main.cpp

00001 // Scalextric Timer for Ada Lovelace Day
00002 //
00003 // Uses Nucleo board F072 with LCD Keypad shield
00004 // Connect D3 to Trig & D2 to Echo
00005 // Connect VCC to 5V (pin CN7 18)
00006 // Connect GND to 0V (pin CN7 19)
00007 
00008 #include "mbed.h"
00009 #include "hcsr04.h"     // Ultrasonic sensor
00010 #include "TextLCD.h"    // LCD1602
00011 
00012 // serial PC for debug
00013 //Serial pc(SERIAL_TX, SERIAL_RX);
00014 // Ultrasonic sensor
00015 HCSR04  usensor(D3,D2);  // Trig, Echo  - locks sometimes
00016 
00017 // LCD Shield
00018 TextLCD lcd(D8, D9, D4, D5, D6, D7);   // used to drive display
00019 //AnalogIn keys(A0);                     // used to sample buttons
00020 
00021 Timer lap_timer;
00022 
00023 // Subroutine to display text on LCD - called from below
00024 // call as follows:
00025 // textLCD(text, line)
00026 // where text = up to 16 characters of text
00027 // line = line 0 or 1 on the LCD; where 0 is the top line and 1 is the bottom line
00028     
00029 void textLCD(char *text, int line) {
00030 
00031     char tmpBuf[16];    
00032     for (int i = 0; i < 14; i++) {
00033         if (i < strlen(text)) {
00034           tmpBuf[i] = text[i];
00035         } 
00036         else 
00037         {
00038             tmpBuf[i] = 0x20;
00039         }
00040         lcd.locate(i, line);
00041         lcd.putc(tmpBuf[i]);
00042     }
00043 }
00044 
00045 // Subroutine to display Lap data on LCD - called from below
00046 // call as follows:
00047 // DisplayLap(lap_count, dist, lap_time, Show_Time);
00048 
00049 void DisplayLap(int lcl_lap_count, int lcl_dist, float lcl_lap_time, bool Show_Time) {
00050 
00051     char lap_string[16];    
00052     char lap_string2[16];    
00053     //textLCD("1               ", 0);  // Clear top line on LCD
00054     //textLCD("2               ", 1);  // Clear bottom line on LCD
00055     //lcd.cls();
00056 
00057     int lcl_lap_time_integerPart = (int)lcl_lap_time;
00058     int lcl_lap_time_decimalPart = ((int)(lcl_lap_time*1000)%1000);
00059 
00060     sprintf(lap_string, "Lap : %d D : %d", (char*)lcl_lap_count, (char*)lcl_dist);      // Format Lap count string   
00061 //    pc.printf("%s \n\r", lap_string);
00062     textLCD("1               ", 0);  // Clear top line on LCD
00063     textLCD(lap_string, 0);          // Display distance on LCD
00064     
00065     if (Show_Time) {
00066         sprintf(lap_string2, "Time : %d.%d s, ", (char*)lcl_lap_time_integerPart, (char*)lcl_lap_time_decimalPart);  // Format Lap time string
00067 //        pc.printf("%s \n\r", lap_string);
00068         textLCD("1               ", 1);  // Clear bottom line on LCD
00069         textLCD(lap_string2, 1);      // Display Lap Time on LCD
00070     }
00071  }
00072         
00073 ///////////////////////////////////////////////////////////////////////////////
00074 // Main Program starts here
00075 ///////////////////////////////////////////////////////////////////////////////
00076 
00077 int main()
00078 {
00079  
00080  //// Try changing these:
00081     // Variables to tune
00082     float min_laptime = 1.0; // Minimum laptime - time to wait after seeing car before measuring again in seconds
00083     int sample_time = 500;   // Sample time - time between sampling values from sensor in milliseconds
00084     int trigger_distance = 5;  // Trigger distance - distance below which the car registers as detected
00085 //// Careful with anything after this though
00086 
00087     // Variables used within the program - set to their initial values
00088     int dist = 0;
00089     float lap_time = 0.0;
00090     int lap_count = 0;
00091 
00092     
00093     // Initialise the serial interface and set its data rate
00094  //   pc.baud(9600);
00095 
00096     // Intro Screen
00097  //   pc.printf("ARM Sheffield Scalextric Challenge \n"); // Display to Serial Interface
00098     textLCD("ARM Scalextric ", 0);  // Display on First Line of LCD
00099     wait_ms(2000);  // Wait 2s
00100     textLCD("                ", 0);  // Clear top line on LCD
00101 
00102     // Main loop - runs forever
00103     while(1) {
00104        // Set up and read ultrasonic sensor after "sample_time"
00105        usensor.start();
00106        wait_ms(sample_time);
00107        dist=usensor.get_dist_cm();  // read sesnsor distance measure 
00108        //pc.printf("Lap %d Distance %d wait_time %d \n\r", lap_count, dist, wait_time);  // Debug - display distance to Serial Interface
00109        if (dist < trigger_distance) { // Spotted something closer than trigger_distance from the sensor
00110          if (lap_count == 0) {   // First Lap - start lap timer
00111            lap_timer.reset();
00112            lap_timer.start();
00113            //pc.printf("Timing... \r");        // Debug to Serial Interface
00114            textLCD("Timing..........", 1);   // Message to LCD
00115          } else {                // Completed a lap
00116            lap_time = lap_timer.read();  // Get time for lap
00117            lap_timer.reset();
00118            DisplayLap(lap_count, dist, lap_time, 1);
00119         }
00120         lap_count++;               // Increment lap counter by 1
00121         wait(min_laptime);         // Wait for a time before starting to monitor sensor for next lap
00122       }     // end of something spotted
00123       else  // nothing spotted - output debug
00124       {   
00125         DisplayLap(lap_count, dist, lap_time, 0);
00126       }
00127     }     // end of main while loop
00128     
00129      
00130 }  // end of main program
00131