Openharmony quick start

To write Helloworld

Create folder

stay [git clone In the directory ]bearpi-hm_nano\applications\BearPi\BearPi-HM_Nano\sample Create under directory my_app Folder .( Remember the name of the folder and use it later )

To write HelloWorld

In the my_app Under the folder , To write hello_world.c（ Remember to use ） file , There is no need to create src Folder .

#include <stdio.h>
// Imported this h The file comes with the project , The interior defines APP_FEATURE_INIT
#include "ohos_init.h"

void HelloWorld(void)
{
    
  printf("Hello World\r\n");
}

//harmony Start the recovery interface 
APP_FEATURE_INIT(HelloWorld);

To write BUILD.gn

This BUILD.gn The file name must be capitalized , Otherwise it will go wrong .
This document is placed in my_app Under the folder

// Specify the compilation result of the business module , For static library files libmyapp.a, The developer shall fill in according to the actual situation .
static_library("myapp") {
 sources=[
  // You just created ,hello_world.c  Pay attention to the name always 
  "hello_world.c"
 ]
  include_dirs=[
    // Just at hello_world.c The include file 
    //  Symbol // Represents the root path of the project 
    "//utils/native/lite/include"
  ]
}

gn File cannot be annotated , The notes here are just for convenience of explanation

Modify the module compilation build file BUILD.gn

[git clone In the directory ]bearpi-hm_nano\applications\BearPi\BearPi-HM_Nano\sample	 In the catalog BUILD.gn file 

import("//build/lite/config/component/lite_component.gni")

lite_component("app") {
    features = [
		//.......... Omit ........

        #"Zx_Developer:zx_develop_sample"  ## Not involved in building , Contribute demo structure to developers , among Zx by  Z1,Z2...Z100
        #"Z1_hi3861_uart_ylc:uart_hi3861",
        #"Z2_hi3861_flash_ylc:flash_example",
        // Add this line of command at the end ,my_app It was created in the beginning my_app file ,myapp It was just in BUILD.gn As defined in static_library After the name .
        "my_app:myapp",
    ]
}

gn File cannot be annotated , The notes here are just for convenience of explanation
Then compile the file and burn ,
Burning or Hi3861_wifiiot_app_allinone.bin file .

After burning, you can mobaxterm see Hello World

Lighten up led The lamp

The steps are similar to the above , So it's abbreviated

1. stay sample Create under directory my_leb Folder
2. establish leb_example.c file

#include "ohos_init.h"
#include "wifiiot_gpio.h"
#include "wifiiot_gpio_ex.h"

void led_example(void)
{
    
  GpioInit();
  IoSetFunc(WIFI_IOT_IO_NAME_GPIO_2, WIFI_IOT_IO_FUNC_GPIO_2_GPIO);
  GpioSetDir(WIFI_IOT_IO_NAME_GPIO_2, WIFI_IOT_GPIO_DIR_OUT);

  GpioSetOutputVal(WIFI_IOT_IO_NAME_GPIO_2, 1);
}
APP_FEATURE_INIT(led_example);

3. stay my_leb Create BUILD.gn file

static_library("myleb") {
 sources=[
  "led_example.c"
 ]
  include_dirs=[
    "//utils/native/lite/include",
    // Store here wifiiot_gpio.h and wifiiot_gpio_ex.h
    "//base/iot_hardware/interfaces/kits/wifiiot_lite"
  ]
}

gn File cannot be annotated , The notes here are just for convenience of explanation
4. Modify the module to compile the build file BUILD.gn
stay features Add... In the last line

"my_leb:myleb"

Notice the comma in front , Separate from the previous line .

5. Bake and record to the development board
   success ,led The light will flash continuously
6. modify led_example.c When adding led Code for flashing light

#include <stdio.h>
#include <unistd.h>
#include "ohos_init.h"
#include "wifiiot_gpio.h"
#include "wifiiot_gpio_ex.h"

void led_example(void)
{
    
  GpioInit();
  IoSetFunc(WIFI_IOT_IO_NAME_GPIO_2, WIFI_IOT_IO_FUNC_GPIO_2_GPIO);
  GpioSetDir(WIFI_IOT_IO_NAME_GPIO_2, WIFI_IOT_GPIO_DIR_OUT);

  // control led The flicker of the lamp 
  for (int i = 0; i < 10; i++)
  {
    
    // Set up WIFI_IOT_IO_NAME_GPIO_2,1 Indicates that the light is on 
    GpioSetOutputVal(WIFI_IOT_IO_NAME_GPIO_2, 1);
    usleep(1000000);
    // 0 It means that the light is off 
    GpioSetOutputVal(WIFI_IOT_IO_NAME_GPIO_2, 0);
    usleep(1000000);
  }
  GpioSetOutputVal(WIFI_IOT_IO_NAME_GPIO_2, 1);
}
APP_FEATURE_INIT(led_example);

7. Burn code
   After success led The light flashes slowly 10 Time

openharmony Introduction to compilation and construction

ninja It's a ratio. Makefile More efficient compilation and construction tools .Google Development .
When we run on the command line python build.py BearPi-HM_Nano On command ,ninja It's activated
This BearPi-HM_Nano Actually, it comes from the project directory list/product/ Under folder BearPi-HM_Nano.json