解决esp8266 Mircopython OTA 远程升级方案

        对于ESP8266的开发，在arduino平台上的开发库非常多，arduino上也可以找到esp8266 OTA的许多解决方案，最近突然对Mircopython好奇起来，想通过Mircopython写一下esp8266运行的程序，然后过程中查找了许多的资料都没有看到Mircopython平台上如何OTA升级esp8266固件，于是自己胡乱做了一个用起来还不错的替代方案，给爱好者们提供一个小小的参考思路，直接进入正题。

        我是使用uPyCraft烧录以及编辑代码的，下载uPyCraft链接: https://pan.baidu.com/s/1HARl7J3fy0J11I_FHG8fCg 提取码: 5u4k 

        第一次插入开发版会自动提示烧录Mircopython固件，选择好设置点击OK，或者通过菜单Tools→BurnFirmware进行烧录。

 用uPyCraft工具烧完成后，device文件夹为esp8266寄存器中的根目录，device目录下仅有一个boot.py文件，次文件为esp8266每次启动时必定执行一次的文件，随后上传simple.py以及index0.py文件，simple.py文件为MQTT连接库，可以在从目录uPy_lib/umqtt中直接找到拖拽到device目录。以下代码我也会全部给出。

 boot.py：

# This file is executed on every boot (including wake-boot from deepsleep)#import esp#esp.osdebug(None)import gcimport os#import webrepl#webrepl.start()gc.collect()base = "0"try:  file = open("base.ini","r")  base = file.read()  file.close()except:  file = open("base.ini","w")  file.write("0")  file.close()  if base == "1":  print("加载用户1。。。。")  try:    os.remove("index0.py")    print("删除用户0完成")  except:    print("删除用户0失败")  import index1  index1.connectWiFi()else :  print("加载用户0。。。。")  try:    os.remove("index1.py")    print("删除用户1完成")  except:    print("删除用户1失败")  import index0  index0.connectWiFi()

simple.py：

import usocket as socketimport ustruct as struct#from 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 1883    self.client_id = client_id    self.sock = None    self.addr = socket.getaddrinfo(server, port)[0][-1]    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  def _send_str(self, s):    self.sock.write(struct.pack("!H", len(s)))    self.sock.write(s)  def _recv_len(self):    n = 0    sh = 0    while 1:      b = self.sock.read(1)[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  def connect(self, clean_session=True):    self.sock = socket.socket()    self.sock.connect(self.addr)    if self.ssl:      import ussl      self.sock = ussl.wrap_socket(self.sock, **self.ssl_params)    msg = bytearray(b"/x10/0/0/x04MQTT/x04/x02/0/0")    msg[1] = 10 + 2 + len(self.client_id)    msg[9] = clean_session << 1    if self.user is not None:      msg[1] += 2 + len(self.user) + 2 + len(self.pswd)      msg[9] |= 0xC0    if self.keepalive:      assert self.keepalive < 65536      msg[10] |= self.keepalive >> 8      msg[11] |= self.keepalive & 0x00FF    if self.lw_topic:      msg[1] += 2 + len(self.lw_topic) + 2 + len(self.lw_msg)      msg[9] |= 0x4 | (self.lw_qos & 0x1) << 3 | (self.lw_qos & 0x2) << 3      msg[9] |= self.lw_retain << 5    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] == 0x02    if resp[3] != 0:      raise MQTTException(resp[3])    return resp[2] & 1  def 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 | 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, ":"))    self.sock.write(pkt, i + 1)    self._send_str(topic)    if qos > 0:      self.pid += 1      pid = self.pid      struct.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:            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, ":"))    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 None    if res == b"":      raise OSError(-1)    if res == b"/xd0":  # PINGRESP      sz = self.sock.read(1)[0]      assert sz == 0      return None    op = res[0]    if op & 0xf0 != 0x30:      return op    sz = 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 + 2    if op & 6:      pid = self.sock.read(2)      pid = pid[0] << 8 | pid[1]      sz -= 2    msg = 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()

index0.py：

import osimport time import networkfrom simple import MQTTClientimport machinefrom machine import Pin#wifissid="XXXXX"#WiFi名称passwd="XXXXXXXXX"#WiFi密码#mqttclient_id = "mricopython_"mserver = "XXXXX.com"#mqtt服务器IPport=1883M_subscribe = b"py"#设备订阅的主题M_subscribe_ota = M_subscribe + b"u"#设备订阅的OTA主题M_topic = M_subscribe + b"r"#设备推送消息的主题client = Nonewlan = Noneled=Pin(2, Pin.OUT)led2=Pin(5, Pin.OUT, value=1)def connectWiFi():  #连接WiFi  wlan = network.WLAN(network.STA_IF)  wlan.active(True)  if not wlan.isconnected():    print("connecting to network...")    wlan.connect(ssid, passwd)      while not wlan.isconnected():      pass  print("network config:", wlan.ifconfig())  connect_mqtt()#处理OTA版本信息def ota(txt):  file = open("base.ini","r")  base = file.read()  file.close()  if base == "1":    try:      f = open("index0.py","a")      f.write(txt)      f.close()          file = open("base.ini","w")      file.write("0")      file.close()      print("烧录用户0完毕，正在重启。。。")      machine.reset()     except:      print("烧录用户0错误")      pass  else:    try:          f = open("index1.py","a")      f.write(txt)      f.close()      file = open("base.ini","w")      file.write("1")      file.close()      print("烧录用户1完毕，正在重启。。。")      machine.reset()    except:      print("烧录用户1错误")      pass  #MQTT信息处理def sub_cb(topic_b, msg_b):  #转换格式后打印bytes.decode(),str.decode()  topic = bytes.decode(topic_b)  msg = bytes.decode(msg_b)  print(topic,":",msg)  # 判断MQTT信息作出相应动作  #string.spilt(" ")分组  if topic == bytes.decode(M_subscribe):    if msg=="1":      led.off()    if msg=="0":      led.on()  elif topic == bytes.decode(M_subscribe_ota):    ota(msg)    #连接MQTTdef connect_mqtt():   try:    t = str(time.ticks_us())    print("client:")    c = MQTTClient(client_id + t + str(time.ticks_us()),mserver)    c.set_callback(sub_cb)    c.connect()    c.subscribe(M_subscribe)#订阅信息主题    c.subscribe(M_subscribe_ota)#订阅OTA升级主题    print("连接MQTT成功，已订阅" + str(M_subscribe))    c.publish(M_topic,b"连接MQTT成功") #推送信息#主循环，程序在此做死循环    while True:      c.check_msg() #接收MQTT信息      #c.publish(M_topic,b"版本1") #推送信息  except:    print("重新连接MQTT")    connect_mqtt()if __name__ == "__main__":  connectWiFi()

思路是boot.py通过读取系统生成的base.ini里的内容判断需要加载用户0 “index0.py”或者是用户1  “index1.py”进行运行，升级代码通过mqtt传输到esp8266上，esp8266接受到自定义的OTA升级主题发送的代码后，通过判断base.ini生成新的index0.py或者index1.py，并删除旧的index.py。

        注意：升级代码通过mqtt传输时代码过长时需要进行分段发送，本代码仅演示未分段代码的升级过程。测试过程中发现MQTT.fx发送中文会乱码。