I am trying to upload data to mySQL database using an ESP32. The code for posting the data is pretty standard and I have searched for different ways of doing this, but this seems to be the most common way using ESP32. However when trying to post the data I get "Error code: -1".
I have absolutely no idea what this means and how I can fix it. I've tried searching on the web, but have not found anything. Any idea on what is causing this issue and how I can fix it? I'll post the code below.
#ifdef ESP32
#include <WiFi.h>
#include <HTTPClient.h>
#else
#include <ESP8266WiFi.h>
#include <ESP8266HTTPClient.h>
#include <WiFiClient.h>
#endif
#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BME280.h>
// Replace with your network credentials
const char* ssid = "REPLACE_WITH_YOUR_SSID";
const char* password = "REPLACE_WITH_YOUR_PASSWORD";
// REPLACE with your Domain name and URL path or IP address with path
const char* serverName = "http://example.com/post-esp-data.php";
// Keep this API Key value to be compatible with the PHP code provided in the project page.
// If you change the apiKeyValue value, the PHP file /post-esp-data.php also needs to have the same key
String apiKeyValue = "tPmAT5Ab3j7F9";
String sensorName = "BME280";
String sensorLocation = "Office";
/*#include <SPI.h>
#define BME_SCK 18
#define BME_MISO 19
#define BME_MOSI 23
#define BME_CS 5*/
#define SEALEVELPRESSURE_HPA (1013.25)
Adafruit_BME280 bme; // I2C
//Adafruit_BME280 bme(BME_CS); // hardware SPI
//Adafruit_BME280 bme(BME_CS, BME_MOSI, BME_MISO, BME_SCK); // software SPI
void setup() {
Serial.begin(115200);
WiFi.begin(ssid, password);
Serial.println("Connecting");
while(WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("");
Serial.print("Connected to WiFi network with IP Address: ");
Serial.println(WiFi.localIP());
// (you can also pass in a Wire library object like &Wire2)
bool status = bme.begin(0x76);
if (!status) {
Serial.println("Could not find a valid BME280 sensor, check wiring or change I2C address!");
while (1);
}
}
void loop() {
//Check WiFi connection status
if(WiFi.status()== WL_CONNECTED){
HTTPClient http;
// Your Domain name with URL path or IP address with path
http.begin(serverName);
// Specify content-type header
http.addHeader("Content-Type", "application/x-www-form-urlencoded");
// Prepare your HTTP POST request data
String httpRequestData = "api_key=" + apiKeyValue + "&sensor=" + sensorName
+ "&location=" + sensorLocation + "&value1=" + String(bme.readTemperature())
+ "&value2=" + String(bme.readHumidity()) + "&value3=" + String(bme.readPressure()/100.0F) + "";
Serial.print("httpRequestData: ");
Serial.println(httpRequestData);
// You can comment the httpRequestData variable above
// then, use the httpRequestData variable below (for testing purposes without the BME280 sensor)
//String httpRequestData = "api_key=tPmAT5Ab3j7F9&sensor=BME280&location=Office&value1=24.75&value2=49.54&value3=1005.14";
// Send HTTP POST request
int httpResponseCode = http.POST(httpRequestData);
// If you need an HTTP request with a content type: text/plain
//http.addHeader("Content-Type", "text/plain");
//int httpResponseCode = http.POST("Hello, World!");
// If you need an HTTP request with a content type: application/json, use the following:
//http.addHeader("Content-Type", "application/json");
//int httpResponseCode = http.POST("{\"value1\":\"19\",\"value2\":\"67\",\"value3\":\"78\"}");
if (httpResponseCode>0) {
Serial.print("HTTP Response code: ");
Serial.println(httpResponseCode);
}
else {
Serial.print("Error code: ");
Serial.println(httpResponseCode);
}
// Free resources
http.end();
}
else {
Serial.println("WiFi Disconnected");
}
//Send an HTTP POST request every 30 seconds
delay(30000);
}
and the php file:
<?php
$servername = "localhost";
// REPLACE with your Database name
$dbname = "sensordata";
// REPLACE with Database user
$username = "root";
// REPLACE with Database user password
$password = "";
$api_key_value = "tPmAT5Ab3j7F9";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = "SELECT id, sensor, location, value1, value2, value3, reading_time FROM SensorData";
echo '<table cellspacing="5" cellpadding="5">
<tr>
<td>ID</td>
<td>Sensor</td>
<td>Location</td>
<td>Value 1</td>
<td>Value 2</td>
<td>Value 3</td>
<td>Timestamp</td>
</tr>';
if ($result = $conn->query($sql)) {
while ($row = $result->fetch_assoc()) {
$row_id = $row["id"];
$row_sensor = $row["sensor"];
$row_location = $row["location"];
$row_value1 = $row["value1"];
$row_value2 = $row["value2"];
$row_value3 = $row["value3"];
$row_reading_time = $row["reading_time"];
// Uncomment to set timezone to - 1 hour (you can change 1 to any number)
//$row_reading_time = date("Y-m-d H:i:s", strtotime("$row_reading_time - 1 hours"));
// Uncomment to set timezone to + 4 hours (you can change 4 to any number)
//$row_reading_time = date("Y-m-d H:i:s", strtotime("$row_reading_time + 4 hours"));
echo '<tr>
<td>' . $row_id . '</td>
<td>' . $row_sensor . '</td>
<td>' . $row_location . '</td>
<td>' . $row_value1 . '</td>
<td>' . $row_value2 . '</td>
<td>' . $row_value3 . '</td>
<td>' . $row_reading_time . '</td>
</tr>';
}
$result->free();
}
$conn->close();
?>
</table>
</body>
</html>