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refactor calctemp

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This commit is contained in:
ladyada 2025-05-13 10:25:24 -04:00
parent 761fd38a15
commit 9de432a84a
3 changed files with 27 additions and 33 deletions
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20
Adafruit_OPT4048.cpp
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@ -1020,27 +1020,19 @@ bool Adafruit_OPT4048::getCIE(double *CIEx, double *CIEy, double *lux) {
* n = (x - 0.3320) / (0.1858 - y)
* CCT = 437 * n^3 + 3601 * n^2 + 6861 * n + 5517
*
* @return The calculated color temperature in Kelvin, or 0 if calculation failed
* @param CIEx The CIE x chromaticity coordinate
* @param CIEy The CIE y chromaticity coordinate
* @return The calculated color temperature in Kelvin
*/
double Adafruit_OPT4048::getColorTemperature(void) {
if (!i2c_dev) {
return 0.0;
}
// Get CIE coordinates
double x, y, lux;
if (!getCIE(&x, &y, &lux)) {
return 0.0;
}
double Adafruit_OPT4048::calculateColorTemperature(double CIEx, double CIEy) {
// Check for invalid coordinates
if (x == 0 && y == 0) {
if (CIEx == 0 && CIEy == 0) {
return 0.0;
}
// Calculate using McCamy's formula from spreadsheet
// n = (x - 0.3320) / (0.1858 - y)
double n = (x - 0.3320) / (0.1858 - y);
double n = (CIEx - 0.3320) / (0.1858 - CIEy);
// CCT = 437 * n^3 + 3601 * n^2 + 6861 * n + 5517
double cct = (437.0 * n * n * n) + (3601.0 * n * n) + (6861.0 * n) + 5517.0;

6
Adafruit_OPT4048.h
View file

@ -181,9 +181,11 @@ public:
* Uses the McCamy's approximation formula to calculate CCT from CIE 1931 x,y coordinates.
* This is accurate for color temperatures between 2000K and 30000K.
*
* @return The calculated color temperature in Kelvin, or 0 if calculation failed
* @param CIEx The CIE x chromaticity coordinate
* @param CIEy The CIE y chromaticity coordinate
* @return The calculated color temperature in Kelvin
*/
double getColorTemperature(void);
double calculateColorTemperature(double CIEx, double CIEy);
private:
Adafruit_I2CDevice *i2c_dev;

34
examples/test_opt4048/test_opt4048.ino
View file

@ -194,6 +194,23 @@ void loop() {
Serial.print(F("Z (CH2): ")); Serial.println(z);
Serial.print(F("W (CH3): ")); Serial.println(w);
// Calculate and display CIE chromaticity coordinates and lux
double CIEx, CIEy, lux;
if (sensor.getCIE(&CIEx, &CIEy, &lux)) {
Serial.println(F("\nCIE Coordinates:"));
Serial.print(F("CIE x: ")); Serial.println(CIEx, 8);
Serial.print(F("CIE y: ")); Serial.println(CIEy, 8);
Serial.print(F("Lux: ")); Serial.println(lux, 4);
// Calculate and display color temperature
double colorTemp = sensor.calculateColorTemperature(CIEx, CIEy);
Serial.print(F("Color Temperature: "));
Serial.print(colorTemp, 2);
Serial.println(F(" K"));
} else {
Serial.println(F("\nError calculating CIE coordinates"));
}
// Read and print status flags
uint8_t flags = sensor.getFlags();
Serial.println(F("\nStatus Flags:"));
@ -212,23 +229,6 @@ void loop() {
if (flags == 0) {
Serial.println(F("- No flags set"));
}
// Calculate and display CIE chromaticity coordinates and lux
double CIEx, CIEy, lux;
if (sensor.getCIE(&CIEx, &CIEy, &lux)) {
Serial.println(F("\nCIE Coordinates:"));
Serial.print(F("CIE x: ")); Serial.println(CIEx, 8);
Serial.print(F("CIE y: ")); Serial.println(CIEy, 8);
Serial.print(F("Lux: ")); Serial.println(lux, 4);
// Calculate and display color temperature
double colorTemp = sensor.getColorTemperature();
Serial.print(F("Color Temperature: "));
Serial.print(colorTemp, 2);
Serial.println(F(" K"));
} else {
Serial.println(F("\nError calculating CIE coordinates"));
}
Serial.println();
} else {
Serial.println(F("Error reading sensor data"));