Page 112 - Programming the Photon Getting Started With the Internet of Things

Schematic Reference Description Appendix

M1 Photon board M1

400-point breadboard H1

R4 Photocell (200 K) R4

R5 Resistor (10 K) R3

Jumper wires H2

D1 RGB LED S3

R1, 2, 3 220-ohm resistor R1

Table 5.2 Components and Equipment

Here is the sketch for reading the light levels from a photocell:

int red = D0;
int green = D2;
int blue = D1;

void setup() {
pinMode(red, OUTPUT);
pinMode(green, OUTPUT);

pinMode(blue, OUTPUT);

}

void loop() {
int value = analogRead(A0);

int percentage = map(value, 0, 4095, 0, 100);

if (percentage < 33) {
digitalWrite(green, HIGH);
digitalWrite(red, LOW);
digitalWrite(blue, LOW);

}
else if (percentage > 33 & < 66) {
digitalWrite(green, LOW);
digitalWrite(red, LOW);

digitalWrite(blue, HIGH);