main.cpp

00001 #include "mbed.h"
00002 #include "TextLCD.h"
00003 
00004 PinName pin_PSD = PC_1;
00005 
00006 AnalogIn adc_PSD(pin_PSD);
00007 
00008 // rs, rw, e, d0-d3
00009 TextLCD lcd(PB_12, PB_13, PB_14, PB_15, PA_9, PA_10, PA_11); 
00010 
00011 uint8_t Dist_cm(float volt);
00012 
00013 int main() {
00014 
00015     uint8_t dist;
00016     lcd.printf("  PSD  Program\n");
00017     lcd.printf(" Dist :     [cm]"); 
00018     while(1) {
00019         dist = Dist_cm(adc_PSD.read() * 3.3);
00020         lcd.locate(10, 1);
00021         lcd.printf("%2d", dist);
00022         wait(0.5);
00023     }
00024 }
00025 
00026 uint8_t Dist_cm(float volt)
00027 {
00028 //    float dist = 1.0/(0.0875 * volt - 0.00658);
00029     uint8_t result = 0;
00030     float dist = 1.0/(0.093 * volt - 0.009);
00031     if(dist < 0)
00032         result = 30;
00033     else
00034         result = dist;
00035     
00036     if(result < 4)
00037         result = 4;
00038     else if(result > 30)
00039         result = 30;
00040     return result;
00041 }