Atomic RS232 Base

AtomRS232 Class provides a set of methods to control the RS232 module. Through the UART interface, the module can transmit and receive data, supporting various baud rates and flow control configurations.

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UiFlow2 Example

RS232 Example

Open the atoms3r_rs232_example.m5f2 project in UiFlow2.

This example demonstrates how to send and receive data using the RS232 module via the UART interface.

UiFlow2 Code Block:

Example output:

None

MicroPython Example

RS232 Example

This example demonstrates how to send and receive data using the RS232 module via the UART interface.

MicroPython Code Block:

# SPDX-FileCopyrightText: 2025 M5Stack Technology CO LTD
#
# SPDX-License-Identifier: MIT

import os, sys, io
import M5
from M5 import *
from base import AtomRS232


base_rs232 = None


def setup():
    global base_rs232

    M5.begin()
    base_rs232 = AtomRS232(
        2,
        baudrate=115200,
        bits=8,
        parity=None,
        stop=1,
        tx=5,
        rx=6,
        txbuf=256,
        rxbuf=256,
        timeout=0,
        timeout_char=0,
        invert=0,
        flow=0,
    )


def loop():
    global base_rs232
    M5.update()
    if BtnA.wasPressed():
        print("hello M5")
        base_rs232.write("hello M5")
    if base_rs232.any():
        print(base_rs232.read())


if __name__ == "__main__":
    try:
        setup()
        while True:
            loop()
    except (Exception, KeyboardInterrupt) as e:
        try:
            from utility import print_error_msg

            print_error_msg(e)
        except ImportError:
            print("please update to latest firmware")

Example output:

None

API

AtomRS232

class base.rs232.AtomRS232(id, **kwargs)

Bases: object

init(baudrate=9600, bits=8, parity=None, stop=1, *, ...)

Initialize the UART bus with the given parameters.

Parameters:

• baudrate (int) – The clock rate for the UART communication.

• bits (int) – Number of bits per character (7, 8, or 9).

• parity (int) – Parity setting, either None, 0 (even), or 1 (odd).

• stop (int) – Number of stop bits (1 or 2).

UiFlow2 Code Block:

MicroPython Code Block:

rs232_0.init(baudrate=115200, bits=8, parity=None, stop=1)

deinit()

Turn off the UART bus.

UiFlow2 Code Block:

MicroPython Code Block:

rs232_0.deinit()

any()

Returns the number of characters that can be read without blocking.

Returns:

The number of available bytes.

Return type:

int

UiFlow2 Code Block:

MicroPython Code Block:

rs232_0.any()

read([nbytes])

Read characters from the UART buffer.

Parameters:

nbytes (int) – The maximum number of bytes to read (optional).

Returns:

A bytes object containing the data read.

Return type:

bytes

UiFlow2 Code Block:

MicroPython Code Block:

data = rs232_0.read()

readinto(buf[, nbytes])

Read bytes into the buf. If nbytes is specified, read at most that many bytes; otherwise, read at most len(buf) bytes. It may return sooner if a timeout is reached. The timeout is configurable in the constructor.

Parameters:

• buf (bytearray) – The buffer into which the bytes will be read.

• nbytes (int) – (Optional) The maximum number of bytes to read.

Returns:

The number of bytes read and stored into buf, or None if a timeout occurs.

Return type:

int or None

UiFlow2 Code Block:

MicroPython Code Block:

data = bytearray(10)
num_bytes = rs232_0.readinto(data)
num_bytes = rs232_0.readinto(data, 5)

readline()

Read a line ending in a newline character. It may return sooner if a timeout is reached. The timeout is configurable in the constructor.

Returns:

The line read as bytes, or None if a timeout occurs.

Return type:

bytes or None

UiFlow2 Code Block:

MicroPython Code Block:

line = rs232_0.readline()

write(buf)

Write data to the UART interface.

Parameters:

buf (bytes) – The data to be written.

Returns:

The number of bytes written.

Return type:

int

UiFlow2 Code Block:

MicroPython Code Block:

rs232_0.write(b'Hello')

sendbreak()

Send a break condition on the bus. This drives the bus low for a duration longer than required for a normal transmission of a character.

Returns:

None

UiFlow2 Code Block:

MicroPython Code Block:

rs232_0.sendbreak()

flush()

Waits until all data has been sent. In case of a timeout, an exception is raised. The timeout duration depends on the TX buffer size and the baud rate. Unless flow control is enabled, a timeout should not occur.

Returns:

None

UiFlow2 Code Block:

MicroPython Code Block:

rs232_0.flush()

txdone()

Check whether all data has been sent or no data transfer is happening. Returns True if no transmission is ongoing, otherwise returns False.

Returns:

True if no data transfer is happening, otherwise False.

Return type:

bool

UiFlow2 Code Block:

MicroPython Code Block:

status = rs232_0.txdone()