAC_ADJ_RIGHT, DAC_CH0, DAC_CH1, dac_enable(), DAC_MAX, DAC_MIN, dac_read_configuration(), DAC_REF_BANDGAP, dac_set_active_channel(), dac_set_channel_value(), dac_set_conversion_interval(), dac_set_conversion_parameters(), dac_set_conversion_trigger(), dac_set_refresh_interval(), dac_wait_for_channel_ready(), dac_write_configuration(), NUM_CHANNELS, single_ended_unsigned_average(), and verify_unsigned_result().

Referenced by main().

static void single_ended_unsigned_average	(	ADC_t *	adc,
		uint8_t	ch_mask,
		const uint8_t *	mux_inputs,
		uint8_t	num_inputs,
		uint16_t *	results
	)

static

Measure single-ended 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 NUM_AVERAGE_SAMPLES.

Precondition: 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.

Parameters

adc	Pointer to ADC to measure with.
ch_mask	Mask for channel to measure with.
mux_inputs	Pointer to array of input MUX settings.
num_inputs	Number of input MUX settings.
results	Pointer to array to store results in.

Note: The array which results points to must have at least num_inputs elements.

References adc_disable(), adc_enable(), adc_get_result, adc_start_conversion(), adc_wait_for_interrupt_flag(), adcch_disable_interrupt(), ADCCH_MODE_COMPLETE, ADCCH_NEG_NONE, adcch_set_input(), adcch_set_interrupt_mode(), adcch_write_configuration(), and NUM_AVERAGE_SAMPLES.

Referenced by run_single_ended_12bit_conversion_test(), and run_single_ended_8bit_conversion_test().

static void verify_signed_result	(	const struct test_case *	test,
		int16_t	expected,
		int16_t	actual,
		uint8_t	adc_ch,
		uint8_t	mux_pos_input,
		uint8_t	mux_neg_input,
		int16_t	lower_limit,
		int16_t	upper_limit,
		uint8_t	gain,
		bool	value_is_12bit
	)

static

Verify that unsigned ADC result is in acceptable range.

Checks that measurement is within the expected range, and outputs a clear error message to the unit test framework if it is not.

Parameters

test	Pointer to current test case.
expected	The expected ADC result.
actual	The measured ADC result.
adc_ch	The ADC channel used.
mux_pos_input	The positive ADC input MUX setting used.
mux_neg_input	The negative ADC input MUX setting used.
lower_limit	Lower limit of accepted range, can override the limit implicitly given by the accepted deviation.
upper_limit	Upper limit of accepted range, can override the limit implicitly given by the accepted deviation.
gain	ADC input gain setting used.
value_is_12bit	Specify the resolution of the ADC result and thus the accepted deviation: `true` for +/- CONF_TEST_ACCEPT_DELTA_12BIT `false` for +/- CONF_TEST_ACCEPT_DELTA_8BIT

References test_assert_true.

Referenced by run_differential_12bit_conversion_test(), and run_differential_12bit_with_gain_conversion_test().

static void verify_unsigned_result	(	const struct test_case *	test,
		uint16_t	expected,
		uint16_t	actual,
		uint8_t	dac_ch,
		uint8_t	adc_ch,
		uint8_t	mux_input,
		uint16_t	upper_limit,
		bool	value_is_12bit
	)

static

Verify that unsigned ADC result is in acceptable range.

Checks that measurement is within the expected range, and outputs a clear error message to the unit test framework if it is not.

Parameters

test	Pointer to current test case.
expected	The expected ADC result.
actual	The measured ADC result.
dac_ch	The DAC channel used.
adc_ch	The ADC channel used.
mux_input	The ADC input MUX setting used.
upper_limit	Upper limit of accepted range, can override the limit implicitly given by the accepted deviation.
value_is_12bit	Specify the resolution of the ADC result and thus the accepted deviation: `true` for +/- CONF_TEST_ACCEPT_DELTA_12BIT `false` for +/- CONF_TEST_ACCEPT_DELTA_8BIT

References test_assert_true.

Referenced by run_single_ended_12bit_conversion_test(), and run_single_ended_8bit_conversion_test().

Microchip® Advanced Software Framework

Macros

Functions