Please help with constructor non macro use

Projects Programming
1

Dear All, I am beginner.
I am trying library HaMqttEntities.h
In an example of library, is defined macros

#define HA_DEVICE_ID   "example04"
#define HA_DEVICE_FRIENDLY_NAME "Example Numeric-Sensor HA-MQTT"

Then constructor
HADevice ha_device = HADevice(HA_DEVICE_ID,HA_DEVICE_FRIENDLY_NAME,"1.0");

But in my project, I need fill this HA_DEVICE_ID and HA_DEVICE_FRIENDLY_NAME from string, that I get from other function.

How can I put string variables to constructor?
In src library is this inputs as const char.
Thanks

2

Just use a String? ... XXX.c_str()

3

I tried that but it doesn't work.

HADevice ha_device = HADevice( exchange_data.serial_number.c_str() , exchange_data.serial_number.c_str() , exchange_data.fw_ver.c_str() );

Home Assistant will not add device. I see nonsense data in MQTT explorer.

HADevice ha_device = HADevice( "TEST" , "MYTEST" , SW_VER );

This works for a test, but is not satisfactory.

4

As long as do not say what you expect and don't say what you get it's hard to tell ...

5

Did you try to print all these strings to be sure that it contain correct data?

6

The library is saving the char* provided to it in the constructor, so you will need to ensure that the contents of the String does not change, and does not get deleted (do not use a local String that ceases to exist at the end of a function).

7

In setup, the ESP32 get some data from the second cpu Atmel ATMEGA2560.
HA MQTT is in ESP32.

string serial_number is readed from Atmega as "AH1200BL-0412133A"
string fw_ver is readed from Atmega as "1.0"

If I use c_str() in the constructor, in HA MQTT Explorer I see working sensors, but device is not added to HA devices.
In explorer, sensors has this config messages.

{"name":"WP Speed","unique_id":"rych_prac_prost","device":{"identifiers":"(��?","name":"(��?","sw_version":""},"state_topic":"homeassistant/sensor/rych_prac_prost/state","unit_of_measurement":"m/s"}

As you see, identifiers and name has mish mash

8

The strings from second cpu I have printed to console. Are right.
But, are readed later, in the setup(),
to this string variable:
exchange_data.serial_number

this variable is global and readed only once in setup

9

Well, you don't show your code, so nobody can tell what you actually do.

11

Sorry, zip is possible...
esp_comunicator.zip (1.5 MB)

ha_global.h has HA constructor

12

Sorry, I can't help. Your code is a total mess of spagetticode. grep cannot even find any of your posted constant strings like "unique_id". Clean this up, make functions instead of milelong #ifdef #endif sections, format the code.

13

Okay. Here is easy edited example from HA library.


/* ha-mqtt-entities library example of a sensor that shows
    history graph in Home Assistant.

  - Board: ESP32*

  You must set the definitions in the code under SECRETS_H.

*/
#include<Arduino.h>
#include<WiFi.h>
#include<PubSubClient.h>
#include<mat.h>

#include<HaMqttEntities.h>

// This file is not included in the repository only used for local testing
// #include "secrets.h"

// You must set the next defines
#ifndef SECRETS_H
#define WIFI_SSID "***"
#define WIFI_PASSWORD "***"
#define MQTT_SERVER "haiot.mydomain.sk"
#define MQTT_PORT 1883
#define MQTT_USER "espcom"
#define MQTT_PASSWORD "*****"
#endif

WiFiClient wifi_client;
PubSubClient mqtt_client(wifi_client);

// HA Parts
#define ENTITIES_COUNT 1
#define HA_DEVICE_ID   "example04"
#define HA_DEVICE_FRIENDLY_NAME "Example Numeric-Sensor HA-MQTT"

#define UNIT_OF_MEASUREMENT "V"
#define PRECISION 2  // Number of decimals

char *serial;
HADevice ha_device = HADevice( serial , serial , "1.0" );

HASensorNumeric ha_sensor = HASensorNumeric(
                              "sensor05uid", "Volts", ha_device, UNIT_OF_MEASUREMENT, PRECISION);

// SERIAL NUMBER
String serial_number;

void setup() {
  // for test, here is string filled
  serial_number = "AH1200BL-0412133A";
  serial = serial_number.c_str(); // **************** HERE IS COMPILE ERROR

  mqtt_client.setServer(MQTT_SERVER, MQTT_PORT);

  HAMQTT.begin(mqtt_client, ENTITIES_COUNT);
  HAMQTT.addEntity(ha_sensor);

  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
}

void loop() {
  static unsigned long one_second_delay = millis() + 1000;
  static float counter = 0;
  HAMQTT.loop();
  if (!HAMQTT.connected() &&
      !HAMQTT.connect("examples", MQTT_USER, MQTT_PASSWORD))
    delay(1000);

  if (millis() > one_second_delay) {
    // Update the sensor every second creating a sin wave
    one_second_delay = millis() + 1000;
    counter += 0.1;
    ha_sensor.setState(3.3 * sin(counter));
  }

}

Compile error
invalid conversion from 'const char*' to 'char*' [-fpermissive]

14

which line does the error refer to? .. oh I see. Make the line

char *serial ="AH1200BL-0412133A";

and

// serial_number = "AH1200BL-0412133A";
// serial = serial_number.c_str(); // **************** HERE IS COMPILE ERROR
15

has flag
// **************** HERE IS COMPILE ERROR

16

Are you understand how the string pointers works?

You call the constructor with two undefined pointers< what do you try to achieve?

17

I'm sorry, but you don't even have minimal knowledge of the subject. The serial_number is a pointer to the char. Why on earth are you trying to apply a c_str() method of String class to it?

18

I'm a beginner, so I'm looking for help. I don't have much control over pointers.
I am looking for a solution to do this.
I can't define a string firmly, I get it only in setup().

19

try this:

20

This works. But how do I add the real serial_number (as String) later in setup()?

21

Why do you need Strings if neither your text from another function nor constructor arguments are not Strings????