import time
from ds18x20 import DS18X20
from homie.node import HomieNode
from homie.property import HomieNodeProperty
from homie.constants import FLOAT
from machine import Pin
from onewire import OneWire
from uasyncio import get_event_loop, sleep_ms
class DS18B20(HomieNode):
def __init__(self, name="One Wire DS18B20", pin=12, interval=10, pull=-1):
super().__init__(id="ds18b20", name=name, type="ds18b20")
self.ds18b20 = DS18X20(OneWire(Pin(pin)))
addrs = self.ds18b20.scan()
if not addrs:
raise Exception("no DS18B20 found at bus on pin %d" % pin)
# save what should be the only address found
self.addr = addrs.pop()
self.temperature = 0
self.interval = interval
self.temp_property = HomieNodeProperty(
id="temperature",
name="Temperature",
datatype=FLOAT,
format="-40:80",
unit="°F",
)
self.add_property(self.temp_property)
loop = get_event_loop()
loop.create_task(self.update_data())
async def update_data(self):
delay = self.interval * 1000
while True:
self.temperature = self.read_temp()
self.temp_property.data = self.temperature
await sleep_ms(delay)
def read_temp(self, fahrenheit=True):
"""
Reads temperature from a single DS18X20
:param fahrenheit: Whether or not to return value in Fahrenheit
:type fahrenheit: bool
:return: Temperature
:rtype: float
"""
self.ds18b20.convert_temp()
time.sleep_ms(750)
temp = self.ds18b20.read_temp(self.addr)
if fahrenheit:
ntemp = temp
print("Temp: " + str(self.c_to_f(ntemp)))
return self.c_to_f(ntemp)
return temp
@staticmethod
def c_to_f(c):
"""
Converts Celsius to Fahrenheit
:param c: Temperature in Celsius
:type c: float
:return: Temperature in Fahrenheit
:rtype: float
"""
return (c * 1.8) + 32
def main():
homie = HomieDevice(settings)
homie.add_node(DS18B20())
homie.run_forever()
if __name__ == "__main__":
main()
