"""
MicroPython IoT Weather Station Example for Wokwi.com
To view the data:
1. Go to http://www.hivemq.com/demos/websocket-client/
2. Click "Connect"
3. Under Subscriptions, click "Add New Topic Subscription"
4. In the Topic field, type "wokwi-weather" then click "Subscribe"
Now click on the DHT22 sensor in the simulation,
change the temperature/humidity, and you should see
the message appear on the MQTT Broker, in the "Messages" pane.
Copyright (C) 2022, Uri Shaked
https://wokwi.com/arduino/projects/322577683855704658
"""
import network
import time
from machine import Pin,I2C
import machine
import dht
import ujson
from umqtt.simple import MQTTClient
import ssd1306
from machine import Timer
# MQTT Server Parameters
MQTT_CLIENT_ID = "hongyuhao2206055030"
MQTT_BROKER = "broker.emqx.io"
MQTT_USER = ""
MQTT_PASSWORD = ""
MQTT_TOPIC = "hongyuhao2206055030"
sensor = dht.DHT22(Pin(15))
i2c = I2C(0, scl=Pin(22), sda=Pin(21))
oled_width = 128
oled_height = 64
oled = ssd1306.SSD1306_I2C(oled_width, oled_height, i2c)
TOPIC1 = b"ledctl2206055030" #灯控主题,为了避免主题和其他同学一样,末尾需要添加自己的学号
TOPIC2 = b"pwmled2206055030"
TOPIC3 = b"ledstatus2206055030"
prev_weather = ""
sensor = dht.DHT22(Pin(15))
led_blue = machine.PWM(machine.Pin(2), freq=1000) # 设置 GPIO2 为输出
led_blue.duty(1)
#oled.text('Hello, Wokwi!', 10, 10)
#oled.show()
print("Connecting to WiFi", end="")
sta_if = network.WLAN(network.STA_IF)
sta_if.active(True)
sta_if.connect('Wokwi-GUEST', '')
while not sta_if.isconnected():
print(".", end="")
time.sleep(0.1)
print(" Connected!")
def sub_cb(topic, msg): #定义收到mqtt主题信息之后的回调函数
global pwm_old, pwmval
if topic == TOPIC1:
print((topic, msg))
if msg == b"on":
pwmval = 0
led_blue.duty(pwmval)
elif msg == b"off":
pwmval = 1023;
led_blue.duty(pwmval)
if topic == TOPIC2:
pwmval = int(((100 - int(msg)) / 100) * 1023)
if pwmval>1023 : pwmval=1023
if pwmval<0: pwmval=0
print((topic, pwmval))
led_blue.duty(pwmval)
print("Connecting to MQTT server... ", end="")
client = MQTTClient(MQTT_CLIENT_ID, MQTT_BROKER, user=MQTT_USER, password=MQTT_PASSWORD)
client.set_callback(sub_cb)
client.connect()
client.subscribe(TOPIC1)
client.subscribe(TOPIC2)
print("Connected!")
def sample_weather(V):
global prev_weather
print("Measuring weather conditions... ", end="")
sensor.measure()
msg_data={
"temp": sensor.temperature(),
"humidity": sensor.humidity(),
}
message=ujson.dumps(msg_data)
if message != prev_weather:
print("Updated!")
print("Reporting to MQTT topic {}: {}".format(MQTT_TOPIC, message))
oled.fill(0)
oled.text('hongyuhao',10,10)
oled.text('temp:%.1f'%(msg_data["temp"]),10,30)
oled.text('humidity:%.1f'%(msg_data["humidity"]),10,50)
oled.show()
client.publish(MQTT_TOPIC, message)
prev_weather = message
else:
print("No change")
tim = Timer(-1)
tim.init(period=5000, mode=Timer.PERIODIC, callback=sample_weather)
while True:
client.wait_msg()
time.sleep(1)