pico的micropython使用

工具：Thonny, Python IDE for beginners
设置解释器为micro python （pico）, 选择好串口，按住按键插入usb，电脑会多出来一个盘

之后把rp2-pico-20210418-v1.15.uf2复制进去，自动重启后连接上。
此时thonny内输入代码：

import machine
import utime
led_onboard = machine.Pin(25, machine.Pin.OUT)
while True:
        led_onboard.value(1)
        utime.sleep_ms(1000)
        led_onboard.value(0)
        utime.sleep_ms(1000)

点击运行当前脚本,板子上的灯就会闪烁了。

由于在公司做的项目都是和freeRTOS有关，而且看到这个RPI-pico是Arm Cortex-M0 +的，是不是也可以在RPI-pico上运行起轻量操作系统呢？答案是肯定的👇

pico跑freeRTOS

出于好奇搜了一下，果然有有意思的项目：
Raspberry Pi Pico Gets supports for Rust, RT-Thread OS and FreeRTOS
上面这个链接中提到了有人在用pico树莓派跑freeRTOS
PicoCPP/RPI-pico-FreeRTOS (github.com)

虽然这个项目只有60个star，但是被网站引用了，看来是可行的

搞起来！

下载代码

git clone --recursive git@github.com:PicoCPP/RPI-pico-FreeRTOS.git

看一下代码。main.cpp中进行了task创建并开启调度，他创建了这一个task：

static pico_cpp::GPIO_Pin ledPin(25,pico_cpp::PinType::Output);
void vTaskCode( void * pvParameters )
{
    /* The parameter value is expected to be 1 as 1 is passed in the
    pvParameters value in the call to xTaskCreate() below. 
    configASSERT( ( ( uint32_t ) pvParameters ) == 1 );
    */
    for( ;; )
    {
            ledPin.set_high();
            vTaskDelay(1000);
            ledPin.set_low();
            vTaskDelay(1000);
    }
}

环境：
cmake ：我用的cmake-3.21.0-windows-x86_64.msi，最好版本>3.12
GNU Arm Embedded Toolchain：我用的10 2020-q4-major
python：python3的环境即可，我是python3.7.9
把上面两个工具的bin文件目录加到系统path中，python目录也加入path内

由于我安装了Visual Studio，已经有MSVC环境，在Windows上，默认情况下，CMake生成MSVC解决方案。所以要在cmake时指定使用的是Unix平台，这样可以生成Makefile。即使用-G"Unix Makefiles"(如果没有装Visual Studio的话不用加)
输入下面命令：

$ mkdir build
$ cd build
$ cmake .. -G"Unix Makefiles"

可以打印出以下log，表示cmake完成：

D:\work\pico\RPI-pico-FreeRTOS>mkdir build

D:\work\pico\RPI-pico-FreeRTOS>cd build

D:\work\pico\RPI-pico-FreeRTOS\build>cmake .. -G"Unix Makefiles"
PICO_SDK_PATH is D:/work/pico/RPI-pico-FreeRTOS/pico-sdk
Defaulting PICO_PLATFORM to rp2040 since not specified.
Defaulting PICO platform compiler to pico_arm_gcc since not specified.
-- Defaulting build type to 'Release' since not specified.
PICO compiler is pico_arm_gcc
-- The C compiler identification is GNU 10.2.1
-- The CXX compiler identification is GNU 10.2.1
-- The ASM compiler identification is GNU
-- Found assembler: C:/Program Files (x86)/GNU Arm Embedded Toolchain/10 2020-q4-major/bin/arm-none-eabi-gcc.exe
Defaulting PICO target board to pico since not specified.
Using board configuration from D:/work/pico/RPI-pico-FreeRTOS/pico-sdk/src/boards/include/boards/pico.h
-- Found Python3: C:/python37/python.exe (found version "3.7.9") found components: Interpreter
TinyUSB available at D:/work/pico/RPI-pico-FreeRTOS/pico-sdk/lib/tinyusb/src/portable/raspberrypi/rp2040; adding USB support.
-- Configuring done
-- Generating done
-- Build files have been written to: D:/work/pico/RPI-pico-FreeRTOS/build

D:\work\pico\RPI-pico-FreeRTOS\build>

再输入

$ make

打印出以下log(已省略)，编译完成，并且编译出来的elf文件已经转换成uf2格式文件：

D:\work\pico\RPI-pico-FreeRTOS\build>make
Scanning dependencies of target bs2_default
[  1%] Building ASM object pico-sdk/src/rp2_common/boot_stage2/CMakeFiles/bs2_default.dir/compile_time_choice.S.obj
[  2%] Linking ASM executable bs2_default.elf
[  2%] Built target bs2_default
。
。
。
[ 98%] Building C object CMakeFiles/hello_world.dir/pico-sdk/src/rp2_common/pico_stdio_uart/stdio_uart.c.obj
[100%] Linking CXX executable hello_world.elf
   text    data     bss     dec     hex filename
  19480      28   52832   72340   11a94 hello_world.elf
[100%] Built target hello_world

D:\work\pico\RPI-pico-FreeRTOS\build>