ESP32 - 如何在连接到 AWS IoT Core 的实用程序文件中制作 PubSubClient function

Question

I want to make a function that uses PubSubClient and WifiClientSecure to connect to AWS MQTT broker, and I want to define it in a separate file so I can reuse it, but the ESP32 is crashing every time the code runs.

I want to reuse this function I found in this tutorial in a iot_utils.cpp file, instead of definining it in the main file. When i define it in the main file, it works fine, but thats not what i want to do.

This is the function in the tutorial :

WiFiClientSecure net = WiFiClientSecure();
PubSubClient client(net);
 
void connectAWS()
{
    WiFi.mode(WIFI_STA);
    WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
    Serial.println("Connecting to Wi-Fi");
    while (WiFi.status() != WL_CONNECTED) {
        delay(500);
        Serial.print(".");
    }
    // Configure WiFiClientSecure to use the AWS IoT device credentials
    net.setCACert(AWS_CERT_CA);
    net.setCertificate(AWS_CERT_CRT);
    net.setPrivateKey(AWS_CERT_PRIVATE);
    // Connect to the MQTT broker on the AWS endpoint we defined earlier
    client.setServer(AWS_IOT_ENDPOINT, 8883);
    // Create a message handler
    client.setCallback(messageHandler);
    Serial.println("Connecting to AWS IOT");
    while (!client.connect(THINGNAME)) {
        Serial.print(".");
        delay(100);
    }
    if (!client.connected()) {
        Serial.println("AWS IoT Timeout!");
        return;
    }
    // Subscribe to a topic
    client.subscribe(AWS_IOT_SUBSCRIBE_TOPIC);
    Serial.println("AWS IoT Connected!");
}

I dont want to use it in the main file, instead, i want to put it in a separate file. To do this, i made the corresponding header and src file, and in the iot_utils.cpp file I defined the function like this:

void connectAWS(WiFiClientSecure& net, PubSubClient& client, const char* topic) {
   // the code here...
}

But when in my main file, I call it like this:

   WiFiClientSecure net = WiFiClientSecure();
   PubSubClient client(net);

void setup() {
   connectAWS(net, client, "esp32/pub");
}

The ESP32 crashes with the following information:

ets Jun  8 2016 00:22:57

rst:0xc (SW_CPU_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:2
load:0x3fff0030,len:1184
load:0x40078000,len:13132
load:0x40080400,len:3036
entry 0x400805e4
Connecting to Wi-Fi
.Connecting to AWS IOT
Guru Meditation Error: Core  1 panic'ed (LoadProhibited). Exception was unhandled.

Core  1 register dump:
PC      : 0x4015b50c  PS      : 0x00060f30  A0      : 0x800d3bba  A1      : 0x3ffb26f0  
A2      : 0x3ffc2c74  A3      : 0x3f4050f9  A4      : 0x00000015  A5      : 0x0000ff00  
A6      : 0x00ff0000  A7      : 0xff000000  A8      : 0x800d78a6  A9      : 0x3ffb2700  
A10     : 0x000003e8  A11     : 0x3f4050f9  A12     : 0x00000002  A13     : 0x0000ff00  
A14     : 0x00ff0000  A15     : 0xff000000  SAR     : 0x00000017  EXCCAUSE: 0x0000001c  
EXCVADDR: 0x000003e8  LBEG    : 0x40089729  LEND    : 0x40089739  LCOUNT  : 0xfffffffa  


Backtrace:0x4015b509:0x3ffb26f00x400d3bb7:0x3ffb2710 0x400d3de2:0x3ffb2750 0x400d3915:0x3ffb2780 0x400d3819:0x3ffb27a0 0x400d877e:0x3ffb2820 

What am I doing wrong? I just want to reuse the connectAWS in other files, so i dont have to copy-paste it every time

Answer 1

I realized how to do it, and it is declaring net and client in the iot_utils.hpp header file, and defining them in iot_utils.cpp source file, just like this:

iot_utils.hpp

#ifndef iot_utils
#define iot_utils
#include "WiFi.h"
#include <ArduinoJson.h>
#include <PubSubClient.h>
#include <WiFiClientSecure.h>
// The reason why net and client are both in the header and in the source: https://stackoverflow.com/questions/74729454/platformio-c-multiple-multiple-definition-of
extern WiFiClientSecure net;
extern PubSubClient client;
void connectAWS();
#endif

iot_utils.cpp

#include "iot_utils.hpp"
#include "leds_secrets.h"
// The reason why net and client are both in the header and in the source: https://stackoverflow.com/questions/74729454/platformio-c-multiple-multiple-definition-of
WiFiClientSecure net = WiFiClientSecure();
PubSubClient client(net);
void connectAWS()
{
    (...)
}

And then just including "iot_utils.hpp" in my main file