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.

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

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

godot-arduino-1-led-first-light/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-1-led-first-light/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://LedBasics.tscn"
+config/features=PackedStringArray("4.7")
+
+[display]
+
+window/size/viewport_width=520
+window/size/viewport_height=610
+
+[dotnet]
+
+project/assembly_name="ArduinoGodot"