Problem with memcpy function

Projects Programming
1

Hi everyone
I am bulding some sort of weather station but Ihave problems with sending the data from my reciever (I am using esp-now network) to the server and I cant open my server in my web brower.

I am using

  • esp 32 as a server
  • esp8266 as a sender
  • dht11 as the sensors
  • arduino 2.3.4

Here is my code for the esp 8266 (Its big mix of codes I found online so its may be bit weird)

#include <ESP8266WiFi.h>
#include <espnow.h>
#include "DHT.h"
#define DHTPIN 2 

#define DHTTYPE DHT11

DHT dht(DHTPIN, DHTTYPE);

#define CHANNEL 4
float tempe;
float humi;
int reading;
uint8_t remoteMac[] = {0xfc, 0xb4, 0x67, 0xf1, 0x47, 0x58};

struct __attribute__((packed)) DataStruct {
    //char text[32];
    float hum;
    float temp;
    int read;
};

DataStruct myData;

unsigned long lastSentMillis;
unsigned long sendIntervalMillis = 1000;

void InitESPNow() {
  WiFi.disconnect();
  if (esp_now_init()==0) {
    Serial.println("ESPNow Init Success");
  }
  else {
    Serial.println("ESPNow Init Failed");
    ESP.restart();
  }
}


void sendData() {
  if (millis() - lastSentMillis >= sendIntervalMillis) {
        lastSentMillis += sendIntervalMillis;
        reading = reading + 1;
        myData.read = reading;
        esp_now_send(NULL, (uint8_t *)&myData, sizeof(myData)); 
        Serial.println("sent data");
        Serial.println(myData.hum);
        Serial.println(myData.temp);
    }
}

void setup() {
    
  Serial.begin(74880); Serial.println();
    dht.begin();
    reading = 0;
    Serial.println("Starting dht");

    WiFi.mode(WIFI_STA); 
    WiFi.disconnect();

    Serial.printf("This mac: %s, ", WiFi.macAddress().c_str());
    Serial.printf("slave mac: %02x%02x%02x%02x%02x%02x", remoteMac[0], remoteMac[1], remoteMac[2], remoteMac[3], remoteMac[4], remoteMac[5]);

    Serial.printf(", channel: %i\n",CHANNEL);
    InitESPNow();
    esp_now_set_self_role(ESP_NOW_ROLE_CONTROLLER);
    esp_now_add_peer(remoteMac, ESP_NOW_ROLE_SLAVE, CHANNEL, NULL, 0);
    }

void loop() {
  humi = dht.readHumidity();
  tempe = dht.readTemperature();
  if (isnan(humi) || isnan(tempe)) {
    Serial.print("failed to read ");
  } else {
    if (myData.hum != humi) {
      myData.hum = humi;
      myData.temp = tempe;
      sendData();
    } else if (myData.temp != tempe) {
      myData.hum = humi;
      myData.temp = tempe;
      sendData();
    }
  }
  delay(1000);
}

here is the output

13:35:01.820 -> Packet received from: ea:c2:fb:3f:e4:c2
13:35:01.820 -> 44.00
13:35:01.820 -> 20.50
13:35:01.820 -> 135
13:35:01.820 -> event send :{"id":1,"temperature":0,"humidity":0,"readingId":0}

here is the code for the esp32

/*********
  Rui Santos & Sara Santos - Random Nerd Tutorials
  Complete project details at https://RandomNerdTutorials.com/esp-now-many-to-one-esp32/
  Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files.  
  The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
*********/
#include <esp_now.h>
#include <WiFi.h>
#include "ESPAsyncWebServer.h"
#include "AsyncTCP.h"
#include <ArduinoJson.h>
//my structure
struct __attribute__((packed)) DataStruct {
    //char text[32];
    float hum;
    float temp;
    int read;
};
DataStruct myData;
const char* ssid = "Popo";
const char* password = "81popelakova";
int chan;
//setings fo webserver
AsyncWebServer server(80);
AsyncEventSource events("/events");

//web server
const char index_html[] PROGMEM = R"rawliteral(
<!DOCTYPE HTML><html>
<head>
  <title>ESP-NOW DASHBOARD</title>
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.7.2/css/all.css" integrity="sha384-fnmOCqbTlWIlj8LyTjo7mOUStjsKC4pOpQbqyi7RrhN7udi9RwhKkMHpvLbHG9Sr" crossorigin="anonymous">
  <link rel="icon" href="data:,">
  <style>
    html {font-family: Arial; display: inline-block; text-align: center;}
    p {  font-size: 1.2rem;}
    body {  margin: 0;}
    .topnav { overflow: hidden; background-color: #2f4468; color: white; font-size: 1.7rem; }
    .content { padding: 20px; }
    .card { background-color: white; box-shadow: 2px 2px 12px 1px rgba(140,140,140,.5); }
    .cards { max-width: 700px; margin: 0 auto; display: grid; grid-gap: 2rem; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); }
    .reading { font-size: 2.8rem; }
    .packet { color: #bebebe; }
    .card.temperature { color: #fd7e14; }
    .card.humidity { color: #1b78e2; }
  </style>
</head>
<body>
  <div class="topnav">
    <h3>ESP-NOW DASHBOARD</h3>
  </div>
  <div class="content">
    <div class="cards">
      <div class="card temperature">
        <h4><i class="fas fa-thermometer-half"></i> BOARD #1 - TEMPERATURE</h4><p><span class="reading"><span id="t1"></span> &deg;C</span></p><p class="packet">Reading ID: <span id="rt1"></span></p>
      </div>
      <div class="card humidity">
        <h4><i class="fas fa-tint"></i> BOARD #1 - HUMIDITY</h4><p><span class="reading"><span id="h1"></span> &percnt;</span></p><p class="packet">Reading ID: <span id="rh1"></span></p>
      </div>
      <div class="card temperature">
        <h4><i class="fas fa-thermometer-half"></i> BOARD #2 - TEMPERATURE</h4><p><span class="reading"><span id="t2"></span> &deg;C</span></p><p class="packet">Reading ID: <span id="rt2"></span></p>
      </div>
      <div class="card humidity">
        <h4><i class="fas fa-tint"></i> BOARD #2 - HUMIDITY</h4><p><span class="reading"><span id="h2"></span> &percnt;</span></p><p class="packet">Reading ID: <span id="rh2"></span></p>
      </div>
    </div>
  </div>
<script>
if (!!window.EventSource) {
 var source = new EventSource('/events');
 
 source.addEventListener('open', function(e) {
  console.log("Events Connected");
 }, false);
 source.addEventListener('error', function(e) {
  if (e.target.readyState != EventSource.OPEN) {
    console.log("Events Disconnected");
  }
 }, false);
 
 source.addEventListener('message', function(e) {
  console.log("message", e.data);
 }, false);
 
 source.addEventListener('new_readings', function(e) {
  console.log("new_readings", e.data);
  var obj = JSON.parse(e.data);
  document.getElementById("t"+obj.id).innerHTML = obj.temperature.toFixed(2);
  document.getElementById("h"+obj.id).innerHTML = obj.humidity.toFixed(2);
  document.getElementById("rt"+obj.id).innerHTML = obj.readingId;
  document.getElementById("rh"+obj.id).innerHTML = obj.readingId;
 }, false);
}
</script>
</body>
</html>)rawliteral";


//when recieved
void OnDataRecv(const uint8_t * mac_addr, const uint8_t *incomingData, int len) {
  char macStr[18];
  Serial.print("Packet received from: ");
  snprintf(macStr, sizeof(macStr), "%02x:%02x:%02x:%02x:%02x:%02x",
           mac_addr[0], mac_addr[1], mac_addr[2], mac_addr[3], mac_addr[4], mac_addr[5]);
  Serial.println(macStr);
  memcpy(&myData, incomingData, sizeof(myData));
  Serial.println(myData.hum);
  Serial.println(myData.temp);
  Serial.println(myData.read);
  StaticJsonDocument<1000> root;
  String payload;                        
  root["id"] = 1;
  root["temperature"] = float(incomingData.temp);
  root["humidity"] = float(incomingData.hum);
  root["readingId"] = float(incomingData.read);
  serializeJson(root, payload);
  Serial.print("event send :");
  serializeJson(root, Serial);
  events.send(payload.c_str(), "new_readings", millis());
  Serial.println();
}
void setup() {
  Serial.begin(115200);
  WiFi.mode(WIFI_STA);
  if (esp_now_init() != ESP_OK) {
    Serial.println("Error initializing ESP-NOW");
    return;
  }
  esp_now_register_recv_cb(esp_now_recv_cb_t(OnDataRecv));
  
  chan = WiFi.channel();
  Serial.print("Station IP Address: ");
  Serial.println(WiFi.localIP());
  Serial.print("Wi-Fi Channel: ");
  Serial.println(WiFi.channel());
  //Start Web server
  server.on("/", HTTP_GET, [](AsyncWebServerRequest *request){
    request->send_P(200, "text/html", index_html);
  });
  
  events.onConnect([](AsyncEventSourceClient *client){
    if(client->lastId()){
      Serial.printf("Client reconnected! Last message ID that it got is: %u\n", client->lastId());
    }
   
    client->send("hello!", NULL, millis(), 10000);
  });
  server.addHandler(&events);
  // start server
  server.begin();
}


 
void loop() {

  static unsigned long lastEventTime = millis();
  static const unsigned long EVENT_INTERVAL_MS = 5000;
  if ((millis() - lastEventTime) > EVENT_INTERVAL_MS) {
    events.send("ping", NULL, millis());
    lastEventTime = millis(); 
  }
}

here is the output from esp8266

13:32:31.926 -> sent data
13:32:31.926 -> 44.00
13:32:31.926 -> 20.50
13:32:46.110 -> sent data
13:32:46.110 -> 45.00
13:32:46.110 -> 20.50
13:33:10.423 -> sent data
13:33:10.423 -> 44.00
13:33:10.423 -> 20.50
13:33:12.457 -> sent data
13:33:12.457 -> 45.00
13:33:12.457 -> 20.50
2

So what’s the issue?

3

The problem you outlined in the title and what you write in the message do not correspond to each other:

Have you mixed up the message?

4

Sorry I did I will change the title

5

Im sorry that i didnt write it, I cant compile it
this is what the arduino outputs

C:\Users\HP\OneDrive\Dokumenty\Arduino\esp32satckowerflow\esp32satckowerflow.ino: In function 'void OnDataRecv(const uint8_t*, const uint8_t*, int)':
C:\Users\HP\OneDrive\Dokumenty\Arduino\esp32satckowerflow\esp32satckowerflow.ino:114:44: error: request for member 'temp' in 'incomingData', which is of non-class type 'const uint8_t*' {aka 'const unsigned char*'}
  114 |   root["temperature"] = float(incomingData.temp);
      |                                            ^~~~
C:\Users\HP\OneDrive\Dokumenty\Arduino\esp32satckowerflow\esp32satckowerflow.ino:115:41: error: request for member 'hum' in 'incomingData', which is of non-class type 'const uint8_t*' {aka 'const unsigned char*'}
  115 |   root["humidity"] = float(incomingData.hum);
      |                                         ^~~
C:\Users\HP\OneDrive\Dokumenty\Arduino\esp32satckowerflow\esp32satckowerflow.ino:116:42: error: request for member 'read' in 'incomingData', which is of non-class type 'const uint8_t*' {aka 'const unsigned char*'}
  116 |   root["readingId"] = float(incomingData.read);
      |                                          ^~~~

exit status 1

Compilation error: request for member 'temp' in 'incomingData', which is of non-class type 'const uint8_t*' {aka 'const unsigned char*'}
6

You copied the data into the myData struct, why are you trying to use the struct fields on incomingData?

7

Thank you very much I cant belive that i was so dumb, i didnt use the memcpy function and copy it right away and it works, only problem is the web server (it stil doesnt show up).
Could it be that the readings come on avarege every 3 minutes?