1.8.2.1.3 Workflow

Create an AC device instance struct, which will be associated with an Analog Comparator peripheral hardware instance.

static struct ac_module ac_instance;

Define a macro to select the comparator channel that will be sampled, for convenience.

#define AC_COMPARATOR_CHANNEL   AC_CHAN_CHANNEL_0

Create a new function configure_ac(), which will be used to configure the overall Analog Comparator peripheral.

void configure_ac(void)
{

Create an Analog Comparator peripheral configuration structure that will be filled out to set the module configuration.

struct ac_config config_ac;

Fill the Analog Comparator peripheral configuration structure with the default module configuration values.

ac_get_config_defaults(&config_ac);

Initialize the Analog Comparator peripheral and associate it with the software instance structure that was defined previously.

ac_init(&ac_instance, AC, &config_ac);

Create a new function configure_ac_channel(), which will be used to configure the overall Analog Comparator peripheral.

void configure_ac_channel(void)
{

Create an Analog Comparator channel configuration structure that will be filled out to set the channel configuration.

struct ac_chan_config config_ac_chan;

Fill the Analog Comparator channel configuration structure with the default channel configuration values.

ac_chan_get_config_defaults(&config_ac_chan);

Alter the channel configuration parameters to set the channel to one-shot mode, with the correct negative and positive MUX selections and the desired voltage scaler.

Select when the interrupt should occur. In this case an interrupt will occur at every finished conversion.

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;

Configure the physical pin that will be routed to the AC module channel 0.

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 = CONF_AC_MUX;
system_pinmux_pin_set_config(CONF_AC_PIN, &ac0_pin_conf);

Initialize the Analog Comparator channel and configure it with the desired settings.

ac_chan_set_config(&ac_instance, AC_COMPARATOR_CHANNEL, &config_ac_chan);

Enable the initialized Analog Comparator channel.

ac_chan_enable(&ac_instance, AC_COMPARATOR_CHANNEL);

Create a new callback function.

void callback_function_ac(struct ac_module *const module_inst)
{
    callback_status = true;
}

Create a callback status software flag.

bool volatile callback_status = false;

Let the callback function set the calback_status flag to true.

callback_status = true;

Create a new function configure_ac_callback(), which will be used to configure the callbacks.

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);
}

Register callback function.

ac_register_callback(&ac_instance, callback_function_ac, AC_CALLBACK_COMPARATOR_0);

Enable the callbacks.

ac_enable_callback(&ac_instance, AC_CALLBACK_COMPARATOR_0);

Enable the now initialized Analog Comparator peripheral.

ac_enable(&ac_instance);