UART

[FrankHenckens]

Hello, I am trying to use an antenna to scan a LF RFID chip. I'm using UART to communicate with the reader via an RS-232 module. When I write to UART and when I read, I get the same bytearray. I don't understand why I get the same information. All help is welcome!

from machine import UART, Pin
import utime

uart = UART(0, baudrate=9600, tx=Pin(0), rx=Pin(1))

def send_command(command):
    bcc = 0  
    for byte in command:
        bcc ^= byte    
    uart.write(command) 
    print(f"Command sent: {command}")

def select_antenna_1():
    command = bytearray([0x04, 0xF2, 0xA0, 0x01, 0x57])  
    send_command(command)

def confirm_antenna_selection():
    print("Wachten op bevestiging van antenneselectie...")
    utime.sleep(1)  

    if uart.any():
        response = uart.read()  
        print(f"Response antenne ontvangen: {response}")
        return True

    else:
        print("Geen respons ontvangen na antenneselectie.")
        return False

def read_iso_tag():
    command = bytearray([0x03, 0xEA, 0x53, 0xBA])  
    send_command(command)
    utime.sleep(2)  
    if uart.any():
        response = uart.read()
        print(f"Tag data ontvangen (bytes): {[hex(byte) for byte in response]}") 
        
        if len(response) > 1:
            tag_id = int.from_bytes(response[1:5], 'big')  
            print(f"Tagnummer: {tag_id}")
        else:
            print("Ongeldige tagdata ontvangen.")
    else:
        print("Geen tag gelezen.")

while True:
    print("Antenne 1 selecteren...")
    select_antenna_1()
    utime.sleep(3)

    print("Bevestigen van antenneselectie...")
    if confirm_antenna_selection():
        print("ISO 11784/11785 tag proberen te lezen...")
        read_iso_tag()  
    else:
        print("Antenne selectie mislukt.")
    utime.sleep(5)

[robert-hh]

Obviously the data you send is echoed by the RF-ID device or the RS232 module. Which RS232 module do you use and how is it wired? Tell all wires.

[bidrohini]

You can check if the RFID reader is echoing the commands by printing what you receive immediately after sending a command.