Simple subscribe_json call raises a compiler error

ESPHome
1

Hi,

I am experiencing a problem when compiling the code below.
This code is only to test MQTT and JSON functionality before developing the actual functionality.

Here comes the compiler-error:

src/mqtt_pulse_switch.h:18:88: error: no matching function for call to 'MqttPulseSwitch::subscribe_json(const char [32], void (MqttPulseSwitch::*)(ArduinoJson::JsonObject&))'

What I don’t understand is that I am using the function call “subscribe_json” direcly from the example in the documentation. I looked in the API, but as I am not that experienced in C, I did not come closer to understanding the problem.
Can anyone help, please?

Thanks

class MqttPulseSwitch : public Component, public CustomMQTTDevice {
 public:
  int string_id = 0;    //varmestreng 1 til 5
  int dutycycle = 20;   //percentage_pn
  int interval = 120;   //minutes - 0=off
  int switch_pin = 27;  //switch output pin
  int target_temp = 21; //måltemperatur
  
  void setup() override {
    pinMode(27, OUTPUT);
    bool state;
    subscribe("vvv46/heating/floor/unit/measured/", &MqttPulseSwitch::on_message);
    subscribe_json("vvv46/heating/floor/unit/setup/", &MqttPulseSwitch::on_json_message);
    publish("vvv46/heating/floor/unit/availability/", "online");
  }

  void on_message(const std::string &payload) {
    float payloadAsFloat = std::stof(payload);
    
    if (payloadAsFloat < target_temp) {
      digitalWrite(27, HIGH);
      publish("vvv46/heating/floor/unit/3/", 1);
    } else {
      digitalWrite(27, LOW);
      publish("vvv46/heating/floor/unit/3/", 0);
    }
  }
   void on_json_message(JsonObject &root) {
    if (!root.containsKey("string_id"))
      return;
    int string_id = root["string_id"];
    if (root["string_id"] = 3) { 
      //streng 3 - køkkenvarme
      dutycycle = root["dutycycle"];
      interval = root["interval"];
      switch_pin = root["switch_pin"];
      target_temp = root["target_temp"];
      dutycycle = root["dutycycle"];
    }
    publish_json("vvv46/heating/floor/unit/received/", [=](JsonObject &root2) {
      root2["message"] = "JSON received";
      root2["string_id"] = string_id;
      root2["dutycycle"] = dutycycle;
      root2["interval"] = interval;
      root2["switch_pin"] = switch_pin;
      root2["target_temp"] = target_temp;
    });
  } 
};
2

You posted in the esphome section, but you don’t appear to be using esphome.

If you are, please point to those documents you say you copied.

3

I’m guessing you mean this example?

https://esphome.io/custom/custom_component.html#mqtt-custom-component

Assuming you have also included the #include, maybe this post will help:

4

So apparently someone found a documentation error last year and hasn’t bothered to fix it. #sigh#

5

Indeed, this is the documentation I copied.
Thanks a lot. I will try to correct according to you reply.

6

And it works.
Thanks

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