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| -rw-r--r-- | Detector_Building/Detector_Building.ino | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/Detector_Building/Detector_Building.ino b/Detector_Building/Detector_Building.ino new file mode 100644 index 0000000..e9e71f1 --- /dev/null +++ b/Detector_Building/Detector_Building.ino @@ -0,0 +1,168 @@ +/* + * Detector Building + * Code by Anthony Wang + * Ladue High School Science Olympiad + */ + + +/* + * TODO: + * BUG FIXING: Expect bugs! + */ + + +// Constants +const int LED_R = 4, LED_G = 3, LED_B = 2, THERM = 0; // Device component pins +const double R_k = 10000, V_in = 5, analog_max = 1023; // Device constants + + +// Temperature conversions +inline double f2c(double f) { return (f - 32) * 5 / 9; } // Fahrenheit to Celsius +inline double c2f(double c) { return c * 9 / 5 + 32; } // Celsius to Fahrenheit +inline double k2c(double k) { return k - 273.15; } // Kelvin to Celsius +inline double c2k(double c) { return c + 273.15; } // Celsius to Kelvin +inline double f2k(double f) { return c2k(f2c(f)); } // Fahrenheit to Kelvin +inline double k2f(double k) { return c2f(k2c(k)); } // Kelvin to Fahrenheit + + +// Analog to digital conversion +inline double a2d(int a) { return V_in * a / analog_max; } +inline int d2a(double d) { return d * analog_max / V_in; } + + +// Utility functions +// No C++ standard library :( +void sort(int& a[], int n) { + // Bubble sort + // Slow but n < 30 so OK + // Too lazy to implement a fast sort + for (int i = 0; i < n; i++) { + for (int j = 0; j < n - 1; j++) { + if (a[j] > a[j + 1]) { + int tmp = a[j]; + a[j] = a[j + 1]; + a[j + 1] = tmp; + } + } + } +} + + +// Calibration data +const int n = 3, m = n / 3; // Number of data points, MUST be multiple of 3 +double V[n] = { 2.5, 3.26, 3.96 }; // Voltage measurements +double T[n] = { 25, 39.15, 60 }; // Temperature measurements +double V_mid[m]; // Stores each piecewise segment for binary search +double A[m], B[m], C[m]; // Coefficients for each piecewise component + + +// Calculations +// Steinhart-hart stuff +void calculate() { + sort(V, n); + sort(T, n); + double R[n], L[n], Y[n], G[n]; + for (int i = 0; i < n; i++) R[i] = R_k * (V_in / V[i] - 1); + for (int i = 0; i < n; i++) L[i] = log(R[i]); + for (int i = 0; i < n; i++) Y[i] = 1 / c2k(T[i]); + for (int i = 0; i < n; i += 3) { + G[i + 1] = (Y[i + 1] - Y[i]) / (L[i + 1] - L[i]); + G[i + 2] = (Y[i + 2] - Y[i]) / (L[i + 2] - L[i]); + } + for (int i = 0; i < n; i += 3) { // Don't ask how this works + C[i / 3] = (G[i + 2] - G[i + 1]) / (L[i + 2] - L[i + 1]) / (L[i] + L[i + 1] + L[i + 2]); + B[i / 3] = G[i + 1] - C[i / 3] * (L[i] * L[i] + L[i] * L[i + 1] + L[i + 1] * L[i + 1]); + A[i / 3] = Y[i] - L[i] * (B[i / 3] + L[i] * L[i] * C[i / 3]); + } + for (int i = 0; i < n; i += 3) V_mid[i / 3] = (i ? (V[i - 1] + V[i]) / 2 : V[i]); +} + + +// Arduino stuff +void blink(int pin) { + digitalWrite(pin, HIGH); + delay(1000); + digitalWrite(pin, LOW); +} +void setup() { + Serial.begin(9600); + pinMode(LED_R, OUTPUT); + pinMode(LED_G, OUTPUT); + pinMode(LED_B, OUTPUT); + + // blink(LED_R); + // blink(LED_G); + // blink(LED_B); + + // Debug stuff + /*for (int i = 0; i < m; i++) { + Serial.print("Segment lower bound: "); + Serial.print(i ? V_mid[i - 1] : 0); + Serial.print(" Segment upper bound: "); + Serial.print(V_mid[i]); + Serial.print(" A: "); + Serial.print(A[i], 12); + Serial.print(" B: "); + Serial.print(B[i], 12); + Serial.print(" C: "); + Serial.print(C[i], 12); + Serial.println(); + }*/ +} + + +// Main loop +void loop() { + int V_raw = analogRead(THERM); // Read in raw analog value + double V_out = a2d(V_raw); // Convert analog to digital + double R_t = R_k * (V_in / V_out - 1); // Thermistor resistance + + int s = 0; + while (s < m && V_out > V_mid[s + 1]) s++; // Find correct segment + + double logR_t = log(R_t); + double K = 1.0 / (A[s] + B[s] * logR_t + C[s] * logR_t * logR_t * logR_t); // Steinhart-hart + double C = k2c(K); + double F = c2f(C); + + // LED stuff + if (C <= 25) { + digitalWrite(LED_R, LOW); + digitalWrite(LED_G, LOW); + digitalWrite(LED_B, HIGH); + } + else if (C <= 50) { + digitalWrite(LED_R, LOW); + digitalWrite(LED_G, HIGH); + digitalWrite(LED_B, LOW); + } + else if (C <= 75) { + digitalWrite(LED_R, HIGH); + digitalWrite(LED_G, LOW); + digitalWrite(LED_B, LOW); + } + else { + digitalWrite(LED_R, HIGH); + digitalWrite(LED_G, HIGH); + digitalWrite(LED_B, HIGH); + } + + // Output voltage, temperature + Serial.print("Raw analog reading: "); + Serial.print(V_raw); + Serial.print(" Voltage (V): "); + Serial.print(V_out); + Serial.print(" Temperature (°C): "); + Serial.print(C); + Serial.print(" Temperature (°F): "); // For reference + Serial.print(F); + + // Debug stuff + /*Serial.print(" Segment lower bound: "); + Serial.print(s ? V_mid[s - 1] : 0); + Serial.print(" Segment upper bound: "); + Serial.print(V_mid[s]);*/ + + Serial.println(); + delay(500); +} |