B4R Question ESP32 connected to Node-RED, but it can't receive a topic message input from the server

[irhamnur00]

I was just trying to make my first project with B4R. Also, I was a newbie in microcontroller programming.

In this my first project, I make a dashboard in Node-RED to display a value from the ESP32 and to control the blue LED on ESP32. The value had been successfully sent, but until now the topic message for turning on the LED from the server can't be received. These several days, I was looking for a way to receive a topic message from Node-RED server. I had to edit Mqtt_MessageArrived which I think that a function duty to receive a topic message from the server, but I'm not found any solution on the internet.

Below is my program code:

Sub Process_Globals
    Public Serial1 As Serial
    Private wifi As ESP8266WiFi
    Private mqtt As MqttClient
    Private wifiClient As WiFiSocket
    Private ServerIP() As Byte = Array As Byte(000, 000, 000, 000)
    Private const ServerPort As UInt = 1883
    Private const pinBiru As Byte = 0x02
    Private D2 As Pin
    Private LEDbiru As String = "esp-irham/LEDbiru"
End Sub


Sub Connect(unused As Byte)
    If mqtt.Connect = False Then
        Log("trying to connect again")
        CallSubPlus("Connect", 1000, 0)
        Return
    End If
    Log("Connected to broker")
    mqtt.Subscribe("esp32", 0)
    mqtt.Publish2("pc", Array As Byte(1, 2, 3), True)
    If mqtt.Subscribe(LEDbiru, 0) Then
        Log("subscribed")
    End If
End Sub

Sub Mqtt_MessageArrived (Topic As String, Payload() As Byte)
    Dim bc As ByteConverter
    Dim PayLoadStr As String = bc.StringFromBytes(Payload)
    Log(PayLoadStr)
    Log("Message arrived. Topic=", Topic, " payload: ", Payload)
    'Take action. Mengeset dan Memilih topic yang masuk
    Select Topic
        Case LEDbiru
            If PayLoadStr = "on" Then
                Log("On")
                D2.DigitalWrite(True)
            Else
                Log("Off")
                D2.DigitalWrite(False)
            End If
    End Select
End Sub

Sub Mqtt_Disconnected
    Log("Disconnected")
    mqtt.Close
    Connect(0)
End Sub

Sub WifiConnect
    If wifi.Connect2("SSID", "wifipass") Then
        Log("Connected to network")
    Else
        Log("Failed to connect to network. Trying to reconnect")
        'CallSubPlus("WifiConnect", 1000, 0)
        'Return
    End If
End Sub

Private Sub AppStart
    Serial1.Initialize(115200)
    D2.Initialize(pinBiru, D2.MODE_OUTPUT)
    Log("AppStart")
    
    'Wifi connection function
    WifiConnect
    
    mqtt.Initialize(wifiClient.Stream, ServerIP, ServerPort, "esp-irham", "Mqtt_MessageArrived", "Mqtt_Disconnected")
    
    'MQTT connection functions
    Connect(0)
    
    Dim Nilai() As Byte = "1 "
    If mqtt.Publish2("tes-tulisan", Nilai, True) Then
        Log("Sent Successfully")
    End If
    
        Dim Angka() As Byte = "3" 'Array As Byte(7)
    If mqtt.Publish2("tes-angka", Angka, True) Then
        Log("2nd Sent Successfully")
    End If
    'Sleep(5000)
    'D2.DigitalWrite(True)
End Sub

Below is my Node-Red Flow:

 

[janderkan]

Did you remember to subscribe to the message that you want to receive?

 

[irhamnur00]

Did you remember to subscribe to the message that you want to receive?

I set it at 23rd line

 

[viriato]

Hello,
I think you should use "esp-irham/LEDbiru/#"

Bye