Datasheet

Robot Control with Distance Detection • Chapter 8
Robotics with the BOE Shield-Bot • 253
If it turns out that the detection range of one side is twice as far as the other (or more), check
the resistors connected to the IR LEDs. You may have a mismatch there; make sure both
resistors are 2 kΩ (red-black-red). If there isn’t a mismatch, try adjusting IR LED resistor
values until the detection ranges of both sides are in the same neighborhood.
/*
* Robotics with the BOE Shield - DisplayBothDistances
* Display left and right IR states in Serial Monitor.
* Distance range is from 0 to 5. Only a small range of several cm
* in front of each detector is measureable. Most of it will be 0 (too
* close) or 5 (too far).
*/
void setup() // Built-in initialization block
{
tone(4, 3000, 1000); // Play tone for 1 second
delay(1000); // Delay to finish tone
pinMode(10, INPUT); pinMode(9, OUTPUT); // Left IR LED & Receiver
pinMode(3, INPUT); pinMode(2, OUTPUT); // Right IR LED & Receiver
Serial.begin(9600); // Set data rate to 9600 bps
}
void loop() // Main loop auto-repeats
{
int irLeft = irDistance(9, 10); // Measure left distance
int irRight = irDistance(2, 3); // Measure right distance
Serial.print(irLeft); // Display left distance
Serial.print(" "); // Display spaces
Serial.println(irRight); // Display right distance
delay(100); // 0.1 second delay
}
// IR distance measurement function
int irDistance(int irLedPin, int irReceivePin)
{
int distance = 0;
for(long f = 38000; f <= 42000; f += 1000) {
distance += irDetect(irLedPin, irReceivePin, f);
}
return distance;
}
// IR Detection function
int irDetect(int irLedPin, int irReceiverPin, long frequency)
{
tone(irLedPin, frequency, 8); // IRLED 38 kHz for at least 1 ms
delay(1); // Wait 1 ms