Development

1. Complete the operations described in Getting Started with Hi3861.

   LED control examples are stored in the file applications/sample/wifi-iot/app/iothardware/led_example.c.

2. Understand the cable connections by referring to the schematic diagram. The LED is connected to the function multiplexing pin WIFI_IOT_IO_NAME_GPIO_9.

   NOTE: For details about the schematic diagram of the development board, contact the Hi3861 customer service personnel.

3. Initialize the GPIO pin, specify the pin usage, and create a task to turn on or off the LED periodically so that the LED blinks.

   static void LedExampleEntry(void)
   {
       osThreadAttr_t attr;
   
       /* Initialize the GPIO pin. */
       GpioInit();
       /* Configure GPIO pin 9. */
       IoSetFunc(WIFI_IOT_IO_NAME_GPIO_9, WIFI_IOT_IO_FUNC_GPIO_9_GPIO);
       /* Set pin 9 as the output direction. */
       GpioSetDir(WIFI_IOT_IO_NAME_GPIO_9, WIFI_IOT_GPIO_DIR_OUT);
   
       attr.name = "LedTask";
       attr.attr_bits = 0U;
       attr.cb_mem = NULL;
       attr.cb_size = 0U;
       attr.stack_mem = NULL;
       attr.stack_size = LED_TASK_STACK_SIZE;
       attr.priority = LED_TASK_PRIO;
   
       /* Start the task. */
       if (osThreadNew((osThreadFunc_t)LedTask, NULL, &attr) == NULL) {
           printf("[LedExample] Falied to create LedTask!\n");
       }
   }

4. Use a cyclic task in which the LED periodically turns on and off to implement LED blinking.

   static void *LedTask(const char *arg)
   {
       (void)arg;
       while (1) {
           switch (g_ledState) {
               case LED_ON:
                   GpioSetOutputVal(WIFI_IOT_IO_NAME_GPIO_9, 1);
                   usleep(LED_INTERVAL_TIME_US);
                   break;
               case LED_OFF:
                   GpioSetOutputVal(WIFI_IOT_IO_NAME_GPIO_9, 0);
                   usleep(LED_INTERVAL_TIME_US);
                   break;
               case LED_SPARK:
                   GpioSetOutputVal(WIFI_IOT_IO_NAME_GPIO_9, 0);
                   usleep(LED_INTERVAL_TIME_US);
                   GpioSetOutputVal(WIFI_IOT_IO_NAME_GPIO_9, 1);
                   usleep(LED_INTERVAL_TIME_US);
                   break;
               default:
                   usleep(LED_INTERVAL_TIME_US);
                   break;
           }
       }
       return NULL;
   }

5. Call SYS_RUN() of OpenHarmony to start the service. (SYS_RUN is defined in the ohos_init.h file.)

   SYS_RUN(LedExampleEntry);

6. Change the applications/sample/wifi-iot/app/BUILD.gn file to enable led_example.c to participate in compilation.

   import("//build/lite/config/component/lite_component.gni")
   lite_component("app") {
       features = [
           "iothardware:led_example"
       ]
   }