Handheld Geiger Counter with Arduino Nano

1/*********
2  This project has been developed and produced by Pierre  Pennings (December 2019),
3  This Project is about making a handheld Geiger Counter  using a ready made Geiger Counter kit, in a 3D printed handheld radiation detector,  
4  De kit is connected to an Arduino Nano that counts the number of impulses  from the Geiger/Muller tube in a period of 10 seconds and then displays the average  CPM (Counts Per Minute) on a 96*64 OLED color display.
5  The measured CPM is  also displayed as micro Sievert per Hour (with a simple conversion factor of 151)
6  The OLED display also displays the momentary measured amount of impulses (per  second) and displays the measurements as a moving red bar on the display. 
7  The  3D printed housing contains also the 18650-Ion Lithium battery (rechargeble) which  provides the 5V power to the Arduino Nano as well as the Geiger Counter kit and  3,3V for the OLED display.
8  A power-on swith and an external beeper complete  the detector.
9  Upon power-on, the charging level of the 18650 battery is shown  on the color display.
10        
11  This code is licensed under GPL3+ license.
12  
13*********/
14
15#include <Adafruit_GFX.h>
16#include <Adafruit_SSD1331.h>
17#include  <SPI.h>
18                                  //Connections for the OLED display
19#define  sclk 13                           //SCL  (blue wire)
20#define mosi 11                           //SDA  (white wire)
21#define cs   10                           //CS   (grey wire)
22#define  rst  9                            //RES  (green wire)
23#define dc   8                            //DC   (yellow wire)
24
25#define LOGtime 1000                      //Logging time  in milliseconds (1 second)
26#define Minute 60000                      //the period  of 1 minute for calculating the CPM values
27
28#define show endWrite
29#define  clear() fillScreen(0)
30
31// Color definitions
32#define BLACK        0x0000
33#define  BLUE         0x001F
34#define RED          0xF800
35#define GREEN        0x07E0
36#define  CYAN         0x07FF
37#define MAGENTA      0xF81F
38#define YELLOW       0xFFE0  
39#define WHITE        0xFFFF
40
41Adafruit_SSD1331 display = Adafruit_SSD1331(cs,  dc, rst);
42
43int Counts = 0;                           //variable containing  the number of GM Tube events within the LOGtime
44unsigned long previousMillis  = 0;         //variable for storing the previous time
45int AVGCPM = 0;                           //variable  containing the floating average number of counts over a fixed moving window period
46int  TenSecCPM = 0;
47int units = 0;
48int tens = 0;
49int hundreds = 0;
50int thousands  = 0;
51float Sievert = 0;
52
53int COUNTS[10];                         // array  for storing the measured amounts of impulses in 10 consecutive 1 second periods
54int  t = 0;
55
56////////////////////the setup code that follows, will run once after  "Power On" or after a RESET///////////////////
57void setup() {
58
59  Serial.begin(115200);
60  display.begin();
61  display.fillScreen(BLACK);
62  
63  float Battery = analogRead(A3);       //(orange wire)
64  float BattPerc = 100 * (Battery/770);
65  
66  //Serial.print  ("battery value = "); Serial.println (Battery); Serial.print ("battery percentage  = "); Serial.println (BattPerc);
67  display.setCursor(4,4);
68  display.setTextSize(2);
69  display.setTextColor(MAGENTA);
70  display.println("Battery");
71  display.setCursor(4,24);
72  display.print (int (BattPerc)); display.print("."); display.print (int((10*BattPerc)-(10*int(BattPerc))));  display.print(" %");
73  delay(3000);
74  display.fillScreen(BLACK);
75
76  for (int x = 0; x < 10 ; x++) {           //put all data in the Array COUNTS to  0 (Array positions run from 0 to 10; 
77    COUNTS[x] = 0;                          //10  positions covering a period of 10 seconds
78  }
79  
80  attachInterrupt(0, IMPULSE,  FALLING);     //define external interrupt on pin D2/INT0 to start the interupt routine  IMPULSE  (green wire)
81  
82  display.drawRect(0,0,96,64,WHITE);
83  display.setCursor(4,4);
84  display.setTextColor(RED);
85  display.setTextSize(2);
86  display.print("CPM");
87  display.setCursor(50,4);
88  display.setTextSize(1);
89  display.print("10  sec");
90  display.setCursor(50,12);
91  display.print("window");
92  
93  display.setCursor(4,38);
94  display.setTextSize(1);
95  display.setTextColor(GREEN);
96  display.print("uSv/hr");
97  
98  display.drawRect(0,48, 96, 16, YELLOW);
99}
100
101////////////////////////the  loop code that follows, will run repeatedly until "Power Off" or a RESET/////////
102void  loop() 
103{
104  unsigned long currentMillis = millis();
105  if(currentMillis  - previousMillis > LOGtime)
106    {
107    previousMillis = currentMillis;
108
109    COUNTS[t] = Counts;
110    for (int y = 0; y < 10 ; y++) {               //add  all data in the Array COUNTS together 
111    TenSecCPM = TenSecCPM + COUNTS[y];            //and calculate the rolling average CPM over a 10 second period
112    }
113    AVGCPM = 6* TenSecCPM; 
114    TenSecCPM = 0;
115    t++ ;
116    if  (t > 9) { t = 0 ;}
117    
118    //Serial.print ("COUNTS "); Serial.print(t);  Serial.print (" = ");Serial.println (COUNTS[t]);
119    display.fillRect(4,20,90,17,BLACK);           // clear the CPM value field on the display
120    display.setCursor(4,20);
121    display.setTextColor(RED);
122    display.setTextSize(2);
123    display.println(AVGCPM);  
124
125    //Serial.print ("AVGCPM = "); Serial.print (AVGCPM); //Serial.print  ("   CPM = "); Serial.println (CPM);
126    display.fillRect(45,38,50,10,BLACK);          // clear the uSv/Hr value field on the display
127    display.setCursor(45,38);
128    display.setTextColor(GREEN);
129    display.setTextSize(1);
130    
131    Sievert  = (AVGCPM /151.0) ;                                                     //Serial.print  ("  Sievert = "); Serial.println (Sievert);
132    units = int (Sievert);                                                          //Serial.print  ("units = "); Serial.println (units);
133    tens = int ((10*Sievert) - (10*units));                                         //Serial.print ("tens = "); Serial.println  (tens);
134    hundreds = int ((100*Sievert) - (100*units) - (10* tens));                      //Serial.print  ("hundreds = "); Serial.println (hundreds);
135    thousands = int ((1000*Sievert)  - (1000*units) - (100*tens) - (10*hundreds));   //Serial.print ("thousands = ");  Serial.println (thousands);
136    display.print (units); display.print(".");  display.print (tens); display.print (hundreds); display.println (thousands);
137    
138    display.fillRect(1,49,94,14,BLACK);            // clear the CPM indicator  field on the display
139    display.fillRect(1,49,Counts,14,RED);          // fill  the CPM indicator field on the display
140    
141    Counts = 0;
142    }
143}
144//////////////////END  of LOOP////////////////////////////////////
145
146/////////////////////////////////Hereafter  follows the Function for counting the number of impulses from Geiger Counter kit
147void  IMPULSE()
148  {
149  Counts++;
150  }