ESP-32 CAM not sending get/Post parameter

[redson11]

Hello,

first of all i have my arduino that is connected via Wifi with my Web Server.
The Arduino is used as a recylingcenter, and should give me a value of the Scale.

But somehow the Get/Post Parameter from my .PHP file that im using to retrieve the data, isnt sending it and it always says Undefined array key in my WebServer when i look under error.log.

Arduino.ino

`#include "SSD1306Wire.h"
#include "HX711.h"
#include <ESP32QRCodeReader.h>
#include <WiFi.h>
#include <HTTPClient.h>
#include <Bounce2.h>

//Debounce switch
#define BUTTON_PIN 12
Bounce2::Button button = Bounce2::Button();

//Scheduler
#include <TaskScheduler.h>

//**************** Defining variables and constants ************

// I/O
#define OUT1 16
#define IN1 12
#define FLASHLIGHT 4

// OLED Display
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define I2C_SDA 13
#define I2C_SCL 15
#define OLED_ADDR 0x3C
SSD1306Wire display(OLED_ADDR, I2C_SDA, I2C_SCL);

// QR
ESP32QRCodeReader reader(CAMERA_MODEL_AI_THINKER);
struct QRCodeData qrCodeData;
String Payload = "NULL";

//Weighting
#define HX711_SCK 14
#define HX711_DOUT 2
HX711 SCALE;
int new_weight = 0;
int old_weight = -1;
int MEASURE = 0;
//linear equation f(x)=ax+b (set first values to one (a=1, b=0))
int scale_scale = 811; //=a (515)
int scale_offset = 4420; // =-b (2)

//ID of balance
String idBalance = "11";
String state = "Scanning";
// WIFI
const char *ssid = "INSEL"; //REPLACE_WITH_YOUR_SSID
const char *password = "nootherperson"; //REPLACE_WITH_YOUR_PASSWORD
WiFiClient espClient;

//Your Domain name with URL path or IP address with path
String host = "http://172.17.248.90";
String file_to_access = "/includes/ReceivingScript.php";
String URL = host + file_to_access;

//Scheduler
Scheduler ts;
void switchStatus();
void onQrCodeTask();

// Tasks
// Task taskSwitch runs every 50 milliseconds forever and adding task to the chain on creation
Task taskSwitch(50, TASK_FOREVER, &switchStatus, &ts, true);
Task taskQR(100, TASK_FOREVER, &onQrCodeTask, &ts, true);

//************************************************** Basic functions ********************************************
//Function to show 3 lines (given as parameters) on the OLED display
void showOLEDMessage(String line1, String line2, String line3) {
display.init(); // clears screen
display.flipScreenVertically();
display.setFont(ArialMT_Plain_16);
display.drawString(0, 0, line1); // adds to buffer
display.drawString(0, 20, line2);
display.drawString(0, 40, line3);
display.display(); // displays content in buffer
}

//Function to connect to WIFI
void wifi_connect() {
Serial.print("Connecting to ");
Serial.println(ssid);
WiFi.begin(ssid, password);
Serial.print("Attempting to connect");
while (WiFi.status() != WL_CONNECTED) {
delay(500);
showOLEDMessage("Connecting", "...", "");
}
showOLEDMessage("WIFI", "connected", "");
delay(1000);
}

//Function initialising and calibrating the scale
void SCALE_INIT() {
SCALE.begin(HX711_DOUT, HX711_SCK);
SCALE.power_down();
SCALE.power_up();
while (SCALE.is_ready() != 1) {
//HX711 not found
}
//HX711 ready!
SCALE.set_scale(scale_scale);
SCALE.set_offset(scale_offset);
SCALE.tare();
}

//Function to get the measurement of the weight
int SCALE_GET() {
new_weight = SCALE.get_units(10);
if (new_weight != old_weight) {
return (new_weight);
}
}

//************************************************** Checking status of switch ********************************************
//Function to check the status of the switch and trigger the according action
void switchStatus() {
button.update();
if (button.pressed()){
//based on the current state start QR-code or measuring of weight
if (state == "Scanning" && Payload == "NULL" && !taskQR.isEnabled()) {
showOLEDMessage("Reading", "QR", "Code");
reader.beginOnCore(1);
taskQR.enable();
taskSwitch.abort();
} else if (state == "Measuring" && !taskQR.isEnabled()) {
startWeighting();
}
}
}

//************************************************** Start weighting process *******************************************
void startWeighting() {
MEASURE = SCALE_GET(); //get the measurement
if (MEASURE != 0) {
showOLEDMessage("2. Weight:", String(MEASURE), "g");
delay(1000);
// Transfer data
showOLEDMessage("3. Transfer", "QR " + Payload, String(MEASURE) + " g");
delay(2000);
String response = httpGETConfirm(Payload, String(MEASURE));
Serial.println("Response from server: " + response); // Debugging output
showOLEDMessage("4. Remove", "your", "trash!");
Payload = "NULL";
state = "Scanning";
delay(2000);
showOLEDMessage("1. Press switch", "to start reading", "QR-code");
} else {
showOLEDMessage("No trash measured", "1.Put your Trash", "2.Press switch");
}
}

//************************************************** QR Code Scanner ********************************************
void onQrCodeTask() {
taskSwitch.disable();
struct QRCodeData qrCodeData;
if (reader.receiveQrCode(&qrCodeData, 100) && qrCodeData.valid) {
Payload = ((const char *)qrCodeData.payload);
if (Payload != "NULL") {
reader.end();
taskQR.disable();
//check if access granted
if (httpGETAuthentication(Payload) == "access granted") {
SCALE_INIT();
state = "Measuring";
showOLEDMessage("Access granted", "for", Payload);
delay(2000);
showOLEDMessage(Payload, "1.Put your Trash", "2.Press switch");
} else {
state = "Scanning";
Payload = "NULL";
showOLEDMessage("Access denied", "press Switch", "to read again");
}
}
}
taskSwitch.enable();
}

//************************************************** Communication with server ********************************************
//Function sending a request with the measured weight and QR code to the server and receive an answer
String httpGETConfirm(String pQR, String pWeight) {
String status = "";
//Check WiFi connection status
if (WiFi.status() == WL_CONNECTED) {
HTTPClient http;
String url = URL + "?QRCodeMeasure=" + pQR + "&hostname=" + idBalance + "&measuredValue=" + pWeight;
http.begin(url); // Specify the target URL

// Send the GET request
int httpResponseCode = http.GET();

//save the HTTP response from the server.
if (httpResponseCode > 0) {
  //HTTP response code:
  String payload_response = http.getString();
  status = payload_response;
} else {
  status = "Error code: " + String(httpResponseCode);
}
// Free resources
http.end();

} else {
status = "WiFi Disconnected";
}
showOLEDMessage("Server reply:", status, "");
delay(1000);
return status;
}

//Function sending a request to the server and getting the user authenticated based on the QR code
//Reply from server: access granted or access denied
String httpGETAuthentication(String pQR) {
String status = "";
//Check WiFi connection status
if (WiFi.status() == WL_CONNECTED) {
HTTPClient http;
String url = URL + "?QRCodeAuthenticate=" + pQR;
http.begin(url); // Specify the target URL

// Send the GET request
int httpResponseCode = http.GET();

//save the HTTP response from the server.
if (httpResponseCode > 0) {
  //HTTP response code:
  String payload_response = http.getString();
  status = payload_response;
} else {
  status = "Error code: " + String(httpResponseCode);
}
http.end(); // Free resources

} else {
status = "WiFi Disconnected";
}
showOLEDMessage("Server reply:", status, "");
return status;
}

void setup() {
// put your setup code here, to run once:
Serial.begin(115200);
pinMode(FLASHLIGHT, OUTPUT);
//Debounce the switch
button.attach(BUTTON_PIN, INPUT);
// Debounce interval in milliseconds
button.interval(5);
// Indicate that the low state corresponds to physically pressing the switch
button.setPressedState(LOW);
//Flashing light when starting up
digitalWrite(FLASHLIGHT, HIGH);
delay(100);
digitalWrite(FLASHLIGHT, LOW);
taskQR.disable();
showOLEDMessage("", "Startup", "");
delay(1000);
wifi_connect();
reader.setup();
showOLEDMessage("Press switch", "to start reading", "QR-code");
}

void loop() {
// put your main code here, to run repeatedly:
ts.execute();
}
`
ReceivingScript.php

`<?php
$dbc = f_db_connect();

// Check if connection was successful
if ($dbc->connect_error) {
die("Connection failed: " . $dbc->connect_error);
}

// Initialize variables
$access = "";
$QRCodeMeasure = $_GET['QRCodeMeasure'] ?? ''; // Get the QR code measure from the GET request
$hostname = $_GET['hostname'] ?? ''; // Get the hostname from the GET request
$value = $_GET['measuredValue'] ?? ''; // Get the measured value from the GET request

// Check if any required parameter is empty
if (empty($QRCodeMeasure) || empty($hostname) || empty($value)) {
die("Missing parameters in the request.");
}

// Check if the QR code is authorized
$queryCheckAccess = "SELECT * FROM tblBenutzer WHERE dtRandomCode = '$QRCodeMeasure'";
$resultCheckAccess = $dbc->query($queryCheckAccess);

if ($resultCheckAccess->num_rows > 0) {
echo "access granted";
$access = "granted";
} else {
echo "Access denied: QR code not authorized.";
$access = "denied";
}

// If access is granted, insert data into the database
if ($access == "granted") {
// Get the current timestamp
date_default_timezone_set('UTC');
$time = date('Y-m-d H:i:s');

// Insert data into the database
$sql = "INSERT INTO tblAbfall (idAbfall, dtGewicht, dtDatum, fiAbfallTyp, fiRechnung, fiMessstation, fiBenutzer)
        VALUES (NULL, '$value', '$time', 'PLA', 2, 2, '$hostname')";

// Execute the SQL query
if ($dbc->query($sql) === TRUE) {
    echo "Data inserted successfully.";
} else {
    echo "Error: " . $sql . "<br>" . $dbc->error;
}

}

// Close the database connection
$dbc->close();
?>`

Error.log

[pert]

I moved your topic to an appropriate forum category @redson11.

In the future, please take some time to pick the forum category that best suits the subject of your topic. There is an "About the _____ category" topic at the top of each category that explains its purpose.

This is an important part of responsible forum usage, as explained in the "How to get the best out of this forum" guide. The guide contains a lot of other useful information. Please read it.

Thanks in advance for your cooperation.