Members-Only Vending Machine with Customer ID and Automatic Payment

1#include <SPI.h>
2#include <MFRC522.h>
3
4int RST_PIN = 9;
5int SS_PIN = 10;
6
7String UID;
8
9MFRC522 mfrc522(SS_PIN, RST_PIN);
10
11void setup() {
12  Serial.begin(9600);
13  SPI.begin();
14  mfrc522.PCD_Init();
15  Serial.write(",");
16}
17
18void loop() {
19  if (!mfrc522.PICC_IsNewCardPresent()) {
20    return;
21  }
22  else if (!mfrc522.PICC_ReadCardSerial()) {
23    return;
24  }
25  for (int i=0; i < mfrc522.uid.size; i++) {
26    UID += (mfrc522.uid.uidByte[i] < 0x10 ? "0" : "");
27    UID += String(mfrc522.uid.uidByte[i], HEX);
28  }
29  for (int i=0; i < UID.length(); i++) {
30    Serial.write(char(UID[i]));
31  }
32  UID = "";
33  delay(5000);
34}

1#include <Servo.h>
2#include <LiquidCrystal_I2C.h>
3#include <SPI.h>
4#include <SD.h>
5
6int CS_PIN = 53;
7int redButton = 22;
8int yellowButton = 24;
9int greenButton = 26;
10int blueButton = 28;
11
12LiquidCrystal_I2C lcd(0x27, 20, 4);
13
14int redServoPin = 8;
15int yellowServoPin = 9;
16int greenServoPin = 10;
17int blueServoPin = 11;
18
19bool redButtonPressed = 0;
20bool yellowButtonPressed = 0;
21bool greenButtonPressed = 0;
22bool blueButtonPressed = 0;
23
24Servo myServo;
25char data;
26String UID;
27File myFile;
28File prevFile;
29bool commStart;
30String checkUID;
31double preTime;
32bool servoTurned = 0;
33
34void setup() {
35  SPI.begin();
36  Serial.begin(9600);
37  lcd.init();
38  lcd.backlight();
39  pinMode(redServoPin, OUTPUT);
40  pinMode(yellowServoPin, OUTPUT);
41  pinMode(greenServoPin, OUTPUT);
42  pinMode(blueServoPin, OUTPUT);
43  if (!SD.begin(CS_PIN)) {
44    Serial.println("Initialization failed!");
45    while (1);
46  }
47  Serial.println("Initialization succeeded!");
48}
49
50void loop() {
51  servoTurned = 0;
52  if (Serial.available()) {
53    data = Serial.read();
54    UID += data;
55    Serial.println(data);
56  }
57  if (UID.length() == 8) {
58    if (UID.lastIndexOf(",") >= 0) {
59      UID = UID.substring(UID.lastIndexOf(",")+1);
60      for (int i=0; i<=UID.lastIndexOf(","); i++) {
61        data = Serial.read();
62        UID += data;
63      }
64    }
65    Serial.end();
66    Serial.begin(9600);
67    Serial.print("UID: ");
68    Serial.println(UID);
69    checkUID = CheckUID(UID);
70    if (checkUID == "not registered") {
71      Serial.println("void loop: not registered");
72      UID ="";
73      return;
74    }
75    else if (checkUID == "recharge") {
76      Serial.println("void loop: recharge");
77      UID ="";
78      return;
79    }
80    lcd.clear();
81    lcd.print("Choose a snack...");
82    preTime = millis();
83    Serial.println(preTime);
84    while (millis() - preTime < 10000) {
85      Serial.println(millis() - preTime);
86      if (digitalRead(redButton)) {
87        myServo.attach(redServoPin);
88        ServoAction("Red");
89        servoTurned = 1;
90        lcd.clear();
91        break;
92      }
93      else if (digitalRead(yellowButton)) {
94        myServo.attach(yellowServoPin);
95        ServoAction("Yellow");
96        servoTurned = 1;
97        lcd.clear();
98        break;
99      }
100      else if (digitalRead(greenButton)) {
101        myServo.attach(greenServoPin);
102        ServoAction("Green");
103        servoTurned = 1;
104        lcd.clear();
105        break;
106      }
107      else if (digitalRead(blueButton)) {
108        myServo.attach(blueServoPin);
109        ServoAction("Blue");
110        servoTurned = 1;
111        lcd.clear();
112        break;
113      }
114      else {
115        continue;
116      }
117    }
118    lcd.clear();
119    if (servoTurned == 0) {
120      lcd.println("Paused too long.");
121      delay(1000);
122      lcd.clear();
123      lcd.println("Have a nice day!");
124      delay(2000);
125      lcd.clear();
126      UID = "";
127      return;
128    }
129    DecreaseCount(checkUID);
130    UID = "";
131    return;
132  }
133}
134
135String CheckUID(String UID) {
136  Serial.println(UID);
137  myFile = SD.open("SA_cards.csv");
138  String contents = "";
139  bool uidExists = 0;
140  if (myFile) {
141    Serial.println(myFile.available());
142    while (myFile.available()) {
143      char character = (char)myFile.read();
144      contents += character;
145      if (character == '\n') {
146        Serial.println(contents.substring(contents.lastIndexOf(',') + 1).length());
147        Serial.println(UID);
148        if (contents.substring(contents.lastIndexOf(',') + 1, contents.lastIndexOf(',') + 9).equals(UID)) {
149          uidExists = 1;
150          break;
151        }
152        else {
153          contents = "";
154        }
155      }
156    }
157    Serial.println("While loop ended");
158    if (uidExists == false) {
159      lcd.clear();
160      lcd.setCursor(0,0);
161      lcd.print("Not a registered");
162      lcd.setCursor(0,2);
163      lcd.print("card");
164      delay(2000);
165      lcd.setCursor(0,1);
166      lcd.clear();
167      return "not registered";
168    }
169    myFile.close();
170    Serial.println(contents);
171  }
172  else {
173    lcd.clear();
174    lcd.print("error opening SA_cards.csv");
175  }
176  char items[][10] = {};
177  int startIndex = 0;
178  int endIndex = 0;
179  int itemNum = -1;
180  while (true) {
181    endIndex += 1;
182    if (contents.charAt(endIndex) == '\n' || contents.charAt(endIndex) == ',') {
183      itemNum += 1;
184      contents.substring(startIndex, endIndex).toCharArray(items[itemNum],sizeof(items[itemNum]));
185      Serial.println(String(items[itemNum]));
186      startIndex = endIndex + 1;
187    }
188    if (endIndex==contents.length()-1) {
189      Serial.println("Items setting successful");
190      break;
191    }
192  }
193  Serial.println(itemNum);
194  for (int i=0; i <= itemNum; i++) {
195    Serial.println("New item:");
196    Serial.println(String(items[i]));
197  }
198
199  String name = items[0];
200  int payCount = String(items[2]).toInt();
201  Serial.print("payCount: ");
202  Serial.println(payCount);
203  lcd.clear();
204  lcd.print("Hi " + name);
205  delay(2000);
206  if (payCount > 0) {
207    return contents;
208  }
209  else {
210    lcd.clear();
211    lcd.print("Recharge your card");
212    delay(2000);
213    lcd.clear();
214    return "recharge";
215  }
216}
217
218void ServoAction(String color) {
219  Serial.print(color);
220  Serial.println(" pressed");
221  lcd.clear();
222  lcd.print(color);
223  lcd.print(" pressed");
224  
225  myServo.write(60);
226  delay(1830);
227  myServo.detach();
228  delay(500);
229  lcd.clear();
230}
231
232void DecreaseCount(String contents) {
233  Serial.begin(9600);
234  prevFile = SD.open("SA_cards.csv");
235  String prevFileContents = "";
236  if (prevFile) {
237    while (prevFile.available()) {
238      char data = (char)prevFile.read();
239      prevFileContents += data;
240    }
241  }
242  prevFile.close();
243  Serial.println(prevFileContents);
244  int startIndex = 0;
245  int endIndex = 0;
246  while (true) {
247    endIndex += 1;
248    if (prevFileContents.charAt(endIndex) == '\n') {
249      String piece = prevFileContents.substring(startIndex, endIndex+1);
250      if (piece == contents) {
251        piece = piece.substring(0, piece.length()-11);
252        int payCount = piece.substring(piece.lastIndexOf(',')+1).toInt();
253        payCount--;
254        piece = piece.substring(0, piece.lastIndexOf(','));
255        contents = piece + ',' + payCount + ',' + contents.substring(contents.length()-10);
256        prevFileContents = prevFileContents.substring(0, prevFileContents.substring(0, endIndex).lastIndexOf('\n')+1) + contents + prevFileContents.substring(endIndex+1);
257        break;
258      }
259      startIndex = endIndex + 1;
260      endIndex += 1;
261    }
262  }
263  Serial.println("test");
264  Serial.println(prevFileContents);
265  myFile = SD.open("SA_cards.csv", FILE_WRITE | O_TRUNC);
266  myFile.print(prevFileContents);
267  myFile.close();
268}