Example code for arduino data pump

Kart_timing_data_pump.ino

/*
  Kart_timing_data_pump
  Writes out fake kart timing data over the serial port.
  
  Copyright 2013 Andrew Schofield
*/

// The minimum and maximum lap times that can be generated 
int const MIN_LAP_TIME = 3;
int const MAX_LAP_TIME = 5;

// The number of karts to simulate
int const KART_COUNT = 5;

// Timing variables necessary to generate data for each kart without using threads
unsigned long previousMillis[KART_COUNT];
unsigned long intervalMillis[KART_COUNT];

// The time since the arduino was last reset
unsigned long currentMillis = 0;

// Configure everything
void setup() {
  Serial.begin(9600);
  for( int i = 0; i < KART_COUNT; i++) {
    previousMillis[i] = 0;
    intervalMillis[i] = 0;
  }
}

void loop() {
  currentMillis = millis();
  
  for( int i = 0; i < KART_COUNT; i++) {
    if(currentMillis - previousMillis[i] > intervalMillis[i]) {
      printKartData(i);
      previousMillis[i] = currentMillis;
      intervalMillis[i] = newLapTime();
    }
  }
}

// Assemble the output string sent over the serial port
void printKartData(int kartID) {
  char outputLine[20];
  char time[11];
  char kart[3];
    
  sprintf(time, "%010lu", millis());
  sprintf(kart, "%02x", kartID);
  strcat(outputLine, kart);
  strcat(outputLine, ":");
  strcat(outputLine, time);
  strcat(outputLine, ":");
  strcat(outputLine, "25");
  
  Serial.println(outputLine);
}

// Generate a new lap time
unsigned long newLapTime() {
  return random(MIN_LAP_TIME * 1000,MAX_LAP_TIME * 1000);
}