MicroPython的MQTT实现（asyncio协程版）
一、改自:umqtt.simple代码
https://github.com/micropython/micropython-lib/tree/master/umqtt.simple
二、免费MQTT测试服务器
https://www.emqx.cn/mqtt/public-mqtt5-broker
https://www.emqx.cn/mqtt/mqtt-websocket-toolkit
三、源代码（lib\umqtt\cw_simple.py）
import ustruct as struct
import uasyncio as asyncio
from ubinascii import hexlify
import ussl as ssl
class MQTTException(Exception):
pass
class 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 1883
self.client_id = client_id
self.server = server
self.port = port
self.ssl = ssl
self.ssl_params = ssl_params
self.pid = 0
self.cb = None
self.user = user
self.pswd = password
self.keepalive = keepalive
self.lw_topic = None
self.lw_msg = None
self.lw_qos = 0
self.lw_retain = False
self.r = None
self.w = None
async def _recv_bytes(self, bytes_len):
bs = await self.r.read(bytes_len)
return bs
async def _send_bytes(self, bytes_data, bytes_len=None):
if bytes_len == None:
self.w.write(bytes_data)
else:
self.w.write(bytes_data[0:bytes_len])
await self.w.drain()
async def _send_str(self, s):
await self._send_bytes(struct.pack("!H", len(s)))
await self._send_bytes(s)
async def _recv_len(self):
n = 0
sh = 0
while 1:
bn = await self._recv_bytes(1)
b = bn[0]
n |= (b & 0x7f) << sh
if not b & 0x80:
return n
sh += 7
def set_callback(self, f):
self.cb = f
def set_last_will(self, topic, msg, retain=False, qos=0):
assert 0 <= qos <= 2
assert topic
self.lw_topic = topic
self.lw_msg = msg
self.lw_qos = qos
self.lw_retain = retain
async def connect(self, clean_session=True):
self.r, self.w = await asyncio.open_connection(host=self.server, port=self.port)
if self.ssl:
ssl_context = ssl.create_default_context(ssl.Purpose.CLIENT_AUTH)
ssl_context.check_hostname = False
ssl_context.load_default_certs()
self.r, self.w = await asyncio.open_connection(host=self.server, port=self.port, ssl=ssl_context)
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 << 1
if self.user is not None:
sz += 2 + len(self.user) + 2 + len(self.pswd)
msg[6] |= 0xC0
if self.keepalive:
assert self.keepalive < 65536
msg[7] |= self.keepalive >> 8
msg[8] |= self.keepalive & 0x00FF
if 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) << 3
msg[6] |= self.lw_retain << 5
i = 1
while sz > 0x7f:
premsg[i] = (sz & 0x7f) | 0x80
sz >>= 7
i += 1
premsg[i] = sz
await self._send_bytes(premsg, i + 2)
await self._send_bytes(msg)
#print(hex(len(msg)), hexlify(msg, ":"))
await self._send_str(self.client_id)
if self.lw_topic:
await self._send_str(self.lw_topic)
await self._send_str(self.lw_msg)
if self.user is not None:
await self._send_str(self.user)
await self._send_str(self.pswd)
resp = await self._recv_bytes(4)
assert resp[0] == 0x20 and resp[1] == 0x02
if resp[3] != 0:
raise MQTTException(resp[3])
return resp[2] & 1
async def disconnect(self):
await self._send_bytes(b"\xe0\0")
self.w.close()
await self.w.wait_closed()
async def ping(self):
await self._send_bytes(b"\xc0\0")
async def publish(self, topic, msg, retain=False, qos=0):
pkt = bytearray(b"\x30\0\0\0")
pkt[0] |= qos << 1 | retain
sz = 2 + len(topic) + len(msg)
if qos > 0:
sz += 2
assert sz < 2097152
i = 1
while sz > 0x7f:
pkt[i] = (sz & 0x7f) | 0x80
sz >>= 7
i += 1
pkt[i] = sz
#print(hex(len(pkt)), hexlify(pkt, ":"))
await self._send_bytes(pkt, i + 1)
await self._send_str(topic)
if qos > 0:
self.pid += 1
pid = self.pid
struct.pack_into("!H", pkt, 0, pid)
await self._send_bytes(pkt, 2)
await self._send_bytes(msg)
if qos == 1:
while 1:
op = await self.wait_msg()
if op == 0x40:
sz = await self._recv_bytes(1)
assert sz == b"\x02"
rcv_pid = await self._recv_bytes(2)
rcv_pid = rcv_pid[0] << 8 | rcv_pid[1]
if pid == rcv_pid:
return
elif qos == 2:
assert 0
def 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 += 1
struct.pack_into("!BH", pkt, 1, 2 + 2 + len(topic) + 1, self.pid)
#print(hex(len(pkt)), hexlify(pkt, ":"))
await self._send_bytes(pkt)
await self._send_str(topic)
await self._send_bytes(qos.to_bytes(1, "little"))
while 1:
op = await self.wait_msg()
if op == 0x90:
resp = await self._recv_bytes(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 = await self._recv_bytes(1)
if res is None:
return None
if res == b"":
print("res is empty!")
#raise OSError(-1)
return None
if res == b"\xd0": # PINGRESP
sz_n = await self._recv_bytes(1)
sz = sz_n[0]
print('sz = {0}'.format(sz))
assert sz == 0
return None
op = res[0]
if op & 0xf0 != 0x30:
return op
sz = await self._recv_len()
topic_len = await self._recv_bytes(2)
topic_len = (topic_len[0] << 8) | topic_len[1]
topic = await self._recv_bytes(topic_len)
sz -= topic_len + 2
if op & 6:
pid = await self._recv_bytes(2)
pid = pid[0] << 8 | pid[1]
sz -= 2
msg = await self._recv_bytes(sz)
await self.cb(topic, msg)
if op & 6 == 2:
pkt = bytearray(b"\x40\x02\0\0")
struct.pack_into("!H", pkt, 2, pid)
await self._send_bytes(pkt)
elif op & 6 == 4:
assert 0
return op
四、源代码（test_mqtt.py）
import ujson
import time
import dht
from machine import Pin, ADC, Timer
import uasyncio as asyncio
from umqtt.cw_simple import MQTTClient
class MyIotPrj:
def __init__(self):
client_id = "slim_id"
self.mserver = 'broker.emqx.io'
port = 1883
self.client = MQTTClient(client_id, self.mserver, 0)
self.isconn = False
self.topic_ctl = b'demo_ctl'
self.topic_sta = b'demo_sta'
async def sub_callback(self, topic, msg):
print((topic, msg))
async def mqtt_main_thread(self):
try:
self.client.set_callback(self.sub_callback)
conn_ret_code = await self.client.connect()
if conn_ret_code != 0:
return
print('conn_ret_code = {0}'.format(conn_ret_code))
await self.client.subscribe(self.topic_ctl)
print("Connected to %s, subscribed to %s topic" % (self.mserver, self.topic_ctl))
self.isconn = True
while True:
await self.client.wait_msg()
await asyncio.sleep(1)
print('wait_msg')
finally:
if self.client is not None:
print('off line')
await self.client.disconnect()
self.isconn = False
async def mqtt_upload_thread(self):
# my_dht = dht.DHT11(Pin(14, Pin.IN))
dht_data = {
'temperature':0,
'humidity':0
}
while True:
if self.isconn == True:
# my_dht.measure()
# dht_data['temperature'] = my_dht.temperature()
# dht_data['humidity'] = my_dht.humidity()
print(dht_data)
await self.client.publish(self.topic_sta, ujson.dumps(dht_data), retain=True)
await asyncio.sleep(1)
while True:
if self.isconn == True:
await self.client.ping()
await asyncio.sleep(5)
def main():
mip = MyIotPrj()
loop = asyncio.get_event_loop()
loop.create_task(mip.mqtt_main_thread())
loop.create_task(mip.mqtt_upload_thread())
loop.run_forever()
if __name__ == '__main__':
main()