added hardware

arduino/README.md

@@ -0,0 +1,50 @@
+# Nexus Game Controller
+
+A game controller using a Seeed Studio XIAO nRF52840 Sense board that emulates a Bluetooth keyboard.
+
+## Hardware
+- [Seeed Studio XIAO nRF52840 Sense](#https://www.seeedstudio.com/Seeed-XIAO-BLE-Sense-nRF52840-p-5253.html)
+- 9 [push buttons](https://rpishop.cz/komponenty/6128-pimoroni-cerne-arkadove-tlacitko.html) connected to pins D1-D6 and D8-D10.
+
+## Features
+- **Bluetooth LE Keyboard:** Connects to any computer or mobile device as a standard keyboard.
+- **Multi-Event Buttons:** Each of the 9 buttons supports three types of interactions:
+    - Single Click
+    - Double Click
+    - Long Press
+- **Character Mapping:** Each button event sends a unique character.
+- **Serial Debugging:** Outputs button events and Bluetooth connection status to the serial monitor.
+
+## Button Mappings
+
+| Button | Single Click | Double Click | Long Press |
+|--------|--------------|--------------|------------|
+| D1     | `a`          | `b`          | `c`        |
+| D2     | `d`          | `e`          | `f`        |
+| D3     | `g`          | `h`          | `i`        |
+| D4     | `j`          | `k`          | `l`        |
+| D5     | `m`          | `n`          | `o`        |
+| D6     | `p`          | `q`          | `r`        |
+| D8     | `s`          | `t`          | `u`        |
+| D9     | `v`          | `w`          | `x`        |
+| D10    | `y`          | `z`          | `1`        |
+
+## How to Use
+
+1.  **Setup Arduino IDE:**
+    - Install the "Seeed nRF52 Boards" package.
+    - Select "Seeed XIAO BLE Sense - nRF52840" as the board.
+    - Install the "Adafruit Bluefruit nRF52" library.
+2.  **Upload:** Compile and upload the [sketch](/arduino/sketch.ino) to your XIAO board.
+3.  **Connect:** Scan for Bluetooth devices on your computer or mobile device and connect to "Nexus Game Controller".
+4.  **Play:** Press the buttons to send keystrokes. Open the Serial Monitor at 115200 baud to see debug information.
+
+## 3D Print
+
+![Hexagon](/arduino/Krabicka_hexagon.png)
+
+You can import the [3mf file](/arduino/Krabicka_hexagon.3mf) to your slicer for printing.
+
+## Customize your design
+
+Open the [3D model](/arduino/Krabicka_hexagon.FCStd) in FreeCAD to model your changes.

arduino/sketch.ino

@@ -0,0 +1,178 @@
+#include <bluefruit.h>
+#include <bluefruit.h>
+
+// Pin definitions for the 9 buttons
+const int buttonPins[] = {1, 2, 3, 4, 5, 6, 8, 9, 10};
+const int numButtons = sizeof(buttonPins) / sizeof(buttonPins[0]);
+
+// Button state tracking
+struct Button {
+  int pin;
+  bool lastState;
+  unsigned long lastDebounceTime;
+  unsigned long pressTime;
+  int clickCount;
+  bool isPressed;
+  bool longPressHandled;
+};
+
+Button buttons[numButtons];
+
+// Debounce and timing constants
+const unsigned long debounceDelay = 50;
+const unsigned long doubleClickDelay = 400;
+const unsigned long longPressDelay = 1000;
+
+// BLE Keyboard object
+BLEDis bledis;
+BLEHidAdafruit blehid;
+
+// Character mapping for each event
+// 9 buttons * 3 events/button = 27 characters
+const char eventChars[numButtons][3] = {
+  {'a', 'b', 'c'}, // Button D1: single, double, long
+  {'d', 'e', 'f'}, // Button D2: single, double, long
+  {'g', 'h', 'i'}, // Button D3: single, double, long
+  {'j', 'k', 'l'}, // Button D4: single, double, long
+  {'m', 'n', 'o'}, // Button D5: single, double, long
+  {'p', 'q', 'r'}, // Button D6: single, double, long
+  {'s', 't', 'u'}, // Button D8: single, double, long
+  {'v', 'w', 'x'}, // Button D9: single, double, long
+  {'y', 'z', '1'}  // Button D10: single, double, long
+};
+
+void setup() {
+  Serial.begin(115200);
+  //while ( !Serial ) delay(10); // Wait for serial port to connect.
+
+  Serial.println("Nexus Game Controller Starting...");
+
+  // Initialize buttons
+  for (int i = 0; i < numButtons; i++) {
+    buttons[i].pin = buttonPins[i];
+    pinMode(buttons[i].pin, INPUT_PULLUP);
+    buttons[i].lastState = HIGH;
+    buttons[i].lastDebounceTime = 0;
+    buttons[i].pressTime = 0;
+    buttons[i].clickCount = 0;
+    buttons[i].isPressed = false;
+    buttons[i].longPressHandled = false;
+  }
+
+  // Setup Bluetooth
+  Bluefruit.begin();
+  Bluefruit.setName("Nexus Game Controller");
+  Bluefruit.setTxPower(4);
+
+  // Configure and start BLE services
+  bledis.setManufacturer("Seeed Studio");
+  bledis.setModel("XIAO nRF52840 Sense");
+  bledis.begin();
+
+  blehid.begin();
+
+  // Start advertising
+  Bluefruit.Advertising.addFlags(BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE);
+  Bluefruit.Advertising.addTxPower();
+  Bluefruit.Advertising.addAppearance(BLE_APPEARANCE_HID_KEYBOARD);
+  Bluefruit.Advertising.addService(blehid);
+  Bluefruit.Advertising.addName();
+  
+  Bluefruit.Advertising.restartOnDisconnect(true);
+  Bluefruit.Advertising.setInterval(32, 244); // in unit of 0.625 ms
+  Bluefruit.Advertising.setFastTimeout(30); // number of seconds in fast advertising mode
+  Bluefruit.Advertising.start(0); // 0 = Don't stop advertising after n seconds
+
+  Serial.println("Advertising...");
+
+  // Set up connection/disconnection callbacks
+  Bluefruit.Periph.setConnectCallback(connect_callback);
+  Bluefruit.Periph.setDisconnectCallback(disconnect_callback);
+}
+
+void connect_callback(uint16_t conn_handle) {
+  (void) conn_handle;
+  Serial.println("Bluetooth connected");
+}
+
+void disconnect_callback(uint16_t conn_handle, uint8_t reason) {
+  (void) conn_handle;
+  (void) reason;
+  Serial.println("Bluetooth disconnected");
+}
+
+
+void loop() {
+  for (int i = 0; i < numButtons; i++) {
+    handleButton(&buttons[i], i);
+  }
+}
+
+void handleButton(Button* b, int buttonIndex) {
+  bool reading = digitalRead(b->pin);
+
+  // Debounce logic
+  if (reading != b->lastState) {
+    b->lastDebounceTime = millis();
+  }
+
+  if ((millis() - b->lastDebounceTime) > debounceDelay) {
+    // If the button state has been stable
+    if (reading == LOW && !b->isPressed) { // Button just pressed
+      b->isPressed = true;
+      b->pressTime = millis();
+      b->clickCount++;
+      b->longPressHandled = false;
+    } else if (reading == HIGH && b->isPressed) { // Button just released
+      b->isPressed = false;
+      if (!b->longPressHandled) {
+        // It's a click, but we need to wait for a potential double click
+      } else {
+        // This was a long press, so we do nothing on release
+        b->longPressHandled = false; // Reset for next time
+      }
+    }
+  }
+
+  // Check for long press
+  if (b->isPressed && !b->longPressHandled && (millis() - b->pressTime > longPressDelay)) {
+    triggerEvent(buttonIndex, 2); // Long Press
+    b->longPressHandled = true;
+    b->clickCount = 0; // Reset click count after a long press
+  }
+
+  // Check for single/double click timeout
+  if (b->clickCount > 0 && !b->isPressed && (millis() - b->pressTime > doubleClickDelay)) {
+    if (!b->longPressHandled) {
+      if (b->clickCount == 1) {
+        triggerEvent(buttonIndex, 0); // Single Click
+      } else if (b->clickCount == 2) {
+        triggerEvent(buttonIndex, 1); // Double Click
+      }
+    }
+    b->clickCount = 0;
+  }
+
+  b->lastState = reading;
+}
+
+void triggerEvent(int buttonIndex, int eventType) {
+  // eventType: 0 = single, 1 = double, 2 = long
+  char key = eventChars[buttonIndex][eventType];
+  
+  const char* eventStr[] = {"single click", "double click", "long press"};
+
+  Serial.print("Button D");
+  Serial.print(buttonPins[buttonIndex]);
+  Serial.print(" triggered ");
+  Serial.print(eventStr[eventType]);
+  Serial.print(" event. Character '");
+  Serial.print(key);
+  Serial.println("' has been sent.");
+
+  if (Bluefruit.connected()) {
+    blehid.keyPress(key);
+    delay(10); // a small delay to prevent flooding
+    blehid.keyRelease();
+  }
+}

docs/remote-control.md

@@ -4,8 +4,8 @@
 1. [HID Smart Buttons](#hid-smart-buttons)
 2. [MQTT Remote Control](#mqtt-remote-control)
     - [Mosquitto Installation Guide](#mosquitto-installation-guide)
-        - [Mosquitto MQTT Broker on Android 16's Native Linux VM](#mosquitto-mqtt-broker-on-android-16s-native-linux-vm)
+        - [Mosquitto MQTT Broker using `Termux` app](#mosquitto-mqtt-broker-using-termux-app)
-        - [Mosquitto MQTT Broker on older versions of Android then 16](#mosquitto-mqtt-broker-on-older-versions-of-android-then-16)
+        - [Mosquitto MQTT Broker with VPN on Android 16's Native Linux VM](#mosquitto-mqtt-broker-with-vpn-on-android-16s-native-linux-vm)
     - [Android Shortcut Setup](#android-shortcut-setup)
     - [Configure `Quick Tap` gesture to trigger the shortcut](#configure-quick-tap-gesture-to-trigger-the-shortcut)
     - [Testing with `mosquitto_pub` (via Termux)](#testing-with-mosquitto_pub-via-termux)
@@ -15,7 +15,7 @@
 ## HID Smart Buttons
 For an enhanced tactile experience, Nexus Timer supports Smart Buttons based on Bluetooth-connected microcontroller (e.g., XIAO nRF52840) implementing HID (Human Interface Device) protocol emulating a keyboard.
 
-*   **Buttons:** Connect 3 physical buttons, potentially extended (e.g., via 1.5m wires) for easy player access.
+*   **Buttons:** Connect 3 physical buttons, potentially extended e.g., via 1.5m wires for easy player access.
 *   **Configuration:**
     *   **Player 1's Button:** Single Click: Emulates a key press (e.g., 'a'). Configure this as Player 1's "Pass Turn / My Pause" hotkey in the app.
     *   **Player 2's Button:** Single Click: Emulates a key press (e.g., 'b'). Configure as Player 2's "Pass Turn / My Pause" hotkey.
@@ -24,14 +24,49 @@ For an enhanced tactile experience, Nexus Timer supports Smart Buttons based on
         *   **Player 3's Button:** Long Press: Emulates a key press (e.g., 's'). Configure as the "Global Stop/Pause All" hotkey in the app.
         *   **Player 3's Button:** Double Click: Emulates a key press (e.g., 'x'). Configure as the "Global Run All Timers" hotkey in the app.
     
+The code for the XIAO nRF52840 module with a 3D printing files can be found in the [arduino](/arduino) subdirectory.
+
 ## MQTT Remote Control
-Players can use their smartphones to send commands to Nexus Timer via MQTT. This requires an MQTT broker (like Mosquitto) on the same network.
+Alternatively to a dedicated smart buttons, players can use their smartphones to send commands to Nexus Timer via MQTT. This requires an MQTT broker (like Mosquitto) on the same network.
 
 ### Mosquitto Installation Guide
 
-#### Mosquitto MQTT Broker on Android 16's Native Linux VM
+#### Mosquitto MQTT Broker using `Termux` app
 
-This guide details how to install and configure the Mosquitto MQTT broker within the native `Linux Virtual Machine environment` introduced in Android 16. For older versions proceed to [Mosquitto MQTT Broker on older versions of Android then 16](#mosquitto-mqtt-broker-on-older-versions-of-android-then-16).
+1. **Install Termux** from the [Play Store](https://play.google.com/store/apps/details?id=com.termux) and run.
+2. **Update packages and install Mosquitto in Termux:**
+    ```bash
+    pkg update && pkg upgrade
+    pkg install mosquitto
+    ```
+3. **Configure the MQTT Broker:**
+    ```bash
+    nano $PREFIX/etc/mosquitto/mosquitto.conf
+    ```
+    Add the following configuration, then save and exit:
+    ```ini
+    # MQTT listener on port 1883
+    # MQTT connection from the HTTP Shortcut app
+    listener 1883 0.0.0.0
+    protocol mqtt
+
+    # WebSocket listener on port 9001
+    # MQTT over WebSocket connection from the PWA (Web App)
+    listener 9001 0.0.0.0
+    protocol websockets
+
+    # Allow clients to connect without username/password
+    allow_anonymous true
+    ```
+4. **Run Mosquitto with the configuration:**
+    ```bash
+    mosquitto -c $PREFIX/etc/mosquitto/mosquitto.conf
+    ```
+---
+
+#### Mosquitto MQTT Broker with VPN on Android 16's Native Linux VM
+
+This guide details how to install and configure the Mosquitto MQTT broker within the native `Linux Virtual Machine environment` introduced in Android 16. Note that ports exposed by the Mosquitto cannot be reached from LAN. The workarround is using a VPN (wireguard).
 
 1. **Enable the Linux Development Environment**
 
@@ -113,39 +148,6 @@ Your Mosquitto MQTT broker is now successfully configured and running on your An
 
 ---
 
-#### Mosquitto MQTT Broker on older versions of Android then 16
-
-1. **Install Termux** from the [Play Store](https://play.google.com/store/apps/details?id=com.termux) and run.
-2. **Update packages and install Mosquitto in Termux:**
-    ```bash
-    pkg update && pkg upgrade
-    pkg install mosquitto
-    ```
-3. **Configure the MQTT Broker:**
-    ```bash
-    nano $PREFIX/etc/mosquitto/mosquitto.conf
-    ```
-    Add the following configuration, then save and exit:
-    ```ini
-    # MQTT listener on port 1883
-    # MQTT connection from the HTTP Shortcut app
-    listener 1883 0.0.0.0
-    protocol mqtt
-
-    # WebSocket listener on port 9001
-    # MQTT over WebSocket connection from the PWA (Web App)
-    listener 9001 0.0.0.0
-    protocol websockets
-
-    # Allow clients to connect without username/password
-    allow_anonymous true
-    ```
-4. **Run Mosquitto with the configuration:**
-    ```bash
-    mosquitto -c $PREFIX/etc/mosquitto/mosquitto.conf
-    ```
----
-
 ### Android Shortcut Setup
 *   Install the `HTTP Shortcuts` app from the [Play Store](https://play.google.com/store/apps/details?id=ch.rmy.android.http_shortcuts).
 *   Create a new shortcut.