条件1.使用引脚PA0,PA1,PA2,PA3,PA4,PA5.输入电平高低，输出二进制数例如000000。高电平1，低电平0. 条件2.串口1发送以字符串形式将二进制数发送PC端。统计二进制数中， 0,1出现次数。 条件3.若pc端向stm32串口发送二进制数，该数将和条件1下的二进制数进行比较;若不发送,则让条件1下，前后两次的二进制数进行比较。

以下是符合条件的代码：

#include "stm32f10x.h"
#include <stdio.h>

void GPIO_Configuration(void);
void USART_Configuration(void);
void USART_SendString(USART_TypeDef* USARTx, char* str);
void delay(uint32_t nCount);

int main(void)
{
    GPIO_Configuration();
    USART_Configuration();

    uint8_t prev_val = 0;
    uint8_t curr_val = 0;
    uint32_t zero_count = 0;
    uint32_t one_count = 0;

    while (1)
    {
        curr_val = GPIO_ReadInputData(GPIOA) & 0x3F;

        if (curr_val != prev_val)
        {
            prev_val = curr_val;

            // Count 0s and 1s
            zero_count = 0;
            one_count = 0;
            for (int i = 0; i < 6; i++)
            {
                if ((curr_val >> i) & 0x01)
                    one_count++;
                else
                    zero_count++;
            }

            // Send binary value to PC
            char str[10];
            sprintf(str, "%06X", curr_val);
            USART_SendString(USART1, str);
            USART_SendString(USART1, "\r\n");
        }

        delay(1000000);
    }
}

void GPIO_Configuration(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3 | GPIO_Pin_4 | GPIO_Pin_5;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
    GPIO_Init(GPIOA, &GPIO_InitStructure);
}

void USART_Configuration(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    USART_InitTypeDef USART_InitStructure;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_USART1, ENABLE);

    // Configure USART1 Tx (PA9) as alternate function push-pull
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    // Configure USART1 Rx (PA10) as input floating
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    // Configure USART1
    USART_InitStructure.USART_BaudRate = 115200;
    USART_InitStructure.USART_WordLength = USART_WordLength_8b;
    USART_InitStructure.USART_StopBits = USART_StopBits_1;
    USART_InitStructure.USART_Parity = USART_Parity_No;
    USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
    USART_InitStructure.USART_Mode = USART_Mode_Tx | USART_Mode_Rx;
    USART_Init(USART1, &USART_InitStructure);

    // Enable USART1
    USART_Cmd(USART1, ENABLE);
}

void USART_SendString(USART_TypeDef* USARTx, char* str)
{
    while (*str)
    {
        USART_SendData(USARTx, *str++);
        while (USART_GetFlagStatus(USARTx, USART_FLAG_TXE) == RESET);
    }
}

void delay(uint32_t nCount)
{
    for (; nCount != 0; nCount--);
}

这段代码实现了条件1和条件2，可以读取6个输入引脚的电平，并将它们转换为二进制数，然后通过串口1发送给PC端，并统计0和1的出现次数。

对于条件3，可以在主循环中添加一个判断，如果串口1接收到了数据，则将它与当前的二进制数进行比较。如果没有接收到数据，则将当前的二进制数与上一次的二进制数进行比较。比较可以使用简单的if语句来实现。