Arduino-Based IoT Project for Food Quality Monitoring

1//Program to
2
3#include <SoftwareSerial.h>
4
5#include <LiquidCrystal.h>
6
7#include  <dht.h>   // include dht sensor library
8
9LiquidCrystal lcd(10, 9, 5, 4, 3,  2);
10
11dht DHT;
12
13float t=0;
14
15float h=0;
16
17#define DHT11_PIN  8
18
19#define LDR_PIN A1
20
21#define MQ3_PIN A0
22
23char data = 0;
24
25int  ldr_read = 0;
26
27int gas_read = 0;
28
29// replace with your channel's thingspeak  API key
30
31String apiKey = "[API KEY FROM THINGSPEAK]";
32
33// connect  10 to TX of Serial USB
34
35// connect 11 to RX of serial USB
36
37SoftwareSerial  ser(12,13); // RX, TX
38
39void setup() 
40
41{                
42
43  //  enable software serial
44
45  ser.begin(9600);
46
47  lcd.begin(16,2);
48
49
50  
51
52 // pinMode(LDR_PIN, INPUT);
53
54  //pinMode(MQ3_PIN, INPUT);
55
56
57  
58
59  lcd.setCursor(1,0);
60
61  lcd.print("**SmarT FooD**");
62
63  lcd.setCursor(3,1);
64
65  lcd.print("MonitorinG");
66
67  Serial.begin(9600);
68
69
70 
71
72  //  reset ESP8266 WiFi connection AT+CIPMUX=1 AT+CWJAP
73
74  ser.println("AT");
75
76  delay(1000);
77
78  ser.println("AT+GMR");
79
80  delay(1000);
81
82  ser.println("AT+CWMODE=3");
83
84  delay(1000);
85
86  ser.println("AT+RST");
87
88  delay(5000);
89
90  ser.println("AT+CIPMUX=1");
91
92  delay(1000);
93
94  String cmd="AT+CWJAP=\\"[YOUR SSID]\\",\\"[PASSWORD]\\"";
95
96  ser.println(cmd);
97
98  delay(1000);
99
100  ser.println("AT+CIFSR");
101
102  delay(1000);
103
104 }
105
106// the loop 
107
108void loop()
109
110{
111
112  lcd.clear();
113
114  ldr_read = analogRead(LDR_PIN);
115
116  lcd.setCursor(0,0);
117
118  lcd.print("LDR-");
119
120  lcd.setCursor(4,0);
121
122  lcd.print(ldr_read);
123
124
125  
126
127  lcd.setCursor(0,1);
128
129  lcd.print("MQ3-");
130
131  gas_read =  analogRead(MQ3_PIN);
132
133  lcd.setCursor(4,1);
134
135  lcd.print(gas_read);
136
137
138  
139
140  int chk = DHT.read11(DHT11_PIN);
141
142  Serial.print("Temperature =  ");
143
144  t = DHT.temperature;
145
146
147 
148
149  //lcd.clear();
150
151  lcd.setCursor(8,0);
152
153  lcd.print("Tem-");
154
155
156 
157
158  lcd.setCursor(12,0);
159
160  lcd.print(t);
161
162  Serial.println(t);
163
164
165 
166
167  Serial.print("Humidity  = ");
168
169  h = DHT.humidity;
170
171  lcd.setCursor(8,1);
172
173  lcd.print("Hum-");
174
175  lcd.setCursor(12,1);
176
177  lcd.print(h);
178
179  Serial.println(h);
180
181
182  
183
184  esp_8266();
185
186}
187
188void esp_8266()
189
190{
191
192   // TCP  connection AT+CIPSTART=4,"TCP","184.106.153.149",80 
193
194    String cmd =  "AT+CIPSTART=4,\\"TCP\\",\\"";
195
196    cmd += "184.106.153.149"; // api.thingspeak.com
197
198    cmd += "\\",80";
199
200    ser.println(cmd);
201
202    Serial.println(cmd);  
203
204    if(ser.find("Error"))
205
206    {
207
208      Serial.println("AT+CIPSTART  error");
209
210      return;
211
212    }
213
214
215 
216
217  // prepare GET  string GET https://api.thingspeak.com/update?api_key=LHAG4NSIYJ5UWS6U&field1=0\
\
218\
\
219
220
221  String getStr = "GET /update?api_key=";
222
223  getStr += apiKey;
224
225  getStr  +="&field1=";
226
227  getStr +=String(t);
228
229  getStr +="&field2=";
230
231  getStr +=String(h);
232
233  getStr +="&field3=";
234
235  getStr +=String(ldr_read);
236
237  getStr +="&field4=";
238
239  getStr +=String(gas_read);
240
241  getStr +=  "\
\
242\
\
243";
244
245  // send data length
246
247  cmd = "AT+CIPSEND=4,";
248
249  cmd += String(getStr.length());
250
251  ser.println(cmd);
252
253  Serial.println(cmd);
254
255  delay(1000);
256
257  ser.print(getStr);
258
259  Serial.println(getStr);
260
261
262    
263
264  // thingspeak needs 15 sec delay between updates
265
266  delay(3000);  
267
268}
269
270