The RGB Revealer: Unveiling Color with Arduino and TFT

1#include <SPI.h>
2#include <Adafruit_GFX.h>
3#include <Adafruit_ILI9341.h> // This assumes you are using the ILI9341-based TFT display
4
5// Define the pin connections for the TFT display
6#define TFT_CS 10      // Chip select pin
7#define TFT_RST 9      // Reset pin
8#define TFT_DC 8       // Data/Command pin
9#define TFT_MOSI 11    // SPI MOSI (Master Out Slave In) pin
10#define TFT_SCK 13     // SPI SCK (Clock) pin
11#define TFT_MISO 12    // SPI MISO (Master In Slave Out) pin
12
13// Create an instance of the Adafruit_ILI9341 class with specified pin connections
14Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC, TFT_MOSI, TFT_SCK, TFT_RST, TFT_MISO);
15
16//push button variables
17int push_button_pin = 4;
18bool button_released = true;
19
20// Define pin numbers for the color sensor and output
21const int out = 7; 
22const int s0 = 3;
23const int s1 = 2;  
24const int s2 = 6;  
25const int s3 = 5;  
26
27// Variables to store the frequency / pulse duration for Red, Blue, and Green color
28int pulse_duration_red, pulse_duration_blue, pulse_duration_green;
29
30//Variables to store value of Red, Blue, and Green color 
31int red_color, blue_color, green_color;
32
33//Variables to store the lowest and highest pulse duration for Red, Blue, and Green color.
34int min_duration_red, min_duration_blue, min_duration_green;
35int max_duration_red, max_duration_blue, max_duration_green;
36
37    
38void setup()   
39{  
40   // Initialize the TFT display
41  tft.begin();
42  // Set display rotation (1 for 90 degrees clockwise)
43  tft.setRotation(1);
44    // Set text size
45  tft.setTextSize(2);
46
47
48
49  //Setting up push button pin
50  pinMode(push_button_pin, INPUT);
51  digitalWrite(push_button_pin, HIGH);
52
53
54  //Setting lowest and highest pulse duration for Red, Blue, and Green color as noted during the test run
55  min_duration_red = 9;
56  max_duration_red = 53;
57  min_duration_blue = 5;
58  max_duration_blue = 40;
59  min_duration_green = 6;
60  max_duration_green = 50;
61
62  // Start serial communication at 9600 bps
63  Serial.begin(9600); 
64
65  // Set pin modes for the color sensor and output
66  pinMode(s0, OUTPUT);  
67  pinMode(s1, OUTPUT);  
68  pinMode(s2, OUTPUT);  
69  pinMode(s3, OUTPUT);  
70  pinMode(out, INPUT);  
71
72  // Set initial conditions for frequency scaling
73  digitalWrite(s0, HIGH);  
74  digitalWrite(s1, HIGH);  
75}  
76
77
78void loop() 
79{  
80   //Reading push button state
81   int PinState = digitalRead(push_button_pin);
82   //Detecting the color when push button is pressed. Avoid recalling the color function until push button
83   //released and pressed again.
84   if((PinState == 0) && (button_released == true)){
85     button_released = false;
86     color();
87   }
88   if((button_released == false) && (PinState == 1)){
89     button_released = true;
90   }
91   
92}
93
94
95// Function to detect and print the dominant color
96void color()  
97{    
98  
99  // Set the sensor to detect the red color
100  digitalWrite(s2, LOW);  
101  digitalWrite(s3, LOW);   
102  //small pause
103  delay(50); 
104  // Measure the pulse duration (frequency) for the red color
105  pulse_duration_red = pulseIn(out, LOW);
106  //updating the min pulse duration for red if smaller than previous min pulse duration
107  if(pulse_duration_red < min_duration_red){
108    min_duration_red = pulse_duration_red;
109  }
110  //updating the max pulse duration for red if smaller than previous max pulse duration
111  if(pulse_duration_red > max_duration_red){
112    max_duration_red = pulse_duration_red; 
113  }
114
115
116  // Set the sensor to detect the blue color
117  digitalWrite(s2, LOW);
118  digitalWrite(s3, HIGH); 
119  //small pause
120  delay(50);  
121  // Measure the pulse duration (frequency) for the blue color
122  pulse_duration_blue = pulseIn(out, LOW);
123  //updating the min pulse duration for blue if smaller than previous min pulse duration
124  if(pulse_duration_blue < min_duration_blue){
125    min_duration_blue = pulse_duration_blue;
126  }
127  //updating the max pulse duration for blue if smaller than previous max pulse duration
128  if(pulse_duration_blue > max_duration_blue){
129    max_duration_blue = pulse_duration_blue; 
130  }
131
132
133  // Set the sensor to detect the Green color
134  digitalWrite(s2, HIGH);
135  digitalWrite(s3, HIGH);  
136  //small pause
137  delay(50);  
138  // Measure the pulse duration (frequency) for the green color
139  pulse_duration_green = pulseIn(out, LOW);
140  //updating the min pulse duration for green if smaller than previous min pulse duration
141  if(pulse_duration_green < min_duration_green){
142   min_duration_green = pulse_duration_green;
143  }
144  //updating the max pulse duration for green if smaller than previous max pulse duration
145  if(pulse_duration_green > max_duration_green){
146   max_duration_green = pulse_duration_green; 
147  }
148
149 //using the map function to get Red, Blue, Green color values, between 0 and 255, from pulse duration
150  red_color = map(pulse_duration_red, min_duration_red, max_duration_red, 255, 0);
151  green_color = map(pulse_duration_green, min_duration_green, max_duration_green, 255, 0);
152  blue_color = map(pulse_duration_blue, min_duration_blue, max_duration_blue, 255, 0);
153
154 //Using the RGB value as a background color of the TFT screen  
155  uint16_t rgbColor = tft.color565(red_color, green_color, blue_color);
156  tft.fillScreen(rgbColor);
157
158  //printing RGB value on tft screen.
159  // Set the cursor position for text drawing (coordinates 50, 50)
160  tft.setCursor(30, 50);
161  //If background is dark, using light font for the text. 
162  //If background is light, using dark font for the text.
163  //using luminance formula, R, G, and B are the RGB values normalized to the range [0, 1]
164  if(get_luminance(float(red_color)/255.0, float(green_color)/255.0, float(blue_color)/255.0) > 0.5){ //background is light color
165    //Dark font color for light background
166    // Set text color to black
167    tft.setTextColor(ILI9341_BLACK);
168  }
169  else{//background is dark color
170    //Light font color for dark background
171    // Set text color to white
172    tft.setTextColor(ILI9341_WHITE);
173  }
174  //printing on the TFT
175  tft.print("RGB ( "+String(red_color)+" , "+String(green_color)+" , "+String(blue_color)+" ) ");
176
177}
178
179
180
181float get_luminance(float R, float G, float B){
182    float luminance = 0.2126 * R + 0.7152 * G + 0.0722 * B;
183    return luminance;
184 }