Diff: main.cpp

Revision:

1:034f79c00c98

Parent:

0:b88af2ed370b

Child:

2:b47f8dbf374c

--- a/main.cpp	Tue Dec 01 13:38:46 2015 +0000
+++ b/main.cpp	Wed Sep 28 16:05:35 2016 +0000
@@ -1,66 +1,89 @@
+// Scalextric Timer for Ada Lovelace Day
+//
+// Uses Nucleo board F072 with LCD Keypad shield
+// Connect D3 to Trig & D2 to Echo
+// Connect VCC to 5V (pin CN7 18)
+// Connect GND to 0V (pin CN7 19)
+
 #include "mbed.h"
-#include "hcsr04.h"
+#include "hcsr04.h"     // Ultrasonic sensor
+#include "TextLCD.h"    // LCD1602
 
+// serial PC for debug
 Serial pc(SERIAL_TX, SERIAL_RX);
-HCSR04  usensor(D2,D4);
-DigitalOut myled1(LED1);
-Timer t;
-Timer wait_t;
+// Ultrasonic sensor
+HCSR04  usensor(D3,D2);  // Trig, Echo
+
+// LCD Shield
+TextLCD lcd(D8, D9, D4, D5, D6, D7);   // used to drive display
+AnalogIn keys(A0);                     // used to sample buttons
+
+Timer lap_timer;
+Timer wait_timer;
+
+// display text on LCD
+void textLCD(char *text, int line) {
+    char tmpBuf[16];
+    for (int i = 0; i < 16; i++) tmpBuf[i] = 0x20;
+    for (int i = 0; i < strlen(text); i++) {
+        if (i < 16) tmpBuf[i] = text[i];
+        lcd.locate(i, line);
+        lcd.putc(tmpBuf[i]);
+    }
+}
+
 
 int main()
 {
+    // Variables used
     int dist = 0;
     float current_time = 0;
-    float fastest_time = 99999;
+    int lap_count = 0;
     float wait_time = 2.0;
-    int lap_count = 0;
-    int fastest_lap = 0;
     pc.baud(9600);
-    myled1 = 1;
+    char lap_string[16];
+    char laptime_string[16];
     
-    float min_laptime = 1.0; // s
-    int num_laps = 10;
-    int sample_time = 100; //ms
+    // Values to tune
+    float min_laptime = 1.0; // Minimum laptime - time to wait after seeing car before measuring again in seconds
+    int sample_time = 100;   // Sample time - time between sampling value from sensor in milliseconds
+    int trigger_distance = 4;  // Trigger distance - distance below which the car registers as detected
 
+    // Intro Screen
     pc.printf("ARM Sheffield Scalextric Challenge \n");
- 
-    while(lap_count < num_laps+1) {
+    textLCD("ARM Scalextric ", 0);
+
+    // Main loop
+    while(1) {
        usensor.start();
        wait_ms(sample_time);
        dist=usensor.get_dist_cm();
-       //pc.printf("Distance %d\n\r", dist);
+       pc.printf("Distance %d\n\r", dist);  // Debug to Serial port/USB
        if (lap_count > 0) { 
-         wait_time = wait_t.read();
+         wait_time = wait_timer.read();
        }
-       if ((dist < 10) and (wait_time > min_laptime)) { // spotted car at least a minimum laptime later
-         myled1 = 1;
-         wait_t.reset();
-         wait_t.start();
-         if (lap_count == 0) {
-           t.reset();
-           t.start();
-           pc.printf("Timing... \r");
+       if ((dist < trigger_distance) and (wait_time > min_laptime)) { // spotted car at least a minimum laptime later
+         wait_timer.reset();
+         wait_timer.start();
+         if (lap_count == 0) {   // First Lap - start timer
+           lap_timer.reset();
+           lap_timer.start();
+           pc.printf("Timing... \r");        // Debug
+           textLCD("Timing..........", 1);   // 
            lap_count++; 
-         } else {      
-           //t.stop();
-           current_time = t.read();
-           t.reset();
-           if (current_time < fastest_time) {
-             fastest_time = current_time;
-             fastest_lap = lap_count;
-           }
-           pc.printf("Lap : %d, Lap time : %f s , Fastest Lap Time : %f s \r", lap_count, current_time, fastest_time);
+         } else {                // Completed a lap
+           current_time = lap_timer.read();
+           lap_timer.reset();
+           pc.printf("Lap : %d, Lap time : %f s \r", lap_count, current_time);
+           sprintf(lap_string, "Lap : %d ", (char*)lap_count);
+           sprintf(laptime_string, "Lap time : %f s, ", current_time);
+           textLCD("                ", 0);
+           textLCD(lap_string, 0);
+           textLCD("                ", 1);
+           textLCD(laptime_string, 1);
            lap_count++; 
         }
-       }  else { 
-          myled1 = 0;
-       } 
+      }  
     }   
-    pc.printf("\n GAME OVER \n");
-    pc.printf("Fastest Lap Time : %f s on Lap : %d \n", fastest_time, fastest_lap);
-
-    t.stop();
-    wait_t.stop();
-
 }