Quick Start Guide for SAM4L Analog Comparator Driver

This is the quick start guide for the SAM4L Analog Comparator Interface Controller (ACIFC) Driver, with step-by-step instructions on how to configure and use the driver in a selection of use cases.

The use cases contain several code fragments. The code fragments in the steps for setup can be copied into a custom initialization function, while the steps for usage can be copied into, e.g., the main application function.

Basic Use Case

In this basic use case ACIFC channel 0 is configured to compare the inputs from ACAP0 and ACAN0.

Prerequisites

• System Clock Management (SysClock)

Setup Steps

Example Code

Enable the following macros in the header file conf_clock.h:

#define CONFIG_SYSCLK_SOURCE       SYSCLK_SRC_DFLL 

#define CONFIG_DFLL0_SOURCE        GENCLK_SRC_OSC32K 

Add the following code to your application C-file:

sysclk_init(); 

Workflow

1. Set system clock source as DFLL:

   #define CONFIG_SYSCLK_SOURCE       SYSCLK_SRC_DFLL 

2. Set DFLL source as OSC32K:

   #define CONFIG_DFLL0_SOURCE        GENCLK_SRC_OSC32K 

3. Initialize the system clock:

   sysclk_init(); 

Usage Steps

Example Code

Add the following to, for example, the main loop in your application C-file:

#define EXAMPLE_AC_CHANNEL         0

struct ac_dev_inst ac_device;

    struct ac_config module_cfg;
    ac_get_config_defaults(&module_cfg);
    ac_init(&ac_device, ACIFC, &module_cfg);

    ac_enable(&ac_device);

    struct ac_ch_config ch_cfg;
    ac_ch_get_config_defaults(&ch_cfg);
    ch_cfg.always_on = true;
    ch_cfg.fast_mode = true;
    ac_ch_set_config(&ac_device, EXAMPLE_AC_CHANNEL, &ch_cfg);

while (!ac_is_comparison_done(&ac_device)); 

Workflow

1. Get the default configuration and initialize the module:

       struct ac_config module_cfg;
       ac_get_config_defaults(&module_cfg);
       ac_init(&ac_device, ACIFC, &module_cfg);

2. Enable the module:

   ac_enable(&ac_device); 

3. Get the default configuration to initialize channel 0:

   
   #define EXAMPLE_AC_CHANNEL         0

       struct ac_ch_config ch_cfg;
       ac_ch_get_config_defaults(&ch_cfg);
       ch_cfg.always_on = true;
       ch_cfg.fast_mode = true;
       ac_ch_set_config(&ac_device, EXAMPLE_AC_CHANNEL, &ch_cfg);

4. Start a single comparison:

   ac_user_trigger_single_comparison(&ac_device); 

5. Check if the comparison has completed:

   while (!ac_is_comparison_done(&ac_device));