import serial
import time
import struct

# Initialize serial connection
ser = serial.Serial('/dev/rfcomm0', 115200, timeout=0)

# 1. Accept frequency from the user
try:
    freq = int(input("Enter frequency to play: "))
except ValueError:
    print("Please enter a valid integer for frequency.")
    ser.close()
    exit()

# 2. Prepare the command
# -0x13 is the command byte (equivalent to -19 decimal)
# 'h' represents a 2-byte signed short (or 'H' for unsigned)
# ">b h" means: Big-Endian, 1-byte signed char, 2-byte integer
command_byte = -0x13
message = struct.pack("<bh", command_byte, freq)

# 3. Send and read
ser.write(message)

ser.close()