Datasheet

Chapter 2 • Shield, Lights, Servo Motors
54 • Robotics with the BOE Shield-Bot
/*
Robotics with the BOE Shield - HighLowLed
Turn LED connected to digital pin 13 on/off once every second.
*/
void setup() // Built-in initialization block
{
pinMode(13, OUTPUT); // Set digital pin 13 -> output
}
void loop() // Main loop auto-repeats
{
digitalWrite(13, HIGH); // Pin 13 = 5 V, LED emits light
delay(500); // ..for 0.5 seconds
digitalWrite(13, LOW); // Pin 13 = 0 V, LED no light
delay(500); // ..for 0.5 seconds
}
Introducing the Timing Diagram
A timing diagram is a graph that relates a signal's high and low stages to time. This timing
diagram shows you a 1000 ms slice of the
HIGH (5 V) and LOW (0 V) signals from the sketch
HighLowLed. Can you see how
delay(500) is controlling the blink rate?
Your Turn – Experiment with the Blink Rates and Both LEDs
How would you make the LED blink twice as fast? How about reducing the delay function’s
ms parameters by half?