解决esp8266 Mircopython OTA 远程升级方案

Posted 2021-10-18 潭影

        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 gc
import 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 socket
import ustruct as struct
#from ubinascii import hexlify

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.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 os
import time 
import network
from simple import MQTTClient
import machine
from machine import Pin

#wifi
ssid='XXXXX'#WiFi名称
passwd='XXXXXXXXX'#WiFi密码

#mqtt
client_id = "mricopython_"
mserver = 'XXXXX.com'#mqtt服务器IP
port=1883
M_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 = None
wlan = None
led=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MQTT
def 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。