Arduino/esp8266/eproj2/ex2.py

import time
import machine
import onewire, ds18x20
import ujson as json
import ubinascii
from umqtt.simple import MQTTClient

class TempMon:


	def __init__(self, pin):
		self.cfg = {
		    "broker": "192.168.1.153",
		    "sensor_pin": 5, 
		    "client_id": b"esp8266_" + ubinascii.hexlify(machine.unique_id()),
		    "topic": b"sensor_data",
		}
		self.load_config()
		dat = machine.Pin(self.cfg['sensor_pin'])
		# create the onewire object
		self.ds = ds18x20.DS18X20(onewire.OneWire(dat))
		# scan for devices on the bus
		self.roms = self.ds.scan()
		time.sleep_ms(750)
		print('found devices:', self.roms)
		self.client = MQTTClient(self.cfg['client_id'], self.cfg['broker'])
		self.client.connect()
		print("Connected to {}".format(self.cfg['broker']))

	def load_config(self):
	    try:
		with open("/config.json") as f:
			config = json.loads(f.read())
	    except (OSError, ValueError):
       		 print("Couldn't load /config.json")
       		 self.save_config()
	    else:
       		self.cfg.update(config)
	        print("Loaded config from /config.json")

	def save_config(self):
	    try:
	        with open("/config.json", "w") as f:
			f.write(json.dumps(self.cfg))
	    except OSError:
		print("Couldn't save /config.json")




# loop 10 times and print all temperatures
	def read_temp(self):
		for i in range(10):
		    try:
			    print('temperatures:', end=' ')
			    self.ds.convert_temp()
			    time.sleep_ms(750)
			    for rom in self.roms:
			        val = self.ds.read_temp(rom)
			        s_val = 'Device %s reading :%s' % (str(rom), val)
			 	print(s_val)		
				self.client.publish(self.cfg['topic'], bytes(s_val, 'utf-8'))
			    print()
		    except Exception:
			    print("error encountered...continuing")
			    continue