Python code for PCA9685 Servo Controller and Joystick Control

logitech_attack3_rpi.py

#!/usr/bin/env python

import time
import Adafruit_PCA9685
import evdev

# Initialise the PCA9685 using the default address (0x40).
pwm = Adafruit_PCA9685.PCA9685()

# Set frequency to 60hz, good for servos.
pwm.set_pwm_freq(60)

# Find the gamepad
devices = [evdev.InputDevice(path) for path in evdev.list_devices()]
for device in devices:
    if device.name == 'Logitech Logitech Attack 3':
        gamepad = evdev.InputDevice(device.path)

# Servo channel numbers
SERVO_X_CHANNEL = 0
SERVO_Y_CHANNEL = 1

# Servo minimum and maximum pulse lengths
SERVO_MIN_PULSE_LEN = 150  # Min pulse length out of 4096
SERVO_MAX_PULSE_LEN = 600  # Max pulse length out of 4096

# X and Y axis current positions
x_pos = 0
y_pos = 0

# Loop through events from the gamepad
for event in gamepad.read_loop():
    # Break out of the loop if program has been terminated
    if event.type == evdev.ecodes.EV_KEY and event.code == 316 and event.value == 0:
        break
    
    # Read joystick event and update position if it's X or Y axis
    if event.type == evdev.ecodes.EV_ABS:
        if event.code == 0:
            x_pos = event.value
        elif event.code == 1:
            y_pos = event.value

        # Convert joystick position to servo pulse length
        x_pulse_len = int((SERVO_MAX_PULSE_LEN - SERVO_MIN_PULSE_LEN) * (x_pos / 255.0) + SERVO_MIN_PULSE_LEN)
        y_pulse_len = int((SERVO_MAX_PULSE_LEN - SERVO_MIN_PULSE_LEN) * (y_pos / 255.0) + SERVO_MIN_PULSE_LEN)

        # Set the servo position
        pwm.set_pwm(SERVO_X_CHANNEL, 0, x_pulse_len)
        pwm.set_pwm(SERVO_Y_CHANNEL, 0, y_pulse_len)

        # Print current X and Y values
        print(f"X: {x_pos}, Y: {y_pos}")