Spectrophotometer code to use in Arduino
const int redPin = 3;
const int greenPin = 5;
const int bluePin = 6;
const int ldrPin = A0;
void setup() {
Serial.begin(9600);
}
void loop() {
int wavelength = 380; // Start at 380nm
while (wavelength <= 780) { // Scan up to 780nm
// Convert wavelength to RGB values
int redValue = getRGBValue(wavelength, 'R');
int greenValue = getRGBValue(wavelength, 'G');
int blueValue = getRGBValue(wavelength, 'B');
// Set RGB LED values
analogWrite(redPin, redValue);
analogWrite(greenPin, greenValue);
analogWrite(bluePin, blueValue);
// Read LDR sensor value and print to serial monitor
int ldrValue = analogRead(ldrPin);
Serial.print("Wavelength: ");
Serial.print(wavelength);
Serial.print("nm, LDR Value: ");
Serial.println(ldrValue);
wavelength++; // Increment wavelength
delay(100); // Delay for stability
}
}
// Convert wavelength to RGB values
int getRGBValue(int wavelength, char color) {
double gamma = 0.8;
double factor = 0.1;
double R, G, B;
if (wavelength < 380 || wavelength > 780) {
return 0;
}
if (wavelength >= 380 && wavelength < 440) {
R = -(wavelength - 440) / (440 - 380);
G = 0;
B = 1;
} else if (wavelength >= 440 && wavelength < 490) {
R = 0;
G = (wavelength - 440) / (490 - 440);
B = 1;
} else if (wavelength >= 490 && wavelength < 510) {
R = 0;
G = 1;
B = -(wavelength - 510) / (510 - 490);
} else if (wavelength >= 510 && wavelength < 580) {
R = (wavelength - 510) / (580 - 510);
G = 1;
B = 0;
} else if (wavelength >= 580 && wavelength < 645) {
R = 1;
G = -(wavelength - 645) / (645 - 580);
B = 0.0;
} else if (wavelength >= 645 && wavelength < 781) {
R = 1;
G = 0;
B = 0;
}
if (color == 'R') {
return 255 * pow(R, gamma);
} else if (color == 'G') {
return 255 * pow(G, gamma);
} else if (color == 'B') {
return 255 * pow(B, gamma);
}
}