Charles Tritt / Mbed 2 deprecated Nightlight2

Smart of night demonstration project. Color of light fades from blue to green to red as it gets darker.

Dependencies:   mbed

Fork of Nightlight2 by Charles Tritt

main.cpp@4:aa100356f053, 2017-03-30 (annotated)

Committer:
CSTritt
Date:
Thu Mar 30 23:59:22 2017 +0000
Revision:
4:aa100356f053
Parent:
2:5682a72277ed 
No functional changes. Commited and publish to correct repository problems.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
CSTritt 0:8ed2f4a2a2fe 1 /*
CSTritt 2:5682a72277ed 2 Project: Nightlight2
CSTritt 0:8ed2f4a2a2fe 3 File: main.cpp
CSTritt 0:8ed2f4a2a2fe 4
CSTritt 2:5682a72277ed 5 See Word document.
CSTritt 0:8ed2f4a2a2fe 6
CSTritt 0:8ed2f4a2a2fe 7 Written by: Dr. C. S. Tritt
CSTritt 0:8ed2f4a2a2fe 8 Created: 3/26/17 (v. 1.0)
CSTritt 0:8ed2f4a2a2fe 9
CSTritt 0:8ed2f4a2a2fe 10 */
CSTritt 0:8ed2f4a2a2fe 11 #include "mbed.h"
CSTritt 0:8ed2f4a2a2fe 12
CSTritt 2:5682a72277ed 13 const int HIGH = 1; // Inclusion is optional, but makes code more readable.
CSTritt 2:5682a72277ed 14 const int LOW = 0; // Inclusion is optional, but makes code more readable.
CSTritt 2:5682a72277ed 15
CSTritt 2:5682a72277ed 16 const float br_min = 0.070; // Read from serial stream and enter.
CSTritt 2:5682a72277ed 17 const float br_max = 0.430; // Read from serial stream and enter.
CSTritt 2:5682a72277ed 18 const float k_1 = 0.7; // These values work well...
CSTritt 2:5682a72277ed 19 const float k_2 = 0.5;
CSTritt 2:5682a72277ed 20 const float k_3 = 0.3;
CSTritt 2:5682a72277ed 21 const float all_off = br_min + k_1*(br_max - br_min); // Thresholds... All off.
CSTritt 2:5682a72277ed 22 const float blu_grn = br_min + k_2*(br_max - br_min); // Blue-green fade.
CSTritt 2:5682a72277ed 23 const float grn_red = br_min + k_3*(br_max - br_min); // Green-red fade.
CSTritt 0:8ed2f4a2a2fe 24
CSTritt 2:5682a72277ed 25 AnalogIn photocell(A1); // Create object for photocell.
CSTritt 2:5682a72277ed 26 PwmOut red(D9), grn(D10), blu(D11); // Create objects for LED connected pins.
CSTritt 0:8ed2f4a2a2fe 27
CSTritt 0:8ed2f4a2a2fe 28 int main() {
CSTritt 2:5682a72277ed 29 float brightness; // 0 to 1 max. range. Larger indicates brighter light.
CSTritt 0:8ed2f4a2a2fe 30
CSTritt 2:5682a72277ed 31 printf("\nSmart nightlight example\n"); // ID software.
CSTritt 0:8ed2f4a2a2fe 32
CSTritt 0:8ed2f4a2a2fe 33 while(true) {
CSTritt 2:5682a72277ed 34 brightness = photocell; // Read light level (0 to 1).
CSTritt 2:5682a72277ed 35 printf("Value = %f\n", brightness); // Send as text via serial port.
CSTritt 2:5682a72277ed 36 if (brightness > all_off) { // Bright light. All LEDs off.
CSTritt 2:5682a72277ed 37 red = LOW;
CSTritt 2:5682a72277ed 38 grn = LOW;
CSTritt 2:5682a72277ed 39 blu = LOW;
CSTritt 2:5682a72277ed 40 }
CSTritt 2:5682a72277ed 41 else if (brightness > blu_grn) { // Blue to green fade.
CSTritt 2:5682a72277ed 42 red = LOW;
CSTritt 2:5682a72277ed 43 grn = (all_off - brightness)/(all_off - blu_grn);
CSTritt 2:5682a72277ed 44 blu = 1.0f - grn;
CSTritt 0:8ed2f4a2a2fe 45 }
CSTritt 2:5682a72277ed 46 else if (brightness > grn_red) { // Green to red fade.
CSTritt 2:5682a72277ed 47 red = (blu_grn - brightness)/(blu_grn - grn_red);
CSTritt 2:5682a72277ed 48 grn = 1.0f - red;
CSTritt 2:5682a72277ed 49 blu = LOW;
CSTritt 0:8ed2f4a2a2fe 50 }
CSTritt 2:5682a72277ed 51 else { // Red on full intensity.
CSTritt 2:5682a72277ed 52 red = HIGH;
CSTritt 2:5682a72277ed 53 grn = LOW;
CSTritt 2:5682a72277ed 54 blu = LOW;
CSTritt 2:5682a72277ed 55 }
CSTritt 2:5682a72277ed 56 wait(0.1); // Delay 100 ms
CSTritt 0:8ed2f4a2a2fe 57 }
CSTritt 4:aa100356f053 58 }