Category Archives: IOT / Domoticz

Computer, IOT / Domoticz

Raspberry Pi 5 Projects

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Again … out of SBCs
Where are all these things in my home. Someone is stealing Raspberry Pi’s, ESP32 and other sensors.
(Probably me)

So I’ve got multiple projects running on one RPi.

  • Dual Camera’s on top (brown ribbons), these are for VR streaming project.
  • Dual Camera’s on top. these are for a Red Light Green Light game. (Using motion detection on both camera’s for two players.
  • Below a INMP441 Mems microhone. This is a test for BirdNet recording.

All of the above are partially working. Code follows.

INMP441 is a tricky thing. I needed to do some bitbanging to get it working.

Loads of INMP441 info will be posted

IOT / Domoticz

Mqtt blinker for topic notifications

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Last year I’ve made a led pole with digital fireworks.

Giving people ability to control my Xmas lights

Time to replace for something else ..

I’ve made a mqtt 1-D game in december.

Twang with your mobile phone over the internet

I needed to change a lot to the javascript on the website to fix some stuff.

  • Fix IPhone control. (I hate iphone)
  • Fix screenlock timeout
  • Added meta refresh

The XMAS/Fireworks controller was often used, and I got notifications via my TV. (see other posts)

Now I want to see when MQTT movement when I’m in the livingroom.
So I programmed a Wemos controller to blink the internal when MQTT messages are received.

CODE:

#include <ESP8266WiFi.h>
#include <PubSubClient.h>

const char* ssid = "WIFIAP";
const char* password = "WIFIPASS";

const char* mqtt_server = "MQTTBROKER";  // MQTT broker IP
const char* mqtt_topic  = "game/tilt";

WiFiClient espClient;
PubSubClient client(espClient);

String lastPayload = "";

void setup_wifi() {
  delay(10);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
  }
}

void blinkLED() {
    digitalWrite(LED_BUILTIN, LOW);   // LED ON
    delay(200);
    digitalWrite(LED_BUILTIN, HIGH);  // LED OFF
    delay(200);
}

void callback(char* topic, byte* payload, unsigned int length) {
  String message;
  for (unsigned int i = 0; i < length; i++) {
    message += (char)payload[i];
  }

  // Blink only if topic value changed
  if (message != lastPayload) {
    blinkLED();
    lastPayload = message;
  }
}

void reconnect() {
  while (!client.connected()) {
    if (client.connect("WemosClientMqttBlink")) {
      client.subscribe(mqtt_topic);
    } else {
      delay(2000);
    }
  }
}

void setup() {
  pinMode(LED_BUILTIN, OUTPUT);
  digitalWrite(LED_BUILTIN, HIGH); 

  setup_wifi();

  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
}

void loop() {
  if (!client.connected()) {
    reconnect();
  }
  client.loop();
}
IOT / Domoticz

LoRa and more LoRa

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UPDATE : 20260126

I’ve been playing with LoRa for some time now, mostly with two adhoc LilyGO nodes.
After seeing a YT clip from Andreas Spiess I installed a meshtastic node on a Heltec V3.
Wanting more, I bought a Heltec V4 and an 8DBi (60cm) antenna.
Heltec V3 got a new home in Tyrone’s home.

GPS for the Heltec V4 module!

Via meshtastic I communicated with a guy here in the neighbourhood.
I installed Meshcore and my LoRa playground grew!

Antenna tweaking

A Nebra Helium Miner was bought, and repurposed !

There is a Raspberry CM3 in there (Compute module)
Some big antenna’s and a waterproof case.
Using POE to power the thing, the plan is to have this installation at a high point around my house. (LED pole?!? 🙂 )

Meanwhile I got these : Seeed Xiao Lora ESP32 modules

MeshTUI

My mobile Heltec V4, big antenna coming and battery operated, so I can add to https://mapme.sh

Computer, IOT / Domoticz

STM32 Nucleo-64 development board

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I’ve been playing with all kinds of MicroControllers, but not this one.

Something new to learn.

The STM32 Nucleo-64 board provides a flexible way to try out the STM32 microcontroller. The Arduino Uno V3 can be connected as a shield.

STM32 excels in high-performance, deterministic industrial control with better real-time capability, lower power, and rich peripherals, using ARM Cortex-M cores, while ESP32 dominates IoT with built-in Wi-Fi/Bluetooth, lower cost, easier Arduino/PlatformIO access, and strong community, but with higher power and less precise real-time control (Xtensa cores), making ESP32 great for connected projects and STM32 for industrial/precision tasks.

STM32 (STMicroelectronics)
Strengths:

  • Performance: Superior real-time processing, deterministic behavior, efficient for complex control.
  • Power: Advanced low-power modes, excellent for battery-powered devices.
  • Peripherals: Rich, precise analog (ADC/DAC), extensive interface options (USB, SD, LCD).
  • Reliability: Strong for industrial, medical, and automotive applications.
  • Tools: STM32CubeIDE/MX, HAL/LL libraries.

    Weaknesses:
  • Higher cost and learning curve.
  • Requires external modules for Wi-Fi/Bluetooth.

ESP32 (Espressif Systems)
Strengths:

  • Connectivity: Integrated Wi-Fi and Bluetooth (BLE).
  • Cost & Ease: Cost-effective, easy entry with Arduino IDE/PlatformIO, great for rapid prototyping.
  • Community: Strong open-source community.
  • Features: Dual-core (often), built-in OTA updates, good for audio/AI.

    Weaknesses:
  • Less deterministic/real-time performance than STM32.
  • Higher active power consumption, less precise analog.
  • Can have complex debugging/compilation.
  • When to Choose Which
  • Choose STM32 for: Industrial automation, precise instrumentation, medical devices, complex motor control, low-power wearables, general embedded systems learning.
  • Choose ESP32 for: IoT devices, smart home products, Bluetooth beacons, educational projects, rapid prototyping, audio/voice applications.
Computer, IOT / Domoticz

Fireworks LED addition and modifying Arcade buttons

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I’ve given people on the street control over my Xmas/Fireworks lights last month. (This month it is going to be converted to an interactive game)

Giving people ability to control my Xmas lights

I saw some LED strip dividers on Aliexpress, next year it’s going to have a star on top.

Like this….

Another LED related project I started today is a Whack-A-Mole game with multiple levels.
For this I need to convert a simple arcade button to a programmable multicolor version.

From single white LED to multi color, programmable.

Computer, IOT / Domoticz

Giving people ability to control my Xmas lights

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At the WHY2025 hackers event, we used bigred’s antenna pole to make a huge sign using leds.

WHY2025

It gave me the idea to make a pole which displays digital “fireworks” using leds.
Fireworks are becoming illegal the next year in the Netherlands, I think.

So why not going digital?
12 Meter pole, 300 Leds.

There is a QR code and a website link mentioned on a page at the gate.
10 presets to select via a website.

Notification on my TV

While waiting for the first visitor I made a magnetic game.
Using a bunch of magnets, and 3D printed hexagon rings.
Two players try to place magnets in a small area without moving the others. If magnets slam together, you have more pieces to place.
(Below, last player has to take those 6 pieces)

CODE for website index.html

<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>WLED Mast</title>

<style>
body {
    background: #111;
    color: #fff;
    font-family: Arial;
    margin: 0;
    padding: 20px;
    text-align: center;
}
.grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 18px;
}
button {
    padding: 25px;
    font-size: 22px;
    border-radius: 20px;
    border: none;
    background: #333;
    color: #fff;
    font-weight: bold;
}
button:active {
    background: #555;
}
</style>
</head>

<body>

<h1>WLED Mast</h1>

<div class="grid">
    <button onclick="run('b1')">off</button>
    <button onclick="run('b2')">fireworks</button>
    <button onclick="run('b3')">sound<BR>reactive</button>
    <button onclick="run('b4')">bounch-balls</button>
    <button onclick="run('b5')">fire</button>
    <button onclick="run('b6')">juggle</button>
    <button onclick="run('b7')">swing</button>
    <button onclick="run('b8')">sparkle</button>
    <button onclick="run('b9')">popcorn</button>
    <button onclick="run('b10')">comet</button>
</div>

<script>
const API_KEY = "misuse-prevent";

function run(action) {
    fetch(`/action.php?action=${action}&key=${API_KEY}`)
        .then(r => r.json())
        .then(j => console.log(j))
        .catch(err => alert("Error"));
}
</script>

</body>
</html>

CODE for Wled API

<?php

$public_api_key = "misuse-prevent";
if (!isset($_GET['key']) || $_GET['key'] !== $public_api_key) {
    http_response_code(401);
    die("Unauthorized");
}

$action = $_GET['action'] ?? null;

// Map 10 buttons → WLED preset numbers
$allowed_actions = [
    "b1"  => 19,
    "b2"  => 22,
    "b3"  => 23,
    "b4"  => 20,
    "b5"  => 21,
    "b6"  => 3,
    "b7"  => 8,
    "b8"  => 2,
    "b9"  => 4,
    "b10" => 14
];

if (!$action || !isset($allowed_actions[$action])) {
    http_response_code(400);
    die("Invalid action");
}

$preset = $allowed_actions[$action];

// ---- WLED IP address ----
$wled_ip = "http://WLEDDEVICEIP";   // <-- CHANGE THIS

// API endpoint
$url = $wled_ip . "/win&PL=" . $preset;

// Call WLED directly
$ch = curl_init($url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 2);
curl_setopt($ch, CURLOPT_TIMEOUT, 2);

$response = curl_exec($ch);
$error = curl_error($ch);
curl_close($ch);

header("Content-Type: application/json");

if ($error) {
    echo json_encode(["ok" => false, "error" => $error]);
} else {
    echo json_encode(["ok" => true, "preset" => $preset]);
}
Computer, IOT / Domoticz

Working on the garden lights POC

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Working on my garden lights

DIY Garden Lights.

Working 12V relay bottom left, and upper right the Raspberry $ compute module board with NodeRed.

I made a little board to program the ATTiny85.

The RS485 chip I wanted to use (SN65HVD3082) came as SMD, luckily I have some SMD to THT/DIL boards. (breakoff)

Above on the breadboard : The SN65HVD3082EP on a little pcb, the ATTiny85 .
4×4 WS2812 led matrix will be my dimmable RGB garden light.

IOT / Domoticz

New MMWave boards.

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Several years ago, I used some radar boards to detect movement.

Radar module RCWL-0516 with MQTT

After that I used a MMWave board

Got some new sensors (HLK-LD2410B)

These are amazing, I’m using this in my Lab to switch on my big LED panel. You don’t need to move, it will detect human presence.
Another one I’m using in my living room.
It can power off all media at night (like TV, amplifier and lights)
It’s part of my home alarm system when we are away.

Now I got a new MMWave sensor (hlk-ld2450) , it can detect up to 3 persons and their location.


Screenshot from a Bluetooth phone app reading the sensor.