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Smart home application with the T-Watch 2020 V3 from Lilygo

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One method of connecting smart home modules to each other is to use a local WiFi network with the UDP protocol.
For example, Wiz devices can be addressed in this way.
Below, we will show you how to send on/off commands to a smart home lamp using the T-WATCH.
The necessary UDP messages were found here:

https://seanmcnally.net/wiz-config.html

Turn on the light or power outlet:
{"id":1,"method":"setState","params":{"state":true}}

Turn off the light or unplug the power outlet:
{"id":1,"method":"setState","params":{"state":false}}

Set the lamp to a specific light temperature (here 3000 Kelvin) and a specific brightness (here 75 percent):
{"id":1,"method":"setPilot","params":{"temp":3000,"dimming":75}}

Set the red/green/blue ratio to a specific ratio and brightness:
{"id":1,"method":"setPilot","params":{"r":255,"g":0,"b":0,"dimming": 75}}

Status query for a device:
{"method":"getPilot","params":{}}

Code 0-1: UDP messages required for simple control tasks for products from Wiz.

For more information on smart home technology, see also:

12_Technikphilosophie/05_Fallstudien/01_Smart_Home

Bertko, C., Weber, T., Home Smart Home - Der praktische Einstieg in die Hausautomation, Hanser, München 2017.
Butz, A., Krüger, A., Mensch-Maschine-Interaktion, de Gruyter, Berlin 2017.
Sadek, I. et. al., Novel Unobtrusive Approach for Sleep Monitoring Using Fiber Optics in an Ambient Assisted Living Platform, S.48-60 in: Enhanced Quality of Life and Smart Living, Springer LNCS 10461, Cham 2017.
Seiderer, A., Dang, C.T., André, E., Exploring Opportunistic Ambient Notifications in the Smart Home to Enhance Quality of Live, S.151-160 in: Enhanced Quality of Life and Smart Living, Springer LNCS 10461, Cham 2017.
Treviranus, J., Teaching Our Machines to be Smart, Not Prejudiced, S.XIII in: Enhanced Quality of Life and Smart Living, Springer LNCS 10461, Cham 2017.

Preliminary test: Use of a Java/Processing sketch on a laptop/PC

Bild 0-1: Control the lamp from your PC.

https://youtu.be/Ht2dDGhvP4o -- Control the lamp from your PC, video.

Pressing the button alternately sends the switch-on and switch-off message to the lamp.
See in particular the callback method keyPressed()...
A hotspot was set up directly with the laptop.
The broadcast IP (here 10.42.0.255) must be determined from the respective hotspot network.
The port address is fixed and corresponds to the one accepted by the lamp, here 38899.

import hypermedia.net.*;

UDP udp; 

void setup() 
{
  udp = new UDP( this, 38899 );
  udp.listen( true );
}

void draw() 
{
    size(200,200);
    background(255,255,255);
}
 
boolean AN = true;
void keyPressed() 
{  
    AN=!AN;
    String message  = "";
    if(AN)
      message = "{\"id\":1,\"method\":\"setState\",\"params\":{\"state\":true}}";
    else  
      message = "{\"id\":1,\"method\":\"setState\",\"params\":{\"state\":false}}";
    String ip       = "10.42.0.255";  // the remote IP address
    int port        = 38899;		  // the destination port
    
    message = message+";\n";
    udp.send( message, ip, port );
    
}
void receive( byte[] data, String ip, int port ) 
{  
  data = subset(data, 0, data.length-2);
  String message = new String( data );  
  println( "receive: \""+message+"\" from "+ip+" on port "+port );
}

Code 0-2: TWATCH_WIZ002_PC -- Java/Processing-Sketch zur Steuerung einer Smart Home Lampe per Tastendruck.

TWATCH_WIZ002_PC.zip -- Java/Processing sketch for controlling a smart home lamp at the touch of a button.

Using a T-WATCH V3 to control a smart home lamp

The hotspot hotspotK continued to be provided by the laptop.
Alternatively, a smartphone could be used to create the hotspot.
The name of the hotspot and the WPA2 password must be adjusted in the following source code.
If more than one lamp or socket is in use, the variable id in the sent message must be varied.
Once again, the TWATCH_PROC023 project serves as the basis and must be copied using "Save as".
Then only the main tab is changed.
Due to data type compatibility issues, all messages were provided twice: as const uint8_t to send them and as char to measure their length with strlen(...).

08_Archiv/06_Ing/01_Bauplan/04_Hotspot -- Instructions for setting up a hotspot on a Linux PC (Xubuntu).

05_esp32AV/01_Bauanleitung/01_Elektronik_und_Software/03_Videostream -- Instructions for setting up a hotspot with an Android smartphone.

At the touch of a button, the switch-on and switch-off messages are sent alternately via UDP.
If the WiFi connection is not yet established when the button is pressed, an attempt is made to renew it first.
The display shows whether the lamp is currently on or off.

Bild 0-2: Lamp off.

Bild 0-3: Lamp on.

https://youtu.be/KKv1UixNgjY -- Controlling a Wiz smart home lamp using a LilyGo T-WATCH V3, video.

TWATCH_PROC023_WIZ_LAMP_SMARTHOME.zip -- Project for Arduino IDE.

#include "twatch.h"
#include "variables.h"
#include "functions.h"

const char* hotspot = "hotspotK";
const char* password = "12345678";
int udpport = 38899;


bool ON=false;

const uint8_t messageON[] = "{\"id\":1,\"method\":\"setState\",\"params\":{\"state\":true}}";
const uint8_t messageOFF[] = "{\"id\":1,\"method\":\"setState\",\"params\":{\"state\":false}}";
char messageON_LEN[] = "{\"id\":1,\"method\":\"setState\",\"params\":{\"state\":true}}";
char messageOFF_LEN[] = "{\"id\":1,\"method\":\"setState\",\"params\":{\"state\":false}}";
char ip[] = "10.42.0.255";
IPAddress serverIP(10, 42, 0, 255); // Replace with the server's IP address
uint16_t serverPort = 38899; // Replace with the server's port
void setup() 
{
    setupTWATCH();
    setupWIFI(hotspot,password,udpport);
    setFont(1, 255,255,255,  0,0,0);
    backlight(true); 
}

void loop() 
{
  if(button())
  {
      if(!WIFIOKAY)
         setupWIFI(hotspot,password,udpport);
      ON=!ON;   
      if(ON)
      {
           udp.writeTo(messageON,strlen(messageON_LEN),serverIP,serverPort);
      }
      else
      {
           udp.writeTo(messageOFF,strlen(messageOFF_LEN),serverIP,serverPort);        
      }
      
  }
  clear();
  cursor(0,0);
  if(ON)
     editor("LAMP ON!");
  else
     editor("LAMP OFF!");
     
  delay(100);  

}

Code 0-3: Main tab in project TWATCH_PROC023_WIZ_LAMP_SMARTHOME.