Portable and rechargeable Ultraviolet (UV) radiation meter

1/*
2    UV meter code
3
4    This is the code for the portable UV  meter. Most of it is essentially 
5    code for the OLED 0.96" display, to draw  and print the desired info on it.
6    There is also a setup for the tactile switch,  and readings of the actual UV sensor
7
8    The circuit:
9    * OLED display:  SCL attached to A5 and SDA attached to A4
10    * UV sensor: sensor's OUT pin is  connected to A0
11    * Tactile Switch: The tactile switch is connected D12
12
13    Feel free to use this code and modify it. Just keep it "open source" and share  it with the community. That's what this project is all about, after all!
14    
15    Created and modified throughout the whole of 2022
16    By Davi Salles Leite,  d4visl on the Arduino Hub
17    Modifications (dd/mm/yy): 
18
19    https://create.arduino.cc/projecthub/d4visl/portable-and-rechargeable-ultraviolet-uv-radiation-meter-751c2e?auth_token=740cf17a480a86a9b0df5523606d24a4
20
21*/
22int  i = 0;  // Variable to store values
23int button = 12;  // Pin of the tactile switch  used to change modes
24unsigned long t_1 = millis();   // records millis for the  sun animation on the OLED display
25unsigned long t_2 = millis();   // same as  the above
26int mode = 0;   // sets the initial mode
27
28// include the necessary  libraries
29#include <Wire.h>
30#include <Adafruit_GFX.h>
31#include <Adafruit_SSD1306.h>
32
33#define  SCREEN_WIDTH 128 // OLED display width,  in pixels
34#define SCREEN_HEIGHT 64 //  OLED display height, in pixels
35
36// declare an SSD1306 display object connected  to I2C
37Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);
38
39void  setup() {
40  Serial.begin(9600);
41
42  // initialize OLED display with address  0x3C for 128x64
43  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
44    Serial.println(F("SSD1306  allocation failed"));
45    while (true);
46  }
47
48  delay(2000);         //  wait for initializing
49  display.clearDisplay(); // clear display
50  
51  pinMode(button,  INPUT); // Initialize
52}
53
54void loop() {
55  
56  // Read the tactile switch  for input. If high, then the switch is being pressed.
57  if (digitalRead(button)  == HIGH){
58    mode += 1;    // change the value of mode
59    delay(500); 
60  }
61  
62  // Change the mode
63  if (mode == 0){
64    mode_0(); // call  mode 0
65  }
66  else if (mode == 1){
67    mode_1(); // call mode 1
68  }
69  else if (mode == 2){
70    mode_2(); // call mode 2
71  }
72  else{
73    mode  = 0;  // revert the value of mode to the initial and calls mode 0
74    mode_0();
75  }
76}
77
78/* 
79  Mode 0 
80  Mode 0 shows the following information:
81    * Analog value measured by the sensor - This varies between 0-1023, 
82    but  the maximum value ever registered during testing was 350
83    * A graph to demonstrate  the analog value through a visual aid
84    * Animation of the sun, for aesthetic  purposes
85   
86*/
87void mode_0(){
88  
89  /* This is an animation of the  sun. It starts by drawing a filled in circle in the top left, 
90  then every time  this mode is called, it draws 4 circumferences in a progressively outwards motion,  to represent the sunlight moving away from the sun. 
91  This animation is repeated  every few seconds, and pauses from time to time. 
92  millis() was used to keep  track of this time.*/
93  if (millis() - t_1 > 300){
94    i += 1;
95    t_1  = millis();
96    display.clearDisplay();
97     
98    if (i >= 4){
99      i  = 0;
100    }
101    if (millis() - t_2 < 2000){
102      display.drawCircle(0,0,24,WHITE);
103      display.drawCircle(0,0,28,WHITE);
104    }
105    else{
106      if (millis()  - t_2 > 7000){
107        t_2 = millis();
108      }
109      
110      display.drawCircle(0,0,16  + (i * 2),WHITE);
111      display.drawCircle(0,0,20 + (i * 2),WHITE);
112      
113      if (i < 2){
114      display.drawCircle(0,0,24 + (i * 2), WHITE);
115      }
116      
117      if (i < 1){
118      display.drawCircle(0,0,28 + (i * 2),WHITE);   
119      }  
120    }
121      
122    display.fillCircle(0,0,20,WHITE); //  this is the circle on the top left
123    
124    display.drawRoundRect(105, 10,  20, 45, 3, WHITE); // body of the graphic
125
126    // Set all the desired specs,  such as color and size
127    display.setTextColor(WHITE);
128    display.setTextSize(1);
129    
130    // Set cursor to desired position to print a part of the graphic
131    display.setCursor(106,0);
132    display.println("MAX");
133    
134    //  Set cursor to desired position to print a part of the graphic
135    display.setCursor(106,57);
136    display.println("MIN");
137      
138    // Set specs for text
139    display.setTextColor(WHITE);
140    display.setTextSize(3);
141    
142    // Set cursor to desired position to  print text
143    display.setCursor(SCREEN_WIDTH / 2 - 10, 0);
144    display.println("UV");
145
146    float media = 0; // variable used to calculate the mean of a series of 5 values
147
148    // read the sensor 5 times and find the sum of the values
149    for (int j  = 0;  j < 5; j++){
150      int sensor_value = analogRead(A0); // read the sensor  pin
151      media += sensor_value; // add value to media
152    }
153
154    Serial.println(media);  // print media to serial monitor 
155
156    // find the mean of the measured values,  and round the result, to diminish the effect of current oscillations
157    media  = media/5; 
158    media = round(media);
159
160    // print mean to serial monitor
161    Serial.print("Media:");
162    Serial.println(media);
163
164    // set the  cursor depending on the number of algarisms, so that the number is centralized
165    if (media <= 9){
166      display.setCursor(63,30);
167    }
168    else if(media  <= 99){
169      display.setCursor(54,30);
170    }
171    else{
172      display.setCursor(42,30);
173    }
174    
175    display.print(int(media)); // print the rounded mean sensor  value to the display
176      
177    display.setTextSize(1); // change text size
178
179    // draw 4 lines to separate the levels of the graphic  
180    for (int j =  9; j <= 36 ; j += 9 ){
181      display.fillRect(105, 55 - j, 20, 1, WHITE); //  what is a line if not a rectangle of height = 1 pixel?
182    }
183
184    // fill  the levels of the graphic, according to the media (rounded mean value of the sensor's  readings)
185    if(media > 0){
186      // "Very high" on the UV index scale
187      if(media >= 290){ 
188        display.fillRoundRect(105, 10, 20, 45, 3, WHITE);
189      }   
190      // "High" on the UV index scale
191      else if(media >=  256){
192        display.fillRoundRect(105, 19, 20, 36, 3, WHITE);
193      }
194      // "Moderate" on the UV index scale
195      else if(media >= 178){
196        display.fillRoundRect(105, 28, 20, 27, 3, WHITE);
197      }
198      //  "Low" on the UV index scale
199      else if(media >= 121){
200        display.fillRoundRect(105,  37, 20, 18, 3, WHITE);
201        }
202      // Any UV radiation detected (0 < UV  < 1)
203      else{
204        display.fillRoundRect(105, 46, 20, 9, 3, WHITE);
205      }
206    }
207      
208    display.display(); // display all the drawn information
209  }
210}
211
212/*
213 
214 Mode 1
215 Mode 1's purpose is to showcase the approximation  of the UV index, along with a visual aid (graph), 
216 and the risk of harm from  unprotected sun exposure, for the average adult.
217 
218*/
219
220void mode_1(){
221  float media = 0; // variable used to calculate the mean of a series of 5 values
222
223  // clear display and change cursor position and text size
224  display.clearDisplay();  
225  display.setCursor(0,0);
226  display.setTextSize(1);
227  display.println("UV  INDEX"); // print desired text
228
229  display.drawTriangle(93,59,66,5,120,5,  WHITE); // draw body of the graph
230
231  // draw the lines of the graph
232  for  (int j = 0; j < 9; j ++){
233    display.drawTriangle(93, 59, 66 + (j*3), 5 + (j*6),  120 - (j*3), 5 + (j*6), WHITE);
234  }
235  
236  // read the sensor 5 times and  find the sum of the values
237  for (int j = 0;  j < 5; j++){
238    int sensor_value  = analogRead(A0);
239    media += sensor_value;
240  }
241  
242  Serial.println(media);  // print media to serial monitor
243
244  // find the mean of the measured values,  and round the result, to diminish the effect of current oscillations
245  media  = media / 5;
246  media = round(media);
247
248  // print mean to serial monitor
249  Serial.print("Media:");
250  Serial.println(media);
251
252  // display the  value of the UV index, risk of harm from unprotected sun exposure, for the average  adult , and fill the graph, according to the according to the media (rounded mean  value of the sensor's readings)
253  if (media > 5){
254    if (media < 69){
255      display.fillTriangle(93,59,90,53,96,53, WHITE); // fill the graph
256      cursor0();  // set cursor to standardised position
257      display.println("<1"); // UV index
258      cursor1(); // set cursor to standardised position
259      display.println("Baixo");  // risk of harm
260    }
261    else if(media <= 121){
262      display.fillTriangle(93,59,90,53,96,53,  WHITE); // fill the graph
263      cursor0(); // set cursor to standardised position
264      display.println("1"); // UV index
265      cursor1(); // set cursor to standardised  position
266      display.println("Baixo");  // risk of harm
267    }
268    else  if(media <= 178){
269      display.fillTriangle(93,59,87,47,99,47, WHITE); // fill  the graph
270      cursor0(); // set cursor to standardised position
271      display.println("2");  // UV index
272      cursor1(); // set cursor to standardised position
273      display.println("Baixo");  // risk of harm
274    }
275    else if(media <= 211){
276      display.fillTriangle(93,59,84,41,102,41,  WHITE); // fill the graph
277      cursor0(); // set cursor to standardised position
278      display.println("3"); // UV index
279      cursor2(); // set cursor to standardised  position
280      display.println("Moderado"); // risk of harm
281    }
282    else  if(media <= 237){
283      display.fillTriangle(93,59,81,35,105,35, WHITE); // fill  the graph
284      cursor0(); // set cursor to standardised position
285      display.println("4");  // UV index
286      cursor2(); // set cursor to standardised position
287      display.println("Moderado");  // risk of harm
288    }
289    else if(media <= 256){
290      display.fillTriangle(93,59,78,29,108,29,  WHITE); // fill the graph
291      cursor0(); // set cursor to standardised position
292      display.println("5"); // UV index
293      cursor2(); // set cursor to standardised  position
294      display.println("Moderado"); // risk of harm
295    }
296    else  if(media <= 273){
297      display.fillTriangle(93,59,75,23,111,23, WHITE); // fill  the graph
298      cursor0(); // set cursor to standardised position
299      display.println("6");  // UV index
300      cursor1(); // set cursor to standardised position
301      display.println("Alto");  // risk of harm
302    }
303    else if(media <= 290){
304      display.fillTriangle(93,59,72,17,114,17,  WHITE); // fill the graph
305      cursor0(); // set cursor to standardised position
306      display.println("7"); // UV index
307      cursor1(); // set cursor to standardised  position
308      display.println("Alto"); // risk of harm
309    }
310    else  if(media <= 311){
311      display.fillTriangle(93,59,69,11,117,11, WHITE); // fill  the graph
312      cursor0(); // set cursor to standardised position
313      display.println("8");  // UV index
314      cursor2(); // set cursor to standardised position
315      display.println("Muito  Alto"); // risk of harm
316    }
317    else if(media > 311){
318      display.fillTriangle(93,59,66,5,120,5,  WHITE); // fill the graph
319      cursor0(); // set cursor to standardised position
320      display.println("9+"); // UV index
321      cursor2(); // set cursor to  standardised position
322      display.println("Muito Alto"); // risk of harm
323    }
324  }
325  else{
326    cursor0(); // set cursor to standardised position
327    display.println("0"); // UV index
328    cursor1(); // set cursor to standardised  position
329    display.println("Baixo"); //  risk of harm
330  }
331  display.display();  // display the drawn info
332}
333
334/*
335 Mode 2
336 Mode 2 presents the user  with a url (reduced with tinyurl.com) that they can use to  access a google drive  folder.
337 This folder contains manuals and guides, explaining exactly how to use  and maintain the UV meter. It also contains a project log and tutorial, in portuguese,  
338 along with other informations about the device, and a link to access the arduino  hub project tutorial (in english). There is also a photo gallery.
339 */
340void  mode_2(){
341  display.clearDisplay(); // clear display
342
343  // change the text  size and cursor position
344  display.setTextSize(2);
345  display.setCursor(30,0);
346  display.println("Acesse"); // print text
347  
348  // change the text size  and cursor position
349  display.setTextSize(1);
350  display.setCursor(14,32);
351  display.drawRoundRect(9, 28, 110, 16, 3, WHITE); // draw rectangle to contain  the url
352  display.print("tinyurl.com/senuv"); // print text
353  display.display();  // display the drawn info
354  
355}
356
357// standardised cursor position for  printing the UV index
358void cursor0(){
359  display.setCursor(10,15);
360  display.setTextSize(4);
361}
362
363//  standardised cursor position for printingthe risk of harm
364void cursor1(){
365  display.setCursor(5,50);
366  display.setTextSize(1); 
367}
368
369// other standardised  cursor position for printing the risk of harm
370void cursor2(){
371  display.setCursor(0,50);
372  display.setTextSize(1);
373}
374