This chapter is from the book
This chapter is from the book
This chapter is from the book
This chapter is from the book
Wireless Doorbell Code
Upload the following code to your Arduinos. If you’re having difficulty figuring out how to upload your sketches, see Chapter 5 to learn how. As before, you can download the code from https://github.com/n1/Arduino-For-Beginners.
Button Unit Code
The Button Unit sketch consists of a loop that waits for the button to be pressed, then transmits a wireless alert.
#include <Wire.h>
const int buttonPin = 8;
int buttonState = 0;
void setup()
{
Serial.begin(9600);
pinMode(buttonPin, INPUT_PULLUP);
}
void loop() {
if (Serial.available() >= 2)
{
char start = Serial.read();
if (start != '*')
{
return;
}
char cmd = Serial.read();
}
buttonState = digitalRead(buttonPin);
if (buttonState == HIGH) {
Serial.write('*');
Serial.write(1);
}
else {
Serial.write('*');
Serial.write(0);
}
delay(50); //limit how fast we update
}
Buzzer Unit Code
The Buzzer Unit code is similarly plain. The loop monitors serial traffic, then sounds the buzzer when it detects the command from the Button Unit.
#include <Wire.h>
const int buzzerPin = 13;
void setup()
{
Serial.begin(9600);
pinMode(buzzerPin, OUTPUT);
}
void process_incoming_command(char cmd)
{
int speed = 0;
switch (cmd)
{
case 1:
digitalWrite(buzzerPin, LOW);
break;
case 0:
digitalWrite(buzzerPin, HIGH);
break;
}
}
void loop() {
if (Serial.available() >= 2)
{
char start = Serial.read();
if (start != '*')
{
return;
}
char cmd = Serial.read();
process_incoming_command(cmd);
}
delay(50); //limit how fast we update
}