硬件：ESP32，DS18B20测温模块
软件：MicroPython，Thonny，EMQX
软件环境搭建和硬件接线可直接参考王铭东 老师的教程Thonny+MicroPython+ESP32开发环境搭建
效果图：
MQTT汇报温度.py
改好WIFI链接信息和MQTT服务器信息即可。
import timeimport networkfrom umqttsimple import MQTTClientfrom machine import Pinimport onewire, ds18x20# MQTT配置信息mqtt_client_id = ''mqtt_server_ip = ''mqtt_server_port = ''mqtt_topic = ''# 温度传感器初始化ds_pin = Pin(13)ds_sensor = ds18x20.DS18X20(onewire.OneWire(ds_pin))roms = ds_sensor.scan()print('发现设备: ', roms)# 获取当前温度def read_ds_sensor():ds_sensor.convert_temp()for rom in roms:temp = ds_sensor.read_temp(rom)if isinstance(temp, float):temp = round(temp, 2)return tempreturn 0# 链接WIFI联网def wifi():wlan = network.WLAN(network.STA_IF)wlan.active(True)if not wlan.isconnected():print('connecting to network...')wlan.connect('嘉然今天吃向晚', '12345678')i = 1while not wlan.isconnected():print("正在链接...{}".format(i))i += 1time.sleep(1)print('network config:', wlan.ifconfig())# MQTT建立链接def mqtt_init():# 建立一个MQTT客户端mqtt_client = MQTTClient(mqtt_client_id, mqtt_server_ip, mqtt_server_port)# 设置回调函数# mqtt_client.set_callback(mqtt_sub)# 建立连接mqtt_client.connect()# 监控ledctl这个通道，接收控制命令# mqtt_client.subscribe(mqtt_topic)return mqtt_client# MQTT回调函数，收到服务器消息后会调用这个函数def mqtt_sub(topic, msg): print('收到服务器信息')print(topic, msg)wifi()mqtt_client = mqtt_init()while True:current_temp = str(read_ds_sensor())print('当前温度：' + current_temp)mqtt_client.publish(mqtt_topic, current_temp)time.sleep(5)
umqttsimple.py
import usocket as socketimport ustruct as structfrom ubinascii import hexlifyclass MQTTException(Exception):passclass MQTTClient:def __init__(self,client_id,server,port=0,user=None,password=None,keepalive=0,ssl=False,ssl_params={},):if port == 0:port = 8883 if ssl else 1883self.client_id = client_idself.sock = Noneself.server = serverself.port = portself.ssl = sslself.ssl_params = ssl_paramsself.pid = 0self.cb = Noneself.user = userself.pswd = passwordself.keepalive = keepaliveself.lw_topic = Noneself.lw_msg = Noneself.lw_qos = 0self.lw_retain = Falsedef _send_str(self, s):self.sock.write(struct.pack("!H", len(s)))self.sock.write(s)def _recv_len(self):n = 0sh = 0while 1:b = self.sock.read(1)[0]n |= (b & 0x7F) << shif not b & 0x80:return nsh += 7def set_callback(self, f):self.cb = fdef set_last_will(self, topic, msg, retain=False, qos=0):assert 0 <= qos <= 2assert topicself.lw_topic = topicself.lw_msg = msgself.lw_qos = qosself.lw_retain = retaindef connect(self, clean_session=True):self.sock = socket.socket()addr = socket.getaddrinfo(self.server, self.port)[0][-1]self.sock.connect(addr)if self.ssl:import usslself.sock = ussl.wrap_socket(self.sock, **self.ssl_params)premsg = bytearray(b"\x10\0\0\0\0\0")msg = bytearray(b"\x04MQTT\x04\x02\0\0")sz = 10 + 2 + len(self.client_id)msg[6] = clean_session << 1if self.user is not None:sz += 2 + len(self.user) + 2 + len(self.pswd)msg[6] |= 0xC0if self.keepalive:assert self.keepalive < 65536msg[7] |= self.keepalive >> 8msg[8] |= self.keepalive & 0x00FFif self.lw_topic:sz += 2 + len(self.lw_topic) + 2 + len(self.lw_msg)msg[6] |= 0x4 | (self.lw_qos & 0x1) << 3 | (self.lw_qos & 0x2) << 3msg[6] |= self.lw_retain << 5i = 1while sz > 0x7F:premsg[i] = (sz & 0x7F) | 0x80sz >>= 7i += 1premsg[i] = szself.sock.write(premsg, i + 2)self.sock.write(msg)# print(hex(len(msg)), hexlify(msg, ":"))self._send_str(self.client_id)if self.lw_topic:self._send_str(self.lw_topic)self._send_str(self.lw_msg)if self.user is not None:self._send_str(self.user)self._send_str(self.pswd)resp = self.sock.read(4)assert resp[0] == 0x20 and resp[1] == 0x02if resp[3] != 0:raise MQTTException(resp[3])return resp[2] & 1def disconnect(self):self.sock.write(b"\xe0\0")self.sock.close()def ping(self):self.sock.write(b"\xc0\0")def publish(self, topic, msg, retain=False, qos=0):pkt = bytearray(b"\x30\0\0\0")pkt[0] |= qos << 1 | retainsz = 2 + len(topic) + len(msg)if qos > 0:sz += 2assert sz < 2097152i = 1while sz > 0x7F:pkt[i] = (sz & 0x7F) | 0x80sz >>= 7i += 1pkt[i] = sz# print(hex(len(pkt)), hexlify(pkt, ":"))self.sock.write(pkt, i + 1)self._send_str(topic)if qos > 0:self.pid += 1pid = self.pidstruct.pack_into("!H", pkt, 0, pid)self.sock.write(pkt, 2)self.sock.write(msg)if qos == 1:while 1:op = self.wait_msg()if op == 0x40:sz = self.sock.read(1)assert sz == b"\x02"rcv_pid = self.sock.read(2)rcv_pid = rcv_pid[0] << 8 | rcv_pid[1]if pid == rcv_pid:returnelif qos == 2:assert 0def subscribe(self, topic, qos=0):assert self.cb is not None, "Subscribe callback is not set"pkt = bytearray(b"\x82\0\0\0")self.pid += 1struct.pack_into("!BH", pkt, 1, 2 + 2 + len(topic) + 1, self.pid)# print(hex(len(pkt)), hexlify(pkt, ":"))self.sock.write(pkt)self._send_str(topic)self.sock.write(qos.to_bytes(1, "little"))while 1:op = self.wait_msg()if op == 0x90:resp = self.sock.read(4)# print(resp)assert resp[1] == pkt[2] and resp[2] == pkt[3]if resp[3] == 0x80:raise MQTTException(resp[3])return# Wait for a single incoming MQTT message and process it.# Subscribed messages are delivered to a callback previously# set by .set_callback() method. Other (internal) MQTT# messages processed internally.def wait_msg(self):res = self.sock.read(1)self.sock.setblocking(True)if res is None:return Noneif res == b"":raise OSError(-1)if res == b"\xd0": # PINGRESPsz = self.sock.read(1)[0]assert sz == 0return Noneop = res[0]if op & 0xF0 != 0x30:return opsz = self._recv_len()topic_len = self.sock.read(2)topic_len = (topic_len[0] << 8) | topic_len[1]topic = self.sock.read(topic_len)sz -= topic_len + 2if op & 6:pid = self.sock.read(2)pid = pid[0] << 8 | pid[1]sz -= 2msg = self.sock.read(sz)self.cb(topic, msg)if op & 6 == 2:pkt = bytearray(b"\x40\x02\0\0")struct.pack_into("!H", pkt, 2, pid)self.sock.write(pkt)elif op & 6 == 4:assert 0# Checks whether a pending message from server is available.# If not, returns immediately with None. Otherwise, does# the same processing as wait_msg.def check_msg(self):self.sock.setblocking(False)return self.wait_msg()
