v1.17.1 with ESP-8266 SoftUART support

class SoftUART - half-duplex serial communication

SoftUART implements the standard UART/USART half-duplex serial communications protocol.
Supported communication parameters are:

• 8 data bits,
• 1 stop bit,
• No parity,
• 1M-baud tested with nothing running in the background.

Initialization

from machine import SoftUART, Pin

uart = SoftUART(tx=Pin(2), rx=Pin(4))
uart.init(baudrate=9600, timeout=0)

Constructors

• class machine.SoftUART(tx=Pin(Tx), rx=Pin(Rx))
  • Tx - pin used for data transmission
  • Rx - pin used for data reception

Methods

• SoftUART.init(tx=Pin(Tx), rx=Pin(Rx), baudrate=9600, bits=8, parity=None, stop=1)
  Basically constructor without additional memory allocation.
  • Tx - pin used for data transmission
  • Rx - pin used for data reception
  • baudrate - data rate
  • bits - data bits (only 8 supported)
  • parity - data parity bit (only None supported)
  • stop - stop bits (only 1 supported)
• SoftUART.deinit()
  Frees memory.
• SoftUART.read(n)
• SoftUART.readline()
  Unreliable.
• SoftUART.readinto()
  Not tested.
• SoftUART.write(buf)

Stream API

SoftUART supports stream API (select.select, select.poll, etc.)

Changelog

• Changed API. Moved tx/rx to kwargs.

v1.17 with ESP-8266 SoftUART support

Software UART support for ESP-8266

• Adapted from dmascord,
• Added multiple instances support,
• See commit history for more info.

Examples

Read

# test suite for SoftUART

from machine import SoftUART, Pin
import time
import select

poll = select.poll()

s1 = SoftUART(Pin(2), Pin(4), baudrate=9600, timeout=0)  # tx=2 rx=4
s2 = SoftUART(Pin(0), Pin(5), baudrate=9600, timeout=0)  # tx=0 rx=5
poll.register(s1)
poll.register(s2)

print("polling...")

while True:
    read = poll.ipoll()

    for r, ev in read:
        if (ev & select.POLLIN) != 0:
            i = None
            if r is s1:
                i = "s1"
            else:
                i = "s2"
            print(i, r.read())

Write

# test suite for SoftUART

from machine import SoftUART, Pin
import time

s1 = SoftUART(Pin(2), Pin(4), baudrate=9600, timeout=0)  # tx=2 rx=4
s2 = SoftUART(Pin(0), Pin(5), baudrate=9600, timeout=0)  # tx=0 rx=5

while True:
    print("sending... ", end="")
    s1.write("Hello world s1\r\n")
    print("1, ", end="")
    s2.write("Hello world s2\r\n")
    print("2, done.")
    time.sleep(1)