from machine import Pin, I2C,Timer,PWM
import machine
import ssd1306
import network
import time
import dht
import ujson
from umqtt.simple import MQTTClient
# ESP32 Pin assignment
i2c = I2C(0, scl=Pin(22), sda=Pin(21))
oled_width = 128
oled_height = 64
oled = ssd1306.SSD1306_I2C(oled_width, oled_height, i2c)
oled.text('zhangrou', 10, 10)
# oled.text('temp', 10, 20)
# oled.text('humidity', 10, 30)
oled.show()
# MQTT Server Parameters
MQTT_CLIENT_ID = "zhangrou2306023126qwer"
MQTT_BROKER = "broker.emqx.io"
MQTT_USER = ""
MQTT_PASSWORD = ""
MQTT_TOPIC = "zhangrou2306023126"
TOPIC1 = b"ledctl2306023126" #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"pwmled2306023126"
TOPIC3 = b"ledstatus2306023126"
prev_weather = ""
sensor = dht.DHT22(Pin(15))
# 选择gpio2引脚
led_blue = machine.PWM(machine.Pin(2), freq=1000) # 设置 GPIO2 为输出
led_blue.duty(1023)
d = dht.DHT22(Pin(15))
def f(t):
d.measure()
a = d.temperature()
b= d.humidity()
print('temperature: {:.1f} dC'.format(a))
print('humidity: {:.1f} %'.format(b))
oled.fill(0)
oled.text("zhangrou",10,10)
oled.text('temp: {:.1f} dc'.format(a),10,25)
oled.text('humidity: {:.1f} %'.format(b), 10, 35)
oled.show()
tim = Timer(-1)
tim.init(period=2000, mode=Timer.PERIODIC, callback=f)
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) #connect之后就需要马上订阅主题,才能收到mqtt服务器送过来的信息
client.subscribe(TOPIC2)
print("Connected!")
def sample_weather(V):
global prev_weather
print("Measuring weather conditions... ", end="")
sensor.measure()
message = ujson.dumps({
"temp": sensor.temperature(),
"humidity": sensor.humidity(),
})
if message != prev_weather:
print("Updated!")
print("Reporting to MQTT topic{}:{}".format(MQTT_TOPIC,message))
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)