LED#

Introduction#

The SI91x LED driver is a platform-level software module designed to manage LED control. All LED functions are accessed through the generic driver, which then internally calls the LED-specific functions.

Configuration#

All LED instances are configured with an sl_led_t struct. This struct along with a function definition for initializing LED is automatically generated when an LED is set up using Simplicity Studio's wizard. This struct sl_led_t struct is automatically generated into the following files sl_si91x_led_instances.h and sl_si91x_led_instances.c. The samples below are for a single instance called "led0".

// sl_si91x_led_instances.c

#include "sl_si91x_led.h"
#include "sl_si91x_led_config.h"
#include "sl_si91x_led_instances.h"
sl_led_t const led_led0 = {
 .port = SL_LED_LED0_PORT,
 .pin = SL_LED_LED0_PIN,
 .led_number = SL_LED_LED0_NUMBER,
};

void led_init_instances(void)
{
  sl_si91x_led_init(&led_led0);
}

Note

• The sl_si91x_led_instances.c file is shown with only one instance, but if more were in use they would all appear in this .c file.

// sl_si91x_led_instances.h

#ifndef SL_SI91x_LED_INSTANCES_H
#define SL_SI91x_LED_INSTANCES_H

#include "sl_si91x_led.h"

extern const sl_led_t led_led0;

void led_init_instances(void);

#endif // SL_SI91x_LED_INSTANCES_H

Note

• The sl_si91x_led_instances.h file is shown with only one instance, but if more were in use they would all appear in this .h file.

• For more information on configuring available parameters, see the respective peripheral example readme document and Peripheral Configuration.

Usage#

After the LED structures are defined, the LED functions can be called by passing an instance of sl_led_t, which will internally redirect to the type-specific version of the function. The commonly used functions include the following:

1. It configure GPIOs pertaining to the control of LEDs and to initialize the selected LED GPIO and mode: sl_si91x_led_init

2. This atomically wraps an XOR or a similar operation for a single GPIO pin connected to an LED to toggle the LED: sl_si91x_led_toggle

3. To set a GPIO pin connected to an LED to turn the LED on: sl_si91x_led_set

4. To clear a GPIO pin connected to an LED to turn the LED off: sl_si91x_led_clear

sl_si91x_led_init initialises the specific LED. This function is called automatically when the application is run.

sl_si91x_led_toggle can be implemented by the application, if required. This function is used to toggle the state of the LED. sl_si91x_led_set and sl_si91x_led_clear both can be implemented by the application. These functions are used to turn the LED on and off resectively.