1.8.1.1.3 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 ac_chan_conf;

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

ac_chan_get_config_defaults(&ac_chan_conf);

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.

ac_chan_conf.sample_mode      = AC_CHAN_MODE_SINGLE_SHOT;
ac_chan_conf.positive_input   = AC_CHAN_POS_MUX_PIN0;
ac_chan_conf.negative_input   = AC_CHAN_NEG_MUX_SCALED_VCC;
ac_chan_conf.vcc_scale_factor = 32;

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, &ac_chan_conf);

Enable the now initialized Analog Comparator channel.

ac_chan_enable(&ac_instance, AC_COMPARATOR_CHANNEL);

Enable the now initialized Analog Comparator peripheral.

ac_enable(&ac_instance);