UART_SerialBaudRate.py

import serial
import time
import re
import os

# Comprehensive list of baud rates
baud_rates = [
    300, 600, 1200, 2400, 4800, 9600, 14400, 19200, 28800, 38400,
    57600, 76800, 115200, 230400, 460800, 500000, 576000, 921600
]

# Serial port settings
port = '/dev/serial0'
timeout = 15  # Seconds to read data for each baud rate

# Patterns to detect readable output
patterns = [r'U-Boot', r'=>\s', r'login:', r'kernel', r'booting', r'root@']

def is_readable(data):
    """Check if data contains readable ASCII or specific patterns."""
    try:
        text = data.decode('ascii', errors='ignore')
        printable_ratio = sum(c.isprintable() for c in text) / len(text) if text else 0
        if printable_ratio > 0.7:  # At least 70% printable characters
            return True
        for pattern in patterns:
            if re.search(pattern, text, re.IGNORECASE):
                return True
        return False
    except:
        return False

# Ensure user has permissions
if os.geteuid() != 0:
    print("Run this script with sudo to access /dev/serial0")
    exit(1)

# Ensure output directory exists
output_dir = "baud_outputs"
os.makedirs(output_dir, exist_ok=True)

# Test each baud rate with power cycle prompt
for baud in baud_rates:
    print(f"\nPreparing to test baud rate: {baud}")
    print("Please power OFF the Device, wait 5 seconds, then power it ON.")
    input("Press Enter when the Device is powered ON...")
    print(f"Testing baud rate: {baud}")
    
    try:
        # Open serial port
        ser = serial.Serial(
            port=port,
            baudrate=baud,
            bytesize=serial.EIGHTBITS,
            parity=serial.PARITY_NONE,
            stopbits=serial.STOPBITS_ONE,
            timeout=1
        )
        
        # Read data for timeout seconds
        start_time = time.time()
        data = b''
        while time.time() - start_time < timeout:
            if ser.in_waiting:
                data += ser.read(ser.in_waiting)
            time.sleep(0.1)
        
        # Save output to file
        filename = f"{output_dir}/output_{baud}.log"
        with open(filename, 'wb') as f:
            f.write(data)
        
        # Check if output is readable
        if data and is_readable(data):
            print(f"Possible match at {baud} baud! Output saved to {filename}")
            try:
                print("Sample output:", data.decode('ascii', errors='ignore')[:200])
            except:
                print("Sample output (raw):", data[:200])
        else:
            print(f"No readable output at {baud} baud. Saved to {filename}")
        
        ser.close()
    except serial.SerialException as e:
        print(f"Error at {baud} baud: {e}")
    except Exception as e:
        print(f"Unexpected error at {baud} baud: {e}")

print(f"\nTesting complete. Check {output_dir}/output_*.log files for details.")
print(f"Use 'cat {output_dir}/output_*.log' or open files in a text editor.")
print("If a baud rate shows readable text, test it manually with:")
print("  minicom -b <baud_rate> -o -D /dev/serial0")