import os
import serial
import struct
import time

conn = serial.Serial("COM3" if os.name == "nt" else "/dev/ttyACM0")

def change(channel, intensity):
    return struct.pack("B", (channel << 2) + intensity)

try:
    print("Blinking (1sec intervals)... [Press ^C to exit]\x1b[?25l")
    while True:
        print("\r\x1b[32m- vibrating -\x1b[0m", end="", flush=True)
        conn.write(change(0, 1))
        time.sleep(1)
        print("\r\x1b[35m- sleeping - \x1b[0m", end="", flush=True)
        conn.write(change(0, 0))
        time.sleep(1)
except KeyboardInterrupt:
    conn.write(change(0, 0))
    print("\x1b[?25h")