SAML21走起10:AC模拟比较器CALLBACK模式

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#include <asf.h>

/* AC module software instance (must not go out of scope while in use). */

static struct ac_module ac_instance;



/* Comparator channel that will be used. */

#define AC_COMPARATOR_CHANNEL AC_CHAN_CHANNEL_0



void configure_ac(void);

void configure_ac_channel(void);

void callback_function_ac(struct ac_module *const module_inst);

void configure_ac_callback(void);



uint8_t callback_status;



void configure_ac(void)

{ 

/* Create a new configuration structure for the Analog Comparator settings * and fill with the default module settings. */ 

struct ac_config config_ac;

ac_get_config_defaults(&config_ac);

/* Alter any Analog Comparator configuration settings here if required. */

/* Initialize and enable the Analog Comparator with the user settings. */ 

ac_init(&ac_instance, AC, &config_ac);}

void configure_ac_channel(void)

{ 

/* Create a new configuration structure for the Analog Comparator channel * settings and fill with the default module channel settings. */

struct ac_chan_config config_ac_chan;

ac_chan_get_config_defaults(&config_ac_chan);

/* Set the Analog Comparator channel configuration settings. */

config_ac_chan.sample_mode = AC_CHAN_MODE_SINGLE_SHOT;

config_ac_chan.positive_input = AC_CHAN_POS_MUX_PIN0;

config_ac_chan.negative_input = AC_CHAN_NEG_MUX_SCALED_VCC; 

config_ac_chan.vcc_scale_factor = 32;

config_ac_chan.interrupt_selection = AC_CHAN_INTERRUPT_SELECTION_END_OF_COMPARE;

/* Set up a pin as an AC channel input. */

struct system_pinmux_config ac0_pin_conf;

system_pinmux_get_config_defaults(&ac0_pin_conf);

ac0_pin_conf.direction = SYSTEM_PINMUX_PIN_DIR_INPUT;

ac0_pin_conf.mux_position = MUX_PA04B_AC_AIN0;

system_pinmux_pin_set_config(PIN_PA04B_AC_AIN0, &ac0_pin_conf);

/* Initialize and enable the Analog Comparator channel with the user * settings. */

ac_chan_set_config(&ac_instance, AC_COMPARATOR_CHANNEL, &config_ac_chan);

ac_chan_enable(&ac_instance, AC_COMPARATOR_CHANNEL);}

void callback_function_ac(struct ac_module *const module_inst)

{ callback_status = true;}

void configure_ac_callback(void)

{ ac_register_callback(&ac_instance, callback_function_ac, AC_CALLBACK_COMPARATOR_0);

ac_enable_callback(&ac_instance, AC_CALLBACK_COMPARATOR_0);}













int main (void)

{



system_init();

configure_ac();

configure_ac_channel();

configure_ac_callback();

ac_enable(&ac_instance);

ac_chan_trigger_single_shot(&ac_instance, AC_COMPARATOR_CHANNEL);

uint8_t last_comparison = AC_CHAN_STATUS_UNKNOWN;

port_pin_set_output_level(LED_0_PIN, true);

while (true)

{

if (callback_status == true)

{ 

do

{

last_comparison = ac_chan_get_status(&ac_instance, AC_COMPARATOR_CHANNEL);

} while (last_comparison & AC_CHAN_STATUS_UNKNOWN);

port_pin_set_output_level(LED_0_PIN, (last_comparison & AC_CHAN_STATUS_NEG_ABOVE_POS));

callback_status = false;

ac_chan_trigger_single_shot(&ac_instance, AC_COMPARATOR_CHANNEL);

}

}





}