uC1ZGNqh

1/*
2  
3 * Description:  Distance measurement using ultrasonic HC-SR04 and ESP32 connected to AskSensors
4 *  Author: https://asksensors.com, 2018 - 2019
5 *  github: https://github.com/asksensors
6 */
7 
8#include <WiFi.h>
9#include <WiFiMulti.h>
10#include <HTTPClient.h>
11
12// utlrasonic pinout
13#define ULTRASONIC_TRIG_PIN     5   // pin TRIG 
14#define ULTRASONIC_ECHO_PIN     4 // pin ECHO 
15
16
17WiFiMulti WiFiMulti;
18HTTPClient ask;
19// TODO: user config
20const char* ssid     = "............."; //Wifi SSID
21const char* password = "............."; //Wifi Password
22String apiKeyIn = "............."; // API Key
23const unsigned int writeInterval = 25000; // write interval (in ms)
24// ASKSENSORS API host config
25const char* host = "api.asksensors.com";  // API host name
26const int httpPort = 80;      // port
27  
28void setup(){
29  
30  // open serial
31  Serial.begin(9600);
32  Serial.println("*****************************************************");
33  Serial.println("********** Program Start : Connect ESP32 to AskSensors.");
34  Serial.println("Wait for WiFi... ");
35
36  // connecting to the WiFi network
37  WiFiMulti.addAP(ssid, password);
38  while (WiFiMulti.run() != WL_CONNECTED) {
39    Serial.print(".");
40    delay(500);
41  }
42  // connected
43  Serial.println("WiFi connected");
44  Serial.println("IP address: ");
45  Serial.println(WiFi.localIP());
46
47  // ultraonic setup 
48  pinMode(ULTRASONIC_TRIG_PIN, OUTPUT);
49  pinMode(ULTRASONIC_ECHO_PIN, INPUT);
50  
51}
52
53
54void loop(){
55
56  // Use WiFiClient class to create TCP connections
57  WiFiClient client;
58  // measure distance 
59  long duration, distance;
60  digitalWrite(ULTRASONIC_TRIG_PIN, LOW);  
61  delayMicroseconds(2); 
62  
63  digitalWrite(ULTRASONIC_TRIG_PIN, HIGH);
64  delayMicroseconds(10); 
65  
66  digitalWrite(ULTRASONIC_TRIG_PIN, LOW);
67  duration = pulseIn(ULTRASONIC_ECHO_PIN, HIGH);
68  distance = (duration/2) / 29.1;
69  Serial.print("********** Ultrasonic Distance: ");
70  Serial.print(distance);
71  Serial.println(" cm");
72
73  if (!client.connect(host, httpPort)) {
74    Serial.println("connection failed");
75    return;
76  }else {
77
78    // Create a URL for the request
79    String url = "https://api.asksensors.com/write/";
80    url += apiKeyIn;
81    url += "?module1=";
82    url += distance;
83    
84    Serial.print("********** requesting URL: ");
85    Serial.println(url);
86   
87    ask.begin(url); //Specify the URL
88  
89    //Check for the returning code
90    int httpCode = ask.GET();          
91 
92    if (httpCode > 0) { 
93 
94        String payload = ask.getString();
95        Serial.println(httpCode);
96        Serial.println(payload);
97      } else {
98      Serial.println("Error on HTTP request");
99    }
100 
101    ask.end(); //End 
102    Serial.println("********** End ");
103    Serial.println("*****************************************************");
104
105  }
106
107  client.stop();  // stop client
108  
109  delay(writeInterval);    // delay
110}