本程使用MPX4250。程序运行时，传感器向单片机输入电压信号，经A/D转换后，根据技术手册提供的公式进行，最后显示在数码管上。
Proteus仿真截图：
Atmel Studi6.2 运行截图：
程序清单：
- /*
- * GccApplication38.c
- *
- * Created: 2014-12-23 20:48:39
- * Author: Administrator
- */
- #define F_CPU 4000000UL
- #include <avr/io.h>
- #include <util/delay.h>
- #include <stdint.h>
- const uint8_t SEG_CODE[] = {0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07,0x7F,0x6F,0x00};
- uint8_t SEG_Display_Buffer[] = {0xF3,0,0,0};
-
- void Show_PRESS_ON_DSY()
- {
- uint8_t i = 0;
- for(i=0;i<4;i++)
- {
- PORTD = ~_BV(i);
- PORTC = SEG_Display_Buffer[i];
- _delay_ms(4);
- }
- }
- int main(void)
- {
- int AD_Result,Pressure_Value;
- DDRA = 0x7F; PORTA = 0xFF;
- DDRC = 0xFF; PORTC = 0xFF;
- DDRD = 0xFF; PORTD = 0xFF;
- ADCSRA = 0xe6;
- _delay_ms(2000);
- ADMUX = 0x07;
-
-
- while(1)
- {
- AD_Result = ADCL + (ADCH << 8);
- Pressure_Value = (AD_Result * 5.0/1023.0/5.1 - 0.04)/0.00369 + 1.99;
- SEG_Display_Buffer[1] = SEG_CODE[Pressure_Value/100];
- SEG_Display_Buffer[2] = SEG_CODE[Pressure_Value/10 % 10];
- SEG_Display_Buffer[3] = SEG_CODE[Pressure_Value%10];
- if(SEG_Display_Buffer[1]==0x3F)
- {
- SEG_Display_Buffer[1] = 0x00;
- if(SEG_Display_Buffer[2] == 0x3F)SEG_Display_Buffer[2] = 0x00;
- }
- Show_PRESS_ON_DSY();
- }
- }
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