一、赛题分析
模拟液位检测告警系统，涉及到KEY、ADC、EEPROM、LED、USART、LCD等模块。本届赛题相对简单，各个模块均可在往期文章中找到配置方法和编写说明。如：
蓝桥杯嵌入式——第六届省赛“电压测量监控设备”旧版标准库_对愁眠后霜满天的博客-CSDN博客
本届赛题主要难点在于对液位上升和下降趋势的判断，并通过串口发送至电脑。以及串口查询，和存储液面阀值。
二、程序设计
本届赛题所用到的模块均在往届赛题有所涉及，具体可查看往期文章或在文章最后下载本届赛题的项目工程。
1、对液面等级变化趋势的判断
对于此处，博主的思想是：在while(1)之前要读取一次ADC采样值，判断level等级，并标记此时的液面等级。再在while(1)中level改变之前标记和改变之后的值进行对比，可得出液面变化趋势。
2、串口发送查询部分
对于此处，题目中要求对接收一个字符数据的判断。所以可以先接收数据再判断是否满足条件，若不满足查询条件直接清除，若满足则发送查询数据，再清除接收数据。如果不清除接收数据，则多次串口发送后可能会出错。
void USART2_IRQHandler(void) {if(USART_GetITStatus(USART2,USART_IT_RXNE) != RESET){USART_ClearITPendingBit(USART2,USART_IT_RXNE);USART_RXBUF[RXCUNT++] = USART_ReceiveData(USART2);if(USART_RXBUF[0] != '\0'){USART_ITConfig(USART2,USART_IT_RXNE,ENABLE);RXOVER = 1; }}}/* 此为部分，整体可在主函数中体现if(RXOVER == 1){RXOVER = 0;RXCUNT = 0;if(USART_RXBUF[0] == 'C'){memset(string,0,sizeof(string));sprintf((char*)string,"C:H%d+L%d\\r\\n\r\n",Height,leve);USART_SendString(USART2,string);led3_flag = 1;}if(USART_RXBUF[0] == 'S'){memset(string,0,sizeof(string));sprintf((char*)string,"S:TL%d+TM%d+TH%d\\r\\n\r\n",TH.th_1,TH.th_2,TH.th_3);USART_SendString(USART2,string);led3_flag = 1;}memset(USART_RXBUF,0,sizeof(USART_RXBUF));}*/
3、main.c
写I2C之后一定要延时5ms左右10ms比较保险，不然可能出错。
#include "stm32f10x.h"#include "lcd.h"#include "led.h"#include "key.h"#include "delay.h"#include "adc.h"#include "timer.h"#include "usart.h"#include "i2c.h"#include "stdio.h"#include "string.h"struct Level{u8 th_1,th_2,th_3;}TH={30,50,70};enum show_stat{Level,Setting};u8 Height = 0,leve = 0,leve_flag = 0,select_flag = 0;u8 ADC_Flag,led_flag = 0,key_flag = 0,show_flag = Level;u8 led2_flag = 0,ld2 = 0,led3_flag = 0,ld3 = 0;u8 string[20];float adc_temp;void key_in(void);void show_lcd(void);void highlight_char(u8 Line, u8 *ptr);void height_leve(void);void Leve_init(void);void judgement_usart(void);void led_state(void);//Main Bodyint main(void){STM3210B_LCD_Init();LCD_Clear(Black);LCD_SetBackColor(Black); LCD_SetTextColor(White); SysTick_Config(SystemCoreClock/1000);TIM4_Init();USART2_Init(9600);LED_Init();KEY_Init();ADC_INIT();i2c_init();TH.th_1 = i2c_read(0x32);if(TH.th_1 > 95&&TH.th_1%5 != 0)TH.th_1 = 30;TH.th_2 = i2c_read(0x33);if(TH.th_2 > 95&&TH.th_2%5 != 0)TH.th_2 = 50;TH.th_3 = i2c_read(0x34);if(TH.th_3 > 95&&TH.th_3%5 != 0)TH.th_3 = 70;Leve_init();while(1){key_in();show_lcd();led_state();}}void Leve_init(void){adc_temp = Read_ADC();Height = adc_temp * 100 / 3.3;height_leve();leve_flag = leve;}void key_in(void){key_flag = key_scan();if(key_flag == 1){show_flag =! show_flag;LCD_Clear(Black);}if(key_flag == 2&&show_flag == Setting){select_flag = (select_flag + 1) % 3;}if(key_flag == 3&&show_flag == Setting){if(select_flag == 0&&TH.th_1<95)TH.th_1 = TH.th_1 + 5;if(select_flag == 1&&TH.th_2<95)TH.th_2 = TH.th_2 + 5;if(select_flag == 2&&TH.th_3<95)TH.th_3 = TH.th_3 + 5;i2c_write(0x32,TH.th_1);Delay_Ms(10);i2c_write(0x33,TH.th_2);Delay_Ms(10);i2c_write(0x34,TH.th_3);Delay_Ms(10);}if(key_flag == 4&&show_flag == Setting){if(select_flag == 0&&TH.th_1>5)TH.th_1 = TH.th_1 - 5;if(select_flag == 1&&TH.th_2>5)TH.th_2 = TH.th_2 - 5;if(select_flag == 2&&TH.th_3>5)TH.th_3 = TH.th_3 - 5;i2c_write(0x32,TH.th_1);Delay_Ms(10);i2c_write(0x33,TH.th_2);Delay_Ms(10);i2c_write(0x34,TH.th_3);Delay_Ms(10);}}void show_lcd(void){if(ADC_Flag){ADC_Flag = 0;adc_temp = Read_ADC();}if(show_flag == Level){LCD_DisplayStringLine(Line1,(u8*)" Liquid Level ");Height = adc_temp * 100 / 3.3;memset(string,0,sizeof(string));sprintf((char*)string," Height:%dcm ",Height);LCD_DisplayStringLine(Line3,string);memset(string,0,sizeof(string));sprintf((char*)string,"ADC:%.2fV ",adc_temp);LCD_DisplayStringLine(Line5,string);judgement_usart();memset(string,0,sizeof(string));sprintf((char*)string," Level:%d ",leve);LCD_DisplayStringLine(Line7,string);}else if(show_flag == Setting){LCD_DisplayStringLine(Line1,(u8*)" Parameter Setup ");memset(string,0,sizeof(string));sprintf((char*)string," Threshold1:%dcm ",TH.th_1);if(select_flag == 0)highlight_char(Line3,string);else LCD_DisplayStringLine(Line3,string);memset(string,0,sizeof(string));sprintf((char*)string," Threshold2:%dcm ",TH.th_2);if(select_flag == 1)highlight_char(Line5,string);else LCD_DisplayStringLine(Line5,string);memset(string,0,sizeof(string));sprintf((char*)string," Threshold3:%dcm ",TH.th_3);if(select_flag == 2)highlight_char(Line7,string);else LCD_DisplayStringLine(Line7,string);}}void highlight_char(u8 Line, u8 *ptr){u32 i = 0;u16 refcolumn = 319;while ((*ptr != 0) && (i < 20)) {LCD_SetTextColor(Yellow);LCD_DisplayChar(Line, refcolumn, *ptr);LCD_SetTextColor(White);refcolumn -= 16;ptr++;i++;}}void judgement_usart(void){leve_flag = leve;height_leve();if(leve_flag>leve){memset(string,0,sizeof(string));sprintf((char*)string,"A:H%d+L%d+D\\r\\n\r\n",Height,leve);USART_SendString(USART2,string);led2_flag = 1;}if(leve_flag<leve){memset(string,0,sizeof(string));sprintf((char*)string,"A:H%d+L%d+U\\r\\n\r\n",Height,leve);USART_SendString(USART2,string);led2_flag = 1;}leve_flag = leve;if(RXOVER == 1){RXOVER = 0;RXCUNT = 0;if(USART_RXBUF[0] == 'C'){memset(string,0,sizeof(string));sprintf((char*)string,"C:H%d+L%d\\r\\n\r\n",Height,leve);USART_SendString(USART2,string);led3_flag = 1;}if(USART_RXBUF[0] == 'S'){memset(string,0,sizeof(string));sprintf((char*)string,"S:TL%d+TM%d+TH%d\\r\\n\r\n",TH.th_1,TH.th_2,TH.th_3);USART_SendString(USART2,string);led3_flag = 1;}memset(USART_RXBUF,0,sizeof(USART_RXBUF));}}void height_leve(void){if(Height<=TH.th_1)leve = 0;else if(Height>TH.th_1&&Height<=TH.th_2)leve = 1;else if(Height>TH.th_2&&Height<=TH.th_3)leve = 2;else leve = 3;}void led_state(void){LED_Control(LED1,led_flag);LED_Control(LED2,ld2);LED_Control(LED3,ld3);}void TIM4_IRQHandler(void){static u16 led_cnt = 0,led2_cnt = 0,led3_cnt = 0;if (TIM_GetITStatus(TIM4,TIM_IT_Update) != RESET){TIM_ClearITPendingBit(TIM4, TIM_IT_Update);if(++led_cnt>=1000){led_cnt = 0;led_flag =! led_flag;}if(led2_flag == 1){if(++led2_cnt%200 == 0)ld2 =! ld2;if(led2_cnt>=2000){led2_cnt = 0;led2_flag = 0;ld2=0;}}if(led3_flag == 1){if(++led3_cnt%200 == 0)ld3 =! ld3;if(led3_cnt>=2000){led3_cnt = 0;led3_flag = 0;ld3=0;}}}}
三、工程附上
链接：/s/1mD5Mwb8kkYdkKlSh0Y9uhg
提取码：foao
有不对的地方，请多指教...
