alpon_x4_control_led.py

import smbus2 as smbus 
import time

# Initialize the I2C bus
bus = smbus.SMBus(1)
dev_addr = 0x20  # Address of the TCA6408A
conf_addr = 0x03  # Address to configure the pins
write_addr = 0x01  # Address to write data to the pins

# Function to set the LED color
def set_led_color(red, green, blue):
    """
    Set the color of the RGB LED.
    :param red: Red component (0: on, 1: off)
    :param green: Green component (0: on, 1: off)
    :param blue: Blue component (0: on, 1: off)
    """
    # read the current state
    led_state = bus.read_byte_data(dev_addr, 0x0)

    # set each bit appropriately
    # P2 -> Red (bit 2)
    # P3 -> Green (bit 3)
    # P4 -> Blue (bit 4)
    for p,v in zip([2,3,4],[red,green,blue]):
        led_state = led_state | (1<<p) if v == 1 else led_state & ~(1<<p)

    # Write the state to the TCA6408A
    bus.write_byte_data(dev_addr, write_addr, led_state)

# Configure the pins as outputs
conf_data = 0x00  # All pins are set as outputs
bus.write_byte_data(dev_addr, conf_addr, conf_data)

try:
    while True:
        # Turn the LED red
        set_led_color(0, 1, 1)
        print("LED: Red")
        time.sleep(1)

        # Turn the LED green
        set_led_color(1, 0, 1)
        print("LED: Green")
        time.sleep(1)

        # Turn the LED blue
        set_led_color(1, 1, 0)
        print("LED: Blue")
        time.sleep(1)

        # Turn the LED off
        set_led_color(1, 1, 1)
        print("LED: Off")
        time.sleep(1)

except KeyboardInterrupt:
    # Turn the LED off when the program is stopped
    set_led_color(1, 1, 1)
    print("Program stopped.")