example_rs485_echo.py

'''
Exo Sense RP example: using the RS-485 interface

Simple example that echoes back the received text lines through
Exo Sense RP's RS-485 interface (connected to the RP2040's UART)

Copyright (C) 2022 Sfera Labs S.r.l. - All rights reserved.

For information, see:
http://www.sferalabs.cc/

This code is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
See file LICENSE.txt for further informations on licensing terms.
'''

import exosense as exo

# initialize the port with given baudrate and timeouts
exo.RS485.init(baudrate=9600, timeout=500, timeout_char=100)

# Unset TX-enable line to get ready to receive data
exo.RS485.txen(False)

while True:
    line = exo.RS485.readline()
    if line:
        exo.RS485.txen(True) # Set TX-enable line before sending response
        exo.RS485.write("Echo: ")
        exo.RS485.write(line)
        exo.RS485.txen(False)