onewire — interface to a 1-wire serial bus

The 1-wire bus is a serial bus that uses just a single wire for communication (in addition to wires for ground and power).

This module provides low level access to the 1-wire serial interface. Other modules dht, ds18x20 and neopixel make use of this module.

Read about the 1-wire communications protocol at https://en.wikipedia.org/wiki/1-Wire

Class OneWire

Example Usage:

# For the following code to work you need to have at least one DS18B20 temperature sensor with its data line connected to Pin P1.
import onewire, time, ds18x20
from machine import Pin
import onewire, ds18x20

# create the onewire object
ds = ds18x20.DS18X20(onewire.OneWire(Pin('P1')))

# scan for devices on the bus
roms = ds.scan()
print('found devices:', roms)

# loop 10 times and print all temperatures
for i in range(10):
    print('temperatures:', end=' ')
    ds.convert_temp()
    time.sleep_ms(750)
    for rom in roms:
        print(ds.read_temp(rom), end=' ')
    print()

OneWire Constructor

class onewire.OneWire(pin)

pin is a Pin object using one of the Kookaberry’s input pins (e.g. P1, P2, P3A, P3B, P4, P5)

OneWire Methods

OneWire.reset(required=False)

Resets the 1-wire bus to its initial conditions and returns the boolean success status.

Returns true if a device presence pulse was detected, otherwise false.

required defaults to False, but if set to True will raise a OneWireError if the reset is unsuccessful.

OneWire.readbit()

Reads and returns a single bit from 1-wire bus, assuming the 1-wire protocol.

OneWire.readbyte()

Reads 8 bits from the 1-wire bus using the 1-wire protocol, then returns them as an integer. (Assumes a low-bit-first model.)

OneWire.readinto(bytearray)

Reads bytes from the 1-wire bus using the 1-wire protocol, into a predefined byte array buffer, until the buffer is filled.

bytearray is a byte array of program-defined length.

OneWire.writebit(bitvalue)

Writes a single bit with value bitvalue to the 1-wire bus, using the 1-wire protocol.

OneWire.writebyte(bytevalue)

From byte bytevalue, writes 8 bits to the 1-wire bus using the 1-wire protocol. (Assumes a low-bit-first model.)

OneWire.write(bytearray)

Writes the contents of the bytearray to the 1-wire bus using the 1-wire protocol.

OneWire.select_rom(romcode)

Selects a specific 1-wire device by specifying its unique romcode.

OneWire.scan()

Scans the 1-wire bus and returns an array of unique *romcode*s corresponding to the devices on the 1-wire bus.

OneWire.crc8(bytearray)

Computes the 8-bit CRC-remainder of the given bytearray (or other buffered object) using the CRC-8/MAXIM version.