【交叉编译踩坑指北（二）】windows10下VScode构建树莓派pico开发环境（C/C++）_树莓派交叉编译用vs编写

写在前面

  许多树莓派C/C++开发都依靠NMake以及PicoProjectGenerator，安装配置NMake较为麻烦。需要安装VisualStudio 生成工具，并且安装文件夹下有很多版本的nmake需要筛选，暂时没有解决。因此本章主要使用windows中常用编译C/C++的mingw工具链（包括了mingw下的gcc,make以及gdb等），包括MinGW Makefiles来进行树莓拍Pico C/C++开发。这也沿袭了第一章中的mingw使用，具有一致性。

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本章所使用的工具和文件

以上工具和文件安装的具体路径可以参考章末视频，其中pico-sdk和pico-examples使用git可能因为会和github有连接问题，可以直接去github上下载（网址见下）。

https://www.raspberrypi.com/documentation/microcontrollers/c_sdk.html#raspberry-pi-pico-cc-sdk

github下载链接

  
  
  
pico-sdk参考文档：

注意！：安装时即使选择交叉编译器将其自动加入环境变量还是不会加入，因此需要手动加入一下。其中arm-none-eabi-gcc好像不能像gcc那样直接单用，会出现一系列路径报错（win和linux都是这样），需要结合cmake可以正常使用。

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配置CMake Tools扩展

参考第一章5.4小节配置方法

设置PICO_SDK_PATH的值为下载下来的pico-sdk位置，这两个Environment都如此设置


  
  
  
设置Generator为MinGW Makefiles（这样会使用MinGW下的make工具）

  
  
  
配置MinGW的bin目录

至此配置完毕

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点灯程序文件创建

新建本工程文件夹pico_project

在VScode中打开，并在其中新建code文件夹，CMakelists和pico_sdk_import.cmake文件，如下图

其中，pico_sdk_import.cmake是从pico_example文件中复制的，作用是cmake的时候将pico_sdk文件加进来，和前述PICO_SDK_PATH共同起作用。
pico_sdk_import.cmake

# This is a copy of <PICO_SDK_PATH>/external/pico_sdk_import.cmake

# This can be dropped into an external project to help locate this SDK
# It should be include()ed prior to project()

if (DEFINED ENV{PICO_SDK_PATH} AND (NOT PICO_SDK_PATH))
    set(PICO_SDK_PATH $ENV{PICO_SDK_PATH})
    message("Using PICO_SDK_PATH from environment ('${PICO_SDK_PATH}')")
endif ()

if (DEFINED ENV{PICO_SDK_FETCH_FROM_GIT} AND (NOT PICO_SDK_FETCH_FROM_GIT))
    set(PICO_SDK_FETCH_FROM_GIT $ENV{PICO_SDK_FETCH_FROM_GIT})
    message("Using PICO_SDK_FETCH_FROM_GIT from environment ('${PICO_SDK_FETCH_FROM_GIT}')")
endif ()

if (DEFINED ENV{PICO_SDK_FETCH_FROM_GIT_PATH} AND (NOT PICO_SDK_FETCH_FROM_GIT_PATH))
    set(PICO_SDK_FETCH_FROM_GIT_PATH $ENV{PICO_SDK_FETCH_FROM_GIT_PATH})
    message("Using PICO_SDK_FETCH_FROM_GIT_PATH from environment ('${PICO_SDK_FETCH_FROM_GIT_PATH}')")
endif ()

set(PICO_SDK_PATH "${PICO_SDK_PATH}" CACHE PATH "Path to the Raspberry Pi Pico SDK")
set(PICO_SDK_FETCH_FROM_GIT "${PICO_SDK_FETCH_FROM_GIT}" CACHE BOOL "Set to ON to fetch copy of SDK from git if not otherwise locatable")
set(PICO_SDK_FETCH_FROM_GIT_PATH "${PICO_SDK_FETCH_FROM_GIT_PATH}" CACHE FILEPATH "location to download SDK")

if (NOT PICO_SDK_PATH)
    if (PICO_SDK_FETCH_FROM_GIT)
        include(FetchContent)
        set(FETCHCONTENT_BASE_DIR_SAVE ${FETCHCONTENT_BASE_DIR})
        if (PICO_SDK_FETCH_FROM_GIT_PATH)
            get_filename_component(FETCHCONTENT_BASE_DIR "${PICO_SDK_FETCH_FROM_GIT_PATH}" REALPATH BASE_DIR "${CMAKE_SOURCE_DIR}")
        endif ()
        # GIT_SUBMODULES_RECURSE was added in 3.17
        if (${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.17.0")
            FetchContent_Declare(
                    pico_sdk
                    GIT_REPOSITORY https://github.com/raspberrypi/pico-sdk
                    GIT_TAG master
                    GIT_SUBMODULES_RECURSE FALSE
            )
        else ()
            FetchContent_Declare(
                    pico_sdk
                    GIT_REPOSITORY https://github.com/raspberrypi/pico-sdk
                    GIT_TAG master
            )
        endif ()

        if (NOT pico_sdk)
            message("Downloading Raspberry Pi Pico SDK")
            FetchContent_Populate(pico_sdk)
            set(PICO_SDK_PATH ${pico_sdk_SOURCE_DIR})
        endif ()
        set(FETCHCONTENT_BASE_DIR ${FETCHCONTENT_BASE_DIR_SAVE})
    else ()
        message(FATAL_ERROR
                "SDK location was not specified. Please set PICO_SDK_PATH or set PICO_SDK_FETCH_FROM_GIT to on to fetch from git."
                )
    endif ()
endif ()

get_filename_component(PICO_SDK_PATH "${PICO_SDK_PATH}" REALPATH BASE_DIR "${CMAKE_BINARY_DIR}")
if (NOT EXISTS ${PICO_SDK_PATH})
    message(FATAL_ERROR "Directory '${PICO_SDK_PATH}' not found")
endif ()

set(PICO_SDK_INIT_CMAKE_FILE ${PICO_SDK_PATH}/pico_sdk_init.cmake)
if (NOT EXISTS ${PICO_SDK_INIT_CMAKE_FILE})
    message(FATAL_ERROR "Directory '${PICO_SDK_PATH}' does not appear to contain the Raspberry Pi Pico SDK")
endif ()

set(PICO_SDK_PATH ${PICO_SDK_PATH} CACHE PATH "Path to the Raspberry Pi Pico SDK" FORCE)

include(${PICO_SDK_INIT_CMAKE_FILE})

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CMakeLists 这是最外层那个CmakeLists

cmake_minimum_required(VERSION 3.12)

# Pull in SDK (must be before project)
include(pico_sdk_import.cmake)

project(pico_examples C CXX ASM)
set(CMAKE_C_STANDARD 11)
set(CMAKE_CXX_STANDARD 17)
##add following sentences
pico_sdk_init()

add_subdirectory(code)

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创建好以上两个文件并修改内容之后，保存，我们进入code文件夹。在code下面创建如下文件，分别是Blink.cpp和CMakeLists.txt，其内容见下。

Blink.cpp

#include "pico/stdlib.h"
int main(){

    gpio_init(25);
    gpio_set_dir(25,GPIO_OUT);
    while(1){
        gpio_put(25,1);
        sleep_ms(1000);
        gpio_put(25,0);        
        sleep_ms(1000);
    }
    return 1;
}
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CMakeLists 这是内层那个CmakeLists，由外层所索引

add_executable(code Blink.cpp)
target_link_libraries(code pico_stdlib)
pico_add_extra_outputs(code)
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至此文件创建完毕

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程序交叉编译并生成结果

可以像第一章5.5小节那样，使用cmake quick start和cmake configure指令
而本次使用另一种方法，点击左侧cmake插件，再点击配置所有文件按钮，这时会自动生成build文件夹，当然记得选择编译器为我们之前下载的交叉编译器arm-none-eabi-gcc
  
  
  
配置所有文件

  
  
  
确认没有问题之后，进行build，同样有两种方法

或者

上传文件到pico并运行

选择uf2文件

树莓派pico接入电脑
直接把uf2拖到树莓派硬盘中
发现树莓派pico进行亮灯

当然，到这里还没完
我们上传的uf2是固件，树莓派烧录完固件后自动弹出，然后再也找不到树莓派的盘了，想要更换uf2文件怎么办？
开发手册上有说：重新烧录的方法是按住BOOTSEL的同时插上USB，这时就会回到U盘模式，可以为其重新烧录uf2文件

完美结束！

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预告：下一章是在linux上尝试树莓派开发

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本文参考

https://www.youtube.com/watch?v=BAoTBg8MJJ4

特别鸣谢！