vmr-6512.py

#!/usr/bin/env python3

"""
This script sets the frequency and pre-emphasis values for a device using a serial interface.

It takes a frequency argument in MHz and an optional pre-emphasis argument (default: 1).
The script sends commands to the device via the specified serial port to set the frequency
and pre-emphasis values.

Command line arguments:
    frequency (float): Frequency in MHz.
    --emphasis (int): Pre-emphasis value (default: 1).
"""

import argparse
import serial

# Define the command codes
COMMAND_SET_FREQUENCY = 0x01
COMMAND_SET_PRE_EMPHASIS = 0x04

# Define the serial port settings
BAUD_RATE = 19200
SERIAL_PORT = '/dev/ttyAMA0'  # Use the primary UART on GPIO pins

def send_command(ser_port, command, param1, param2):
    """
    Sends a command to the serial port.

    Args:
        ser_port (serial.Serial): The serial port instance.
        command (int): The command code.
        param1 (int): The first parameter.
        param2 (int): The second parameter.
    """
    command_string = bytes([command, param1, param2])
    print(f"Sending: {command_string.hex()}")
    ser_port.write(command_string)
    response = ser_port.read(1)  # Read the response byte

    if response == b'\x80':
        parameters = ser_port.read(2)
        print("Command succeeded. Parameters:", parameters.hex())
    else:
        print("Command failed.")

def calculate_bytes_for_frequency(frequency, ser_port):
    """
    Calculates the byte values for the given frequency and sends the set frequency command.

    Args:
        frequency (float): The frequency in MHz.
        ser_port (serial.Serial): The serial port instance.
    """
    value = int(frequency * 10 ** 6 / 10 ** 4)
    d0 = value // 256
    d1 = value % 256
    send_command(ser_port, COMMAND_SET_FREQUENCY, d0, d1)

def set_pre_emphasis(ser_port, d0):
    """
    Sets the pre-emphasis value.

    Args:
        ser_port (serial.Serial): The serial port instance.
        d0 (int): The pre-emphasis value.
    """
    send_command(ser_port, COMMAND_SET_PRE_EMPHASIS, d0, 0x00)

if __name__ == "__main__":
    # Parse command line arguments
    parser = argparse.ArgumentParser(description='Set frequency and pre emphasis')
    parser.add_argument('frequency', type=float, help='Frequency in MHz')
    parser.add_argument('--emphasis', type=int, default=1, help='Pre emphasis value (default: 1)')
    args = parser.parse_args()

    # Open the serial port
    with serial.Serial(SERIAL_PORT, BAUD_RATE, timeout=1) as ser:
        # Calculate bytes for frequency and set frequency
        calculate_bytes_for_frequency(args.frequency, ser)
        # Set pre emphasis
        set_pre_emphasis(ser, args.emphasis)