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.
This commit is contained in:
tyler parker
@@ -0,0 +1,79 @@
|
||||
/*
|
||||
* 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
|
||||
}
|
||||
}
|
||||
}
|
||||
@@ -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()
|
||||
Reference in New Issue
Block a user