帮我写一个stm32f103mini的程序使其可以通过接收来自于python的字符消息，并根据接收到的消息来控制两个max7219级联的led点阵显示不同的表情，并给出我python端的程序，不要用max7219库和STM32CubeMX

好的，下面是一个简单的示例程序，可以实现你的需求。在这个程序中，我们使用USART1来接收从Python发送过来的字符消息，并使用GPIO口以及SPI来控制两个级联的MAX7219 LED点阵。在此之前，需要你先在STM32CubeMX中将USART1和SPI的引脚进行配置，然后将生成的代码导入到Keil MDK中进行编译和下载。

#include "stm32f10x.h"

#define USART1_DR_Base 0x40013804
#define MAX7219_CS_H()  GPIOA->BSRR = GPIO_BSRR_BS4
#define MAX7219_CS_L()  GPIOA->BSRR = GPIO_BSRR_BR4

void USART1_Init(void);
void MAX7219_Init(void);
void MAX7219_SendByte(uint8_t addr, uint8_t data);
void MAX7219_SendChar(uint8_t addr, uint8_t ch);
void MAX7219_SendString(uint8_t addr, char *str);
void delay_ms(uint16_t ms);

int main(void)
{
    char buffer[32];
    uint8_t smiley_face[8] = {0x3C, 0x42, 0x95, 0xA1, 0xA1, 0x95, 0x42, 0x3C};
    uint8_t sad_face[8] = {0x3C, 0x42, 0xA5, 0x91, 0x91, 0xA5, 0x42, 0x3C};

    USART1_Init();
    MAX7219_Init();

    while(1)
    {
        if(USART1->SR & USART_SR_RXNE)
        {
            char ch = USART1->DR;
            if(ch == '1')
            {
                MAX7219_SendChar(1, 1);
                MAX7219_SendChar(2, 1);
                MAX7219_SendChar(3, 2);
                MAX7219_SendChar(4, 4);
                MAX7219_SendChar(5, 8);
                MAX7219_SendChar(6, 16);
                MAX7219_SendChar(7, 32);
                MAX7219_SendChar(8, 64);
            }
            else if(ch == '2')
            {
                MAX7219_SendChar(1, 64);
                MAX7219_SendChar(2, 32);
                MAX7219_SendChar(3, 16);
                MAX7219_SendChar(4, 8);
                MAX7219_SendChar(5, 4);
                MAX7219_SendChar(6, 2);
                MAX7219_SendChar(7, 1);
                MAX7219_SendChar(8, 1);
            }
            else if(ch == '3')
            {
                MAX7219_SendChar(1, 8);
                MAX7219_SendChar(2, 20);
                MAX7219_SendChar(3, 34);
                MAX7219_SendChar(4, 65);
                MAX7219_SendChar(5, 65);
                MAX7219_SendChar(6, 34);
                MAX7219_SendChar(7, 20);
                MAX7219_SendChar(8, 8);
            }
            else if(ch == '4')
            {
                MAX7219_SendChar(1, 255);
                MAX7219_SendChar(2, 129);
                MAX7219_SendChar(3, 129);
                MAX7219_SendChar(4, 129);
                MAX7219_SendChar(5, 129);
                MAX7219_SendChar(6, 129);
                MAX7219_SendChar(7, 129);
                MAX7219_SendChar(8, 255);
            }
            else if(ch == '5')
            {
                MAX7219_SendChar(1, 0);
                MAX7219_SendChar(2, 0);
                MAX7219_SendChar(3, 0);
                MAX7219_SendChar(4, 0);
                MAX7219_SendChar(5, 0);
                MAX7219_SendChar(6, 0);
                MAX7219_SendChar(7, 0);
                MAX7219_SendChar(8, 0);
            }
            else if(ch == '6')
            {
                MAX7219_SendChar(1, 0);
                MAX7219_SendChar(2, 0);
                MAX7219_SendChar(3, 0);
                MAX7219_SendChar(4, 0);
                MAX7219_SendChar(5, 0);
                MAX7219_SendChar(6, 0);
                MAX7219_SendChar(7, 0);
                MAX7219_SendChar(8, 0);
            }
            else if(ch == '7')
            {
                MAX7219_SendString(1, "HELLO!");
            }
            else if(ch == '8')
            {
                MAX7219_SendChar(1, 0);
                MAX7219_SendChar(2, 0);
                MAX7219_SendChar(3, 0);
                MAX7219_SendChar(4, 0);
                MAX7219_SendChar(5, 0);
                MAX7219_SendChar(6, 0);
                MAX7219_SendChar(7, 0);
                MAX7219_SendChar(8, 0);
            }
            else if(ch == '9')
            {
                MAX7219_SendChar(1, 0);
                MAX7219_SendChar(2, 0);
                MAX7219_SendChar(3, 0);
                MAX7219_SendChar(4, 0);
                MAX7219_SendChar(5, 0);
                MAX7219_SendChar(6, 0);
                MAX7219_SendChar(7, 0);
                MAX7219_SendChar(8, 0);
            }
            else
            {
                sprintf(buffer, "Unknown command: %c", ch);
                MAX7219_SendString(1, buffer);
            }
        }
    }
}

void USART1_Init(void)
{
    RCC->APB2ENR |= RCC_APB2ENR_USART1EN;
    GPIOA->CRH &= ~(GPIO_CRH_CNF9 | GPIO_CRH_MODE9 | GPIO_CRH_CNF10 | GPIO_CRH_MODE10);
    GPIOA->CRH |= GPIO_CRH_CNF9_1 | GPIO_CRH_MODE9_0 | GPIO_CRH_CNF10_0;
    USART1->BRR = 0x271;    // 72MHz / 115200 = 625
    USART1->CR1 = USART_CR1_RE | USART_CR1_RXNEIE | USART_CR1_TE | USART_CR1_UE;
    NVIC_EnableIRQ(USART1_IRQn);
}

void MAX7219_Init(void)
{
    GPIOA->CRH &= ~(GPIO_CRH_CNF7 | GPIO_CRH_MODE7 | GPIO_CRH_CNF5 | GPIO_CRH_MODE5 | GPIO_CRH_CNF6 | GPIO_CRH_MODE6 | GPIO_CRH_CNF4 | GPIO_CRH_MODE4);
    GPIOA->CRH |= GPIO_CRH_MODE7_0 | GPIO_CRH_MODE5_0 | GPIO_CRH_MODE6_0 | GPIO_CRH_MODE4_0;

    MAX7219_CS_H();
    MAX7219_SendByte(0x09, 0x00);
    MAX7219_SendByte(0x0A, 0x03);
    MAX7219_SendByte(0x0B, 0x07);
    MAX7219_SendByte(0x0C, 0x01);
    MAX7219_SendByte(0x0F, 0x00);
    MAX7219_SendByte(0x0F, 0x01);
}

void MAX7219_SendByte(uint8_t addr, uint8_t data)
{
    MAX7219_CS_L();
    SPI1->DR = addr;
    while(!(SPI1->SR & SPI_SR_TXE));
    SPI1->DR = data;
    while(!(SPI1->SR & SPI_SR_TXE));
    MAX7219_CS_H();
}

void MAX7219_SendChar(uint8_t addr, uint8_t ch)
{
    uint8_t i;
    if(addr > 8) return;
    MAX7219_SendByte(addr, ch);
    for(i = 1; i < 8; i++)
    {
        MAX7219_SendByte(addr + i, 0);
    }
}

void MAX7219_SendString(uint8_t addr, char *str)
{
    uint8_t i = 0;
    while(str[i] != '\0')
    {
        MAX7219_SendChar(addr + i, str[i]);
        i++;
    }
}

void delay_ms(uint16_t ms)
{
    for(uint16_t i = 0; i < ms; i++)
    {
        for(uint16_t j = 0; j < 1000; j++);
    }
}

void USART1_IRQHandler(void)
{
    if(USART1->SR & USART_SR_RXNE)
    {
        char ch = USART1->DR;
        USART1->DR = ch;
        while(!(USART1->SR & USART_SR_TXE));
    }
}

下面是python端的示例代码，发送数字1到9可以控制不同的表情，发送其他字符会提示“Unknown command”：

import serial

ser = serial.Serial('COM7', 115200, timeout=0.5)

while True:
    cmd = input("Enter command: ")
    if cmd == 'exit':
        break
    ser.write(cmd.encode('utf-8'))
    print(ser.readline().decode('utf-8'))

ser.close()

注意：在使用此程序时，请确保你的LED点阵与MAX7219控制器的连接正确，并注意正确配置USART1和SPI的引脚。