Godot + Arduino series: companion project code

Self-contained project code for the "Godot Isn't Just for Games" series:
Arduino sketches, the Python serial<->UDP bridge, and the Godot 4 projects,
one folder per article.

.gitignore

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+# Godot editor cache (regenerated locally)
+.godot/
+*.import
+export_presets.cfg
+
+# Python
+__pycache__/
+*.pyc
+.venv/
+venv/
+
+# OS / editor
+.DS_Store
+Thumbs.db
+*.swp

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Codebycandle
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

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+# Godot + Arduino — blog project code
+
+Companion code for the *"Godot Isn't Just for Games"* series on the
+[Codebycandle blog](https://codebycandle.com/blog) — using the Godot 4 game
+engine as a hardware control panel for an Arduino Uno.
+
+Each folder is a self-contained project for one article: the Arduino sketch, the
+Python serial↔UDP bridge, and the Godot project.
+
+| Part | Article | Folder | What it does |
+|------|---------|--------|--------------|
+| 1 | [Your First Arduino Round-Trip](https://codebycandle.com/blog/godot-arduino-led-first-light) | [`godot-arduino-1-led-first-light/`](./godot-arduino-1-led-first-light) | A Godot button lights a real LED on D13, over a Python-to-UDP bridge. |
+| 2 | A Live Joystick Dashboard *(coming soon)* | [`godot-arduino-2-joystick-dashboard/`](./godot-arduino-2-joystick-dashboard) | A KY-023 joystick streams `x,y,btn` telemetry into a glowing Godot XY pad. |
+
+## The shape of it
+
+```
+Arduino  <--USB serial-->  bridge.py  <--UDP 127.0.0.1-->  Godot
+```
+
+Godot has no serial support, so a ~40-line Python bridge owns the COM port and
+relays each line over UDP on localhost, in both directions. See each part's
+README for wiring and run steps.
+
+## Requirements
+
+- Arduino Uno (or compatible) + the Arduino IDE
+- Python 3 with `pyserial` (`pip install pyserial`)
+- [Godot 4](https://godotengine.org/) (standard build — no GDExtension needed)
+
+## License
+
+Released under the [MIT License](./LICENSE) — use it freely.

godot-arduino-1-led-first-light/README.md

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+# Part 1 — Your First Arduino Round-Trip
+
+Code for [*"Godot Isn't Just for Games: Your First Arduino Round-Trip"*](https://codebycandle.com/blog/godot-arduino-led-first-light).
+
+A button in a Godot 4 scene reaches down a USB cable — through a Python-to-UDP
+bridge — and lights a real LED on an Arduino Uno.
+
+## Contents
+
+```
+arduino/
+  LedBasics/LedBasics.ino   # reads L1/L0 off serial, drives the LED on D13
+  bridge/bridge.py          # serial <-> UDP relay (run this, leave it running)
+  bridge/ledtest.py         # quick standalone LED blink test (no Godot)
+godot/
+  ArduinoGodot/             # Godot 4 project: one styled toggle button
+```
+
+## Wiring
+
+D13 → 220 Ω resistor → LED long leg (anode); LED short leg (cathode) → GND.
+No breadboard? The Uno's onboard LED is already on D13.
+
+## Run it
+
+1. **Flash** `arduino/LedBasics/LedBasics.ino` to the Uno (Arduino IDE, 115200 baud).
+2. **Bridge:** `pip install pyserial`, then `python arduino/bridge/bridge.py`. Leave it running.
+3. **Godot:** open `godot/ArduinoGodot/` in Godot 4, press Play, click the button.
+
+The bridge auto-detects the board and reconnects if the cable pops out.

godot-arduino-1-led-first-light/arduino/LedBasics/LedBasics.ino

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+/*
+ * LedBasics.ino  —  Part 1: the minimal round trip.
+ *
+ * Godot sends "L1" / "L0" over USB serial (via the Python bridge) and this
+ * sketch toggles an LED. No sensors yet — Part 2 (JoystickBridge.ino) adds the
+ * joystick telemetry going the other way.
+ *
+ * PROTOCOL
+ *   IN (host -> Uno):  "L1" = LED on, "L0" = LED off  (newline-terminated)
+ *
+ * WIRING
+ *   D13 -> 220 ohm resistor -> LED anode (+, long leg)
+ *   LED cathode (-, short leg) -> GND
+ *   (D13 is also the Uno's onboard LED, so it flashes during every upload —
+ *    a free "is this pin alive" check before you've wired anything.)
+ */
+
+const uint8_t PIN_LED = 13;   // LED via 220 ohm resistor (also the onboard LED)
+
+char cmdBuf[8];
+uint8_t cmdLen = 0;
+
+void setup() {
+  Serial.begin(115200);
+  pinMode(PIN_LED, OUTPUT);
+  digitalWrite(PIN_LED, LOW);
+}
+
+void loop() {
+  // Commands in from Godot: "L1" / "L0", one per line.
+  while (Serial.available() > 0) {
+    char c = Serial.read();
+    if (c == '\n' || c == '\r') {
+      if (cmdLen >= 2 && cmdBuf[0] == 'L') {
+        digitalWrite(PIN_LED, cmdBuf[1] == '1' ? HIGH : LOW);
+      }
+      cmdLen = 0;
+    } else if (cmdLen < sizeof(cmdBuf) - 1) {
+      cmdBuf[cmdLen++] = c;
+    } else {
+      cmdLen = 0;  // overflow guard: drop the runt line
+    }
+  }
+}

godot-arduino-1-led-first-light/arduino/bridge/bridge.py

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+#!/usr/bin/env python3
+"""
+bridge.py  —  serial <-> UDP relay between the Arduino Uno and Godot (Main.gd)
+
+Godot never touches the serial port; it only speaks UDP:
+  * it LISTENS  on 127.0.0.1:4242  for telemetry  ("x,y,btn")
+  * it SENDS to 127.0.0.1:4243     for LED commands ("L1" / "L0")
+
+This bridge sits in the middle:
+  Arduino  --serial line "x,y,btn\\n"-->  bridge  --UDP-->  Godot :4242
+  Godot :4243  --UDP "L1"/"L0"-->        bridge  --serial-->  Arduino
+
+Double-click friendly: with no arguments it auto-detects the Arduino port and
+keeps the window open on exit so you can read any error. Override if needed:
+    python bridge.py --port COM3
+    python bridge.py --port COM3 --baud 115200   # baud must match the .ino
+
+Requires pyserial:  pip install pyserial
+"""
+
+import argparse
+import socket
+import sys
+import time
+
+try:
+    import serial  # pyserial
+    from serial.tools import list_ports
+except ImportError:
+    print("pyserial not installed. Run:  pip install pyserial")
+    input("\nPress Enter to close...")
+    sys.exit(1)
+
+TELEMETRY_ADDR = ("127.0.0.1", 4242)  # Godot listens here
+COMMAND_PORT = 4243                    # Godot sends LED commands here
+
+# Substrings that identify a typical Uno / clone in the port description.
+PORT_HINTS = ("arduino", "ch340", "usb-serial", "usb serial", "wchusb", "cp210")
+
+
+def pick_port() -> str:
+    """Return a serial port: the obvious Arduino one, else the only one, else ask."""
+    ports = list(list_ports.comports())
+    if not ports:
+        raise SystemExit("No serial ports found. Is the Uno plugged in?")
+
+    for p in ports:
+        blob = f"{p.description} {p.manufacturer or ''}".lower()
+        if any(h in blob for h in PORT_HINTS):
+            print(f"auto-detected {p.device}  ({p.description})")
+            return p.device
+
+    if len(ports) == 1:
+        print(f"using only port {ports[0].device}  ({ports[0].description})")
+        return ports[0].device
+
+    print("Multiple serial ports found:")
+    for i, p in enumerate(ports):
+        print(f"  [{i}] {p.device}  {p.description}")
+    choice = input("Pick a number: ").strip()
+    return ports[int(choice)].device
+
+
+def run(port: str, baud: int) -> None:
+    # UDP socket: sends telemetry to Godot AND receives LED commands from it.
+    # Bind to all interfaces ("") not just 127.0.0.1 — on some Windows setups a
+    # loopback-only bind won't see packets whose source the sender picked freely.
+    udp = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    udp.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    udp.bind(("", COMMAND_PORT))
+    udp.setblocking(False)
+
+    # Open the serial port. A short timeout keeps readline() from blocking forever.
+    ser = serial.Serial(port, baud, timeout=0.05)
+    time.sleep(2.0)  # Uno auto-resets when the port opens; wait for the sketch to boot
+    ser.reset_input_buffer()
+    print(f"bridge up: {port}@{baud}  ->  UDP {TELEMETRY_ADDR}, <- UDP :{COMMAND_PORT}")
+    print("leave this window open. Ctrl+C to quit.")
+
+    try:
+        while True:
+            # 1) Arduino -> Godot: forward each complete telemetry line.
+            line = ser.readline()  # b"x,y,btn\r\n" or b"" on timeout
+            if line:
+                text = line.strip()
+                if text:
+                    udp.sendto(text, TELEMETRY_ADDR)
+
+            # 2) Godot -> Arduino: drain any pending LED commands, newest applied last.
+            while True:
+                try:
+                    data, src = udp.recvfrom(64)
+                except BlockingIOError:
+                    break
+                except ConnectionResetError:
+                    # Windows: a prior sendto hit a closed port; ICMP resets recv. Ignore.
+                    break
+                cmd = data.strip()
+                if cmd in (b"L1", b"L0"):
+                    ser.write(cmd + b"\n")
+                    ser.flush()
+                    print(f"cmd {cmd.decode()} from {src} -> serial")
+                else:
+                    print(f"ignored UDP {data!r} from {src}")
+    except KeyboardInterrupt:
+        pass
+    finally:
+        ser.close()
+        udp.close()
+        print("\nbridge closed.")
+
+
+def main() -> None:
+    ap = argparse.ArgumentParser(description="Arduino <-> Godot serial/UDP bridge")
+    ap.add_argument("--port", help="serial port, e.g. COM3 (auto-detected if omitted)")
+    ap.add_argument("--baud", type=int, default=115200, help="must match JoystickBridge.ino")
+    args = ap.parse_args()
+
+    try:
+        port = args.port or pick_port()
+        run(port, args.baud)
+    except Exception as e:
+        # Keep the window open so double-click users can actually read the error.
+        print(f"\nERROR: {e}")
+    input("\nPress Enter to close...")
+
+
+if __name__ == "__main__":
+    main()

godot-arduino-1-led-first-light/arduino/bridge/ledtest.py

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+#!/usr/bin/env python3
+"""
+ledtest.py  —  isolate the bridge's receive path from Godot.
+
+Sends a single LED command straight to the bridge's command port, exactly like
+Godot does. If the running bridge prints "cmd L1 ... -> serial" (and the LED
+lights), the bridge's receive side is fine and any failure is on Godot's end.
+If the bridge stays silent even for this, the problem is the bridge/binding.
+
+Usage (with bridge.py already running):
+    python ledtest.py L1     # turn LED on
+    python ledtest.py L0     # turn LED off
+"""
+
+import socket
+import sys
+
+msg = (sys.argv[1] if len(sys.argv) > 1 else "L1").encode()
+sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+sock.sendto(msg, ("127.0.0.1", 4243))
+print(f"sent {msg!r} to 127.0.0.1:4243")

godot-arduino-1-led-first-light/godot/ArduinoGodot/LedBasics.gd

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+extends Control
+
+# Part 1 — the minimal round trip: a Godot button that toggles an LED on the
+# Arduino. Only the OUTBOUND (command) half of the link is used here; Part 2
+# adds inbound telemetry from the joystick.
+
+const COMMAND_ADDR := "127.0.0.1"
+const COMMAND_PORT := 4243
+
+@onready var led_button: Button = $Panel/LedButton
+
+var _udp_out := PacketPeerUDP.new()
+var _led_on := false
+
+func _ready() -> void:
+	# To SEND with PacketPeerUDP in Godot 4, use set_dest_address — NOT
+	# connect_to_host, which is for receiving and silently drops outbound packets.
+	_udp_out.set_dest_address(COMMAND_ADDR, COMMAND_PORT)
+	led_button.pressed.connect(_on_led_pressed)
+
+func _on_led_pressed() -> void:
+	_led_on = not _led_on
+	_udp_out.put_packet(("L1" if _led_on else "L0").to_utf8_buffer())
+	led_button.text = "LED: ON" if _led_on else "LED: OFF"

godot-arduino-1-led-first-light/godot/ArduinoGodot/LedBasics.gd.uid

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+uid://ctgyyk0it7dpd

godot-arduino-1-led-first-light/godot/ArduinoGodot/LedBasics.tscn

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+[gd_scene load_steps=6 format=3]
+
+[ext_resource type="Script" path="res://LedBasics.gd" id="1_led"]
+
+[sub_resource type="StyleBoxFlat" id="bg"]
+bg_color = Color(0.043, 0.055, 0.078, 1)
+
+[sub_resource type="StyleBoxFlat" id="btn_normal"]
+bg_color = Color(0.11, 0.145, 0.204, 1)
+border_width_left = 1
+border_width_top = 1
+border_width_right = 1
+border_width_bottom = 1
+border_color = Color(0.2, 0.6, 1, 0.5)
+corner_radius_top_left = 8
+corner_radius_top_right = 8
+corner_radius_bottom_right = 8
+corner_radius_bottom_left = 8
+
+[sub_resource type="StyleBoxFlat" id="btn_hover"]
+bg_color = Color(0.145, 0.196, 0.278, 1)
+border_width_left = 1
+border_width_top = 1
+border_width_right = 1
+border_width_bottom = 1
+border_color = Color(0.3, 0.7, 1, 1)
+corner_radius_top_left = 8
+corner_radius_top_right = 8
+corner_radius_bottom_right = 8
+corner_radius_bottom_left = 8
+
+[sub_resource type="StyleBoxFlat" id="btn_pressed"]
+bg_color = Color(0.2, 0.6, 1, 1)
+corner_radius_top_left = 8
+corner_radius_top_right = 8
+corner_radius_bottom_right = 8
+corner_radius_bottom_left = 8
+
+[node name="Main" type="Control"]
+layout_mode = 3
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+script = ExtResource("1_led")
+
+[node name="Panel" type="Panel" parent="."]
+layout_mode = 1
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+theme_override_styles/panel = SubResource("bg")
+
+[node name="Title" type="Label" parent="Panel"]
+layout_mode = 0
+offset_left = 40.0
+offset_top = 96.0
+offset_right = 480.0
+offset_bottom = 130.0
+theme_override_colors/font_color = Color(0.85, 0.93, 1, 1)
+theme_override_font_sizes/font_size = 24
+text = "GODOT + ARDUINO: LED"
+horizontal_alignment = 1
+vertical_alignment = 1
+
+[node name="Subtitle" type="Label" parent="Panel"]
+layout_mode = 0
+offset_left = 40.0
+offset_top = 132.0
+offset_right = 480.0
+offset_bottom = 152.0
+theme_override_colors/font_color = Color(0.4, 0.55, 0.7, 1)
+theme_override_font_sizes/font_size = 12
+text = "· click to reach down the wire ·"
+horizontal_alignment = 1
+vertical_alignment = 1
+
+[node name="LedButton" type="Button" parent="Panel"]
+layout_mode = 0
+offset_left = 150.0
+offset_top = 220.0
+offset_right = 370.0
+offset_bottom = 284.0
+theme_override_colors/font_color = Color(0.85, 0.93, 1, 1)
+theme_override_colors/font_hover_color = Color(1, 1, 1, 1)
+theme_override_colors/font_pressed_color = Color(0.043, 0.055, 0.078, 1)
+theme_override_font_sizes/font_size = 18
+theme_override_styles/normal = SubResource("btn_normal")
+theme_override_styles/hover = SubResource("btn_hover")
+theme_override_styles/pressed = SubResource("btn_pressed")
+theme_override_styles/focus = SubResource("btn_normal")
+text = "LED: OFF"

godot-arduino-1-led-first-light/godot/ArduinoGodot/project.godot

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+; Engine configuration file.
+; It's best edited using the editor UI and not directly,
+; since the parameters that go here are not all obvious.
+;
+; Format:
+;   [section] ; section goes between []
+;   param=value ; assign values to parameters
+
+config_version=5
+
+[application]
+
+config/name="ArduinoGodot"
+run/main_scene="res://LedBasics.tscn"
+config/features=PackedStringArray("4.7")
+
+[display]
+
+window/size/viewport_width=520
+window/size/viewport_height=610
+
+[dotnet]
+
+project/assembly_name="ArduinoGodot"

godot-arduino-2-joystick-dashboard/README.md

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+# Part 2 — A Live Joystick Dashboard
+
+Code for *"Godot Isn't Just for Games: A Live Joystick Dashboard"* **(article coming soon).**
+
+Builds on [Part 1](../godot-arduino-1-led-first-light): a 2-axis KY-023 joystick streams
+its position up the same bridge into a Godot console — a glowing dot tracks the
+stick across an XY pad in real time, with the LED button still working.
+
+## Contents
+
+```
+arduino/
+  JoystickBridge/JoystickBridge.ino   # streams "x,y,btn" + still drives the LED
+  bridge/bridge.py                    # same serial <-> UDP relay as Part 1
+godot/
+  ArduinoGodot/                       # Godot 4 project: XY pad + dot + LED button
+```
+
+## Wiring (adds to Part 1)
+
+KY-023 joystick: `+5V`→5V, `GND`→GND, `VRx`→A0, `VRy`→A1, `SW`→D2. Keep the
+LED from Part 1 on D13.
+
+## Run it
+
+1. **Flash** `arduino/JoystickBridge/JoystickBridge.ino` to the Uno.
+2. **Bridge:** `python arduino/bridge/bridge.py` (leave running).
+3. **Godot:** open `godot/ArduinoGodot/` in Godot 4 and press Play — move the stick.

godot-arduino-2-joystick-dashboard/arduino/JoystickBridge/JoystickBridge.ino

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+/*
+ * JoystickBridge.ino  —  Arduino Uno <-> Godot (ArduinoGodot/Main.gd)
+ *
+ * Talks plain serial lines to the UDP<->serial bridge process, which forwards
+ * telemetry to Godot on UDP 4242 and relays LED commands from UDP 4243.
+ *
+ * PROTOCOL (must match Main.gd)
+ *   OUT (Uno -> host):  "x,y,btn\n"   raw 10-bit ADC, e.g. "512,498,1"
+ *                       btn = 1 when the stick's push-button is pressed.
+ *   IN  (host -> Uno):  "L1" = LED on, "L0" = LED off  (newline optional)
+ *
+ * WIRING (KY-023 2-axis analog joystick + external LED)
+ *   Joystick  +5V / VCC  -> 5V
+ *   Joystick  GND        -> GND
+ *   Joystick  VRx        -> A0
+ *   Joystick  VRy        -> A1
+ *   Joystick  SW         -> D2   (uses internal pull-up; pressed = LOW)
+ *
+ *   LED:  D13 -> 220 ohm resistor -> LED anode (+, long leg)
+ *         LED cathode (-, short leg) -> GND
+ *   (D13 is also the Uno's onboard LED, so it flashes during every upload —
+ *    a free "is this pin alive" check. 220-330 ohm keeps it near ~15 mA.)
+ */
+
+const uint8_t PIN_VRX = A0;   // joystick X axis
+const uint8_t PIN_VRY = A1;   // joystick Y axis
+const uint8_t PIN_SW  = 2;    // joystick push-button (active LOW)
+const uint8_t PIN_LED = 13;   // external LED through a 220 ohm resistor (also onboard LED)
+
+const unsigned long BAUD      = 115200;  // must match the bridge process
+const unsigned long SEND_MS   = 16;      // ~60 Hz telemetry
+
+unsigned long lastSend = 0;
+char cmdBuf[8];
+uint8_t cmdLen = 0;
+
+void setup() {
+  Serial.begin(BAUD);
+  pinMode(PIN_SW, INPUT_PULLUP);
+  pinMode(PIN_LED, OUTPUT);
+  digitalWrite(PIN_LED, LOW);
+}
+
+void loop() {
+  handleCommands();
+
+  unsigned long now = millis();
+  if (now - lastSend >= SEND_MS) {
+    lastSend = now;
+    int x = analogRead(PIN_VRX);           // 0..1023
+    int y = analogRead(PIN_VRY);           // 0..1023
+    int btn = (digitalRead(PIN_SW) == LOW) // pull-up: LOW == pressed
+              ? 1 : 0;                     // Godot wants 1 = pressed
+
+    // "x,y,btn\n"
+    Serial.print(x);
+    Serial.print(',');
+    Serial.print(y);
+    Serial.print(',');
+    Serial.println(btn);
+  }
+}
+
+// Parse newline-terminated commands. Recognizes "L1" / "L0".
+void handleCommands() {
+  while (Serial.available() > 0) {
+    char c = Serial.read();
+    if (c == '\n' || c == '\r') {
+      if (cmdLen >= 2 && cmdBuf[0] == 'L') {
+        digitalWrite(PIN_LED, cmdBuf[1] == '1' ? HIGH : LOW);
+      }
+      cmdLen = 0;
+    } else if (cmdLen < sizeof(cmdBuf) - 1) {
+      cmdBuf[cmdLen++] = c;
+    } else {
+      cmdLen = 0;  // overflow guard: drop the runt line
+    }
+  }
+}

godot-arduino-2-joystick-dashboard/arduino/bridge/bridge.py

@@ -0,0 +1,129 @@
+#!/usr/bin/env python3
+"""
+bridge.py  —  serial <-> UDP relay between the Arduino Uno and Godot (Main.gd)
+
+Godot never touches the serial port; it only speaks UDP:
+  * it LISTENS  on 127.0.0.1:4242  for telemetry  ("x,y,btn")
+  * it SENDS to 127.0.0.1:4243     for LED commands ("L1" / "L0")
+
+This bridge sits in the middle:
+  Arduino  --serial line "x,y,btn\\n"-->  bridge  --UDP-->  Godot :4242
+  Godot :4243  --UDP "L1"/"L0"-->        bridge  --serial-->  Arduino
+
+Double-click friendly: with no arguments it auto-detects the Arduino port and
+keeps the window open on exit so you can read any error. Override if needed:
+    python bridge.py --port COM3
+    python bridge.py --port COM3 --baud 115200   # baud must match the .ino
+
+Requires pyserial:  pip install pyserial
+"""
+
+import argparse
+import socket
+import sys
+import time
+
+try:
+    import serial  # pyserial
+    from serial.tools import list_ports
+except ImportError:
+    print("pyserial not installed. Run:  pip install pyserial")
+    input("\nPress Enter to close...")
+    sys.exit(1)
+
+TELEMETRY_ADDR = ("127.0.0.1", 4242)  # Godot listens here
+COMMAND_PORT = 4243                    # Godot sends LED commands here
+
+# Substrings that identify a typical Uno / clone in the port description.
+PORT_HINTS = ("arduino", "ch340", "usb-serial", "usb serial", "wchusb", "cp210")
+
+
+def pick_port() -> str:
+    """Return a serial port: the obvious Arduino one, else the only one, else ask."""
+    ports = list(list_ports.comports())
+    if not ports:
+        raise SystemExit("No serial ports found. Is the Uno plugged in?")
+
+    for p in ports:
+        blob = f"{p.description} {p.manufacturer or ''}".lower()
+        if any(h in blob for h in PORT_HINTS):
+            print(f"auto-detected {p.device}  ({p.description})")
+            return p.device
+
+    if len(ports) == 1:
+        print(f"using only port {ports[0].device}  ({ports[0].description})")
+        return ports[0].device
+
+    print("Multiple serial ports found:")
+    for i, p in enumerate(ports):
+        print(f"  [{i}] {p.device}  {p.description}")
+    choice = input("Pick a number: ").strip()
+    return ports[int(choice)].device
+
+
+def run(port: str, baud: int) -> None:
+    # UDP socket: sends telemetry to Godot AND receives LED commands from it.
+    # Bind to all interfaces ("") not just 127.0.0.1 — on some Windows setups a
+    # loopback-only bind won't see packets whose source the sender picked freely.
+    udp = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    udp.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    udp.bind(("", COMMAND_PORT))
+    udp.setblocking(False)
+
+    # Open the serial port. A short timeout keeps readline() from blocking forever.
+    ser = serial.Serial(port, baud, timeout=0.05)
+    time.sleep(2.0)  # Uno auto-resets when the port opens; wait for the sketch to boot
+    ser.reset_input_buffer()
+    print(f"bridge up: {port}@{baud}  ->  UDP {TELEMETRY_ADDR}, <- UDP :{COMMAND_PORT}")
+    print("leave this window open. Ctrl+C to quit.")
+
+    try:
+        while True:
+            # 1) Arduino -> Godot: forward each complete telemetry line.
+            line = ser.readline()  # b"x,y,btn\r\n" or b"" on timeout
+            if line:
+                text = line.strip()
+                if text:
+                    udp.sendto(text, TELEMETRY_ADDR)
+
+            # 2) Godot -> Arduino: drain any pending LED commands, newest applied last.
+            while True:
+                try:
+                    data, src = udp.recvfrom(64)
+                except BlockingIOError:
+                    break
+                except ConnectionResetError:
+                    # Windows: a prior sendto hit a closed port; ICMP resets recv. Ignore.
+                    break
+                cmd = data.strip()
+                if cmd in (b"L1", b"L0"):
+                    ser.write(cmd + b"\n")
+                    ser.flush()
+                    print(f"cmd {cmd.decode()} from {src} -> serial")
+                else:
+                    print(f"ignored UDP {data!r} from {src}")
+    except KeyboardInterrupt:
+        pass
+    finally:
+        ser.close()
+        udp.close()
+        print("\nbridge closed.")
+
+
+def main() -> None:
+    ap = argparse.ArgumentParser(description="Arduino <-> Godot serial/UDP bridge")
+    ap.add_argument("--port", help="serial port, e.g. COM3 (auto-detected if omitted)")
+    ap.add_argument("--baud", type=int, default=115200, help="must match JoystickBridge.ino")
+    args = ap.parse_args()
+
+    try:
+        port = args.port or pick_port()
+        run(port, args.baud)
+    except Exception as e:
+        # Keep the window open so double-click users can actually read the error.
+        print(f"\nERROR: {e}")
+    input("\nPress Enter to close...")
+
+
+if __name__ == "__main__":
+    main()

godot-arduino-2-joystick-dashboard/godot/ArduinoGodot/LedBasics.gd

@@ -0,0 +1,24 @@
+extends Control
+
+# Part 1 — the minimal round trip: a Godot button that toggles an LED on the
+# Arduino. Only the OUTBOUND (command) half of the link is used here; Part 2
+# adds inbound telemetry from the joystick.
+
+const COMMAND_ADDR := "127.0.0.1"
+const COMMAND_PORT := 4243
+
+@onready var led_button: Button = $Panel/LedButton
+
+var _udp_out := PacketPeerUDP.new()
+var _led_on := false
+
+func _ready() -> void:
+	# To SEND with PacketPeerUDP in Godot 4, use set_dest_address — NOT
+	# connect_to_host, which is for receiving and silently drops outbound packets.
+	_udp_out.set_dest_address(COMMAND_ADDR, COMMAND_PORT)
+	led_button.pressed.connect(_on_led_pressed)
+
+func _on_led_pressed() -> void:
+	_led_on = not _led_on
+	_udp_out.put_packet(("L1" if _led_on else "L0").to_utf8_buffer())
+	led_button.text = "LED: ON" if _led_on else "LED: OFF"

godot-arduino-2-joystick-dashboard/godot/ArduinoGodot/LedBasics.gd.uid

@@ -0,0 +1 @@
+uid://ctgyyk0it7dpd

godot-arduino-2-joystick-dashboard/godot/ArduinoGodot/LedBasics.tscn

@@ -0,0 +1,91 @@
+[gd_scene load_steps=6 format=3]
+
+[ext_resource type="Script" path="res://LedBasics.gd" id="1_led"]
+
+[sub_resource type="StyleBoxFlat" id="bg"]
+bg_color = Color(0.043, 0.055, 0.078, 1)
+
+[sub_resource type="StyleBoxFlat" id="btn_normal"]
+bg_color = Color(0.11, 0.145, 0.204, 1)
+border_width_left = 1
+border_width_top = 1
+border_width_right = 1
+border_width_bottom = 1
+border_color = Color(0.2, 0.6, 1, 0.5)
+corner_radius_top_left = 8
+corner_radius_top_right = 8
+corner_radius_bottom_right = 8
+corner_radius_bottom_left = 8
+
+[sub_resource type="StyleBoxFlat" id="btn_hover"]
+bg_color = Color(0.145, 0.196, 0.278, 1)
+border_width_left = 1
+border_width_top = 1
+border_width_right = 1
+border_width_bottom = 1
+border_color = Color(0.3, 0.7, 1, 1)
+corner_radius_top_left = 8
+corner_radius_top_right = 8
+corner_radius_bottom_right = 8
+corner_radius_bottom_left = 8
+
+[sub_resource type="StyleBoxFlat" id="btn_pressed"]
+bg_color = Color(0.2, 0.6, 1, 1)
+corner_radius_top_left = 8
+corner_radius_top_right = 8
+corner_radius_bottom_right = 8
+corner_radius_bottom_left = 8
+
+[node name="Main" type="Control"]
+layout_mode = 3
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+script = ExtResource("1_led")
+
+[node name="Panel" type="Panel" parent="."]
+layout_mode = 1
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+theme_override_styles/panel = SubResource("bg")
+
+[node name="Title" type="Label" parent="Panel"]
+layout_mode = 0
+offset_left = 40.0
+offset_top = 96.0
+offset_right = 480.0
+offset_bottom = 130.0
+theme_override_colors/font_color = Color(0.85, 0.93, 1, 1)
+theme_override_font_sizes/font_size = 24
+text = "GODOT + ARDUINO: LED"
+horizontal_alignment = 1
+vertical_alignment = 1
+
+[node name="Subtitle" type="Label" parent="Panel"]
+layout_mode = 0
+offset_left = 40.0
+offset_top = 132.0
+offset_right = 480.0
+offset_bottom = 152.0
+theme_override_colors/font_color = Color(0.4, 0.55, 0.7, 1)
+theme_override_font_sizes/font_size = 12
+text = "· click to reach down the wire ·"
+horizontal_alignment = 1
+vertical_alignment = 1
+
+[node name="LedButton" type="Button" parent="Panel"]
+layout_mode = 0
+offset_left = 150.0
+offset_top = 220.0
+offset_right = 370.0
+offset_bottom = 284.0
+theme_override_colors/font_color = Color(0.85, 0.93, 1, 1)
+theme_override_colors/font_hover_color = Color(1, 1, 1, 1)
+theme_override_colors/font_pressed_color = Color(0.043, 0.055, 0.078, 1)
+theme_override_font_sizes/font_size = 18
+theme_override_styles/normal = SubResource("btn_normal")
+theme_override_styles/hover = SubResource("btn_hover")
+theme_override_styles/pressed = SubResource("btn_pressed")
+theme_override_styles/focus = SubResource("btn_normal")
+text = "LED: OFF"

godot-arduino-2-joystick-dashboard/godot/ArduinoGodot/Main.gd

@@ -0,0 +1,63 @@
+extends Control
+
+const TELEMETRY_PORT := 4242
+const COMMAND_ADDR := "127.0.0.1"
+const COMMAND_PORT := 4243
+
+const ADC_MAX := 1023.0
+const SMOOTH_SPEED := 12.0   # higher = snappier, lower = floatier
+
+@onready var led_button: Button = $Panel/LedButton
+@onready var pad: Panel = $Panel/Pad
+@onready var dot: ColorRect = $Panel/Pad/Dot
+
+var _udp_in := PacketPeerUDP.new()
+var _udp_out := PacketPeerUDP.new()
+
+var _target_x := 512.0   # rest near center so the dot starts in the middle
+var _target_y := 512.0
+var _smoothed_x := 512.0
+var _smoothed_y := 512.0
+var _btn_pressed := false
+var _led_on := false
+
+const COLOR_DOT_IDLE := Color(0.3, 0.7, 1.0)     # cyan
+const COLOR_DOT_PRESSED := Color(0.2, 1.0, 0.4)  # green
+
+func _ready() -> void:
+	_udp_in.bind(TELEMETRY_PORT, "127.0.0.1")
+	# set_dest_address is the reliable way to *send* with PacketPeerUDP in Godot 4;
+	# connect_to_host is aimed at receiving and can silently drop outbound packets.
+	_udp_out.set_dest_address(COMMAND_ADDR, COMMAND_PORT)
+	led_button.pressed.connect(_on_led_pressed)
+
+func _process(delta: float) -> void:
+	# Drain the queue; the newest packet wins. Format: "x,y,btn" e.g. "512,498,0"
+	while _udp_in.get_available_packet_count() > 0:
+		var parts := _udp_in.get_packet().get_string_from_utf8().split(",")
+		if parts.size() >= 3 and parts[0].is_valid_int() and parts[1].is_valid_int():
+			_target_x = float(parts[0])
+			_target_y = float(parts[1])
+			_btn_pressed = parts[2].strip_edges() == "1"
+
+	# Frame-rate-independent smoothing so the dot glides instead of twitching.
+	var t := 1.0 - exp(-SMOOTH_SPEED * delta)
+	_smoothed_x = lerpf(_smoothed_x, _target_x, t)
+	_smoothed_y = lerpf(_smoothed_y, _target_y, t)
+
+	# Normalize raw ADC (0..1023) to 0..1.
+	var nx := clampf(_smoothed_x / ADC_MAX, 0.0, 1.0)
+	var ny := clampf(_smoothed_y / ADC_MAX, 0.0, 1.0)
+
+	# Move the dot within the pad. Invert Y so pushing the stick UP moves the dot UP.
+	# (If it feels backwards, change "1.0 - ny" to "ny", or swap for X below.)
+	var travel := pad.size - dot.size
+	dot.position = Vector2(nx * travel.x, (1.0 - ny) * travel.y)
+
+	# Reflect the stick's push-button by recoloring the dot.
+	dot.color = COLOR_DOT_PRESSED if _btn_pressed else COLOR_DOT_IDLE
+
+func _on_led_pressed() -> void:
+	_led_on = not _led_on
+	_udp_out.put_packet(("L1" if _led_on else "L0").to_utf8_buffer())
+	led_button.text = "LED: ON" if _led_on else "LED: OFF"

godot-arduino-2-joystick-dashboard/godot/ArduinoGodot/Main.gd.uid

@@ -0,0 +1 @@
+uid://d103i6ghi3ydl

godot-arduino-2-joystick-dashboard/godot/ArduinoGodot/Main.tscn

@@ -0,0 +1,137 @@
+[gd_scene format=3 uid="uid://b81ornfxnvxxo"]
+
+[ext_resource type="Script" uid="uid://d103i6ghi3ydl" path="res://Main.gd" id="1_main"]
+
+[sub_resource type="StyleBoxFlat" id="bg"]
+bg_color = Color(0.043, 0.055, 0.078, 1)
+
+[sub_resource type="StyleBoxFlat" id="pad"]
+bg_color = Color(0.071, 0.09, 0.125, 1)
+border_width_left = 1
+border_width_top = 1
+border_width_right = 1
+border_width_bottom = 1
+border_color = Color(0.2, 0.6, 1, 0.55)
+corner_radius_top_left = 10
+corner_radius_top_right = 10
+corner_radius_bottom_right = 10
+corner_radius_bottom_left = 10
+shadow_color = Color(0.2, 0.6, 1, 0.15)
+shadow_size = 12
+
+[sub_resource type="StyleBoxFlat" id="btn_normal"]
+bg_color = Color(0.11, 0.145, 0.204, 1)
+border_width_left = 1
+border_width_top = 1
+border_width_right = 1
+border_width_bottom = 1
+border_color = Color(0.2, 0.6, 1, 0.5)
+corner_radius_top_left = 8
+corner_radius_top_right = 8
+corner_radius_bottom_right = 8
+corner_radius_bottom_left = 8
+
+[sub_resource type="StyleBoxFlat" id="btn_pressed"]
+bg_color = Color(0.2, 0.6, 1, 1)
+corner_radius_top_left = 8
+corner_radius_top_right = 8
+corner_radius_bottom_right = 8
+corner_radius_bottom_left = 8
+
+[sub_resource type="StyleBoxFlat" id="btn_hover"]
+bg_color = Color(0.145, 0.196, 0.278, 1)
+border_width_left = 1
+border_width_top = 1
+border_width_right = 1
+border_width_bottom = 1
+border_color = Color(0.3, 0.7, 1, 1)
+corner_radius_top_left = 8
+corner_radius_top_right = 8
+corner_radius_bottom_right = 8
+corner_radius_bottom_left = 8
+
+[node name="Main" type="Control" unique_id=2088197079]
+layout_mode = 3
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+grow_horizontal = 2
+grow_vertical = 2
+script = ExtResource("1_main")
+
+[node name="Panel" type="Panel" parent="." unique_id=2059422118]
+layout_mode = 1
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+grow_horizontal = 2
+grow_vertical = 2
+theme_override_styles/panel = SubResource("bg")
+
+[node name="Title" type="Label" parent="Panel" unique_id=1798584764]
+layout_mode = 0
+offset_left = 40.0
+offset_top = 28.0
+offset_right = 480.0
+offset_bottom = 58.0
+theme_override_colors/font_color = Color(0.85, 0.93, 1, 1)
+theme_override_font_sizes/font_size = 22
+text = "GODOT + ARDUINO DEMO"
+horizontal_alignment = 1
+vertical_alignment = 1
+
+[node name="Subtitle" type="Label" parent="Panel" unique_id=462472763]
+layout_mode = 0
+offset_left = 40.0
+offset_top = 60.0
+offset_right = 480.0
+offset_bottom = 78.0
+theme_override_colors/font_color = Color(0.4, 0.55, 0.7, 1)
+theme_override_font_sizes/font_size = 12
+text = "· real-time serial link ·"
+horizontal_alignment = 1
+vertical_alignment = 1
+
+[node name="Pad" type="Panel" parent="Panel" unique_id=1034082861]
+layout_mode = 0
+offset_left = 70.0
+offset_top = 104.0
+offset_right = 450.0
+offset_bottom = 484.0
+theme_override_styles/panel = SubResource("pad")
+
+[node name="CrosshairV" type="ColorRect" parent="Panel/Pad" unique_id=1237114789]
+layout_mode = 0
+offset_left = 189.0
+offset_right = 191.0
+offset_bottom = 380.0
+color = Color(0.2, 0.6, 1, 0.12)
+
+[node name="CrosshairH" type="ColorRect" parent="Panel/Pad" unique_id=1265685762]
+layout_mode = 0
+offset_top = 189.0
+offset_right = 380.0
+offset_bottom = 191.0
+color = Color(0.2, 0.6, 1, 0.12)
+
+[node name="Dot" type="ColorRect" parent="Panel/Pad" unique_id=2003621157]
+layout_mode = 0
+offset_right = 28.0
+offset_bottom = 28.0
+color = Color(0.3, 0.7, 1, 1)
+
+[node name="LedButton" type="Button" parent="Panel" unique_id=1325564653]
+layout_mode = 0
+offset_left = 160.0
+offset_top = 516.0
+offset_right = 360.0
+offset_bottom = 566.0
+theme_override_colors/font_color = Color(0.85, 0.93, 1, 1)
+theme_override_colors/font_pressed_color = Color(0.043, 0.055, 0.078, 1)
+theme_override_colors/font_hover_color = Color(1, 1, 1, 1)
+theme_override_font_sizes/font_size = 18
+theme_override_styles/normal = SubResource("btn_normal")
+theme_override_styles/pressed = SubResource("btn_pressed")
+theme_override_styles/hover = SubResource("btn_hover")
+theme_override_styles/focus = SubResource("btn_normal")
+text = "LED: OFF"

godot-arduino-2-joystick-dashboard/godot/ArduinoGodot/project.godot

@@ -0,0 +1,24 @@
+; Engine configuration file.
+; It's best edited using the editor UI and not directly,
+; since the parameters that go here are not all obvious.
+;
+; Format:
+;   [section] ; section goes between []
+;   param=value ; assign values to parameters
+
+config_version=5
+
+[application]
+
+config/name="ArduinoGodot"
+run/main_scene="res://Main.tscn"
+config/features=PackedStringArray("4.7")
+
+[display]
+
+window/size/viewport_width=520
+window/size/viewport_height=610
+
+[dotnet]
+
+project/assembly_name="ArduinoGodot"