微信小程序对接串口摄像头

串口摄像头由树莓派控制，代码如下：

# _*_ coding:utf-8
import serial
import time
import traceback
import pycurl
import requests
import io
import json
import base64

ser = serial.Serial("/dev/ttyAMA0",115200)
print(ser.name)
print(ser.port)

f=None

def main():
    print("main:")
    res0 = setResolution()
    res0 = reset()
    print(res0)
    while True: 
        try:
            res1=stopCurrent()
            print(res1)

            res2=getCurrentLength()
            print(res2)
    
            hBit = res2[7]<<8
            lBit = res2[8]
            imageSize = hBit+lBit;
            dataSize = imageSize+10
            print(imageSize)

            res3=getCurrentImage(res2[7],res2[8],dataSize)
            imageData = res3[5:(dataSize-5)]
    

            f = open('/home/pi/Camera/image.jpg','wb')
            for i in range(len(imageData)):
                f.write(chr(imageData[i]))
            f.close

            resumCurrent()
            upload()
        except Exception:
            print(traceback.print_exc())

def setResolution():
    bitarray = [0x56,0x00,0x31,0x05,0x04,0x01,0x00,0x19,0x11]
    ser.write(bitarray)
    time.sleep(0.1)
    index=0
    resp=[]
    while True:
        s = ser.read()
        if s!=None:
            index = index+1
            resp.append(ord(s))
        if index>=5:
            break;
    return resp  
def setCompress():
    bitarray = [0x56,0x00,0x31,0x05,0x01,0x01,0x12,0x04,0x36]
    ser.write(bitarray)
    time.sleep(0.1)
    index=0
    resp=[]
    while True:
        s = ser.read()
        if s!=None:
            index = index+1
            resp.append(ord(s))
        if index>=5:
            break;
    return resp  
def resumCurrent():
    bitarray = [0x56,0x00,0x36,0x01,0x03]
    ser.write(bitarray)
    time.sleep(0.1)
    index=0
    resp=[]
    while True:
        s = ser.read()
        if s!=None:
            index = index+1
            #print(s)
            resp.append(ord(s))
        if index>=5:
            break;
    return resp  
def stopCurrent():
    bitarray = [0x56,0x00,0x36,0x01,0x00]
    ser.write(bitarray)
    time.sleep(0.1)
    index=0
    resp=[]
    while True:
        s = ser.read()
        if s!=None:
            index = index+1
            #print(s)
            resp.append(ord(s))
        if index>=5:
            break;
    return resp

def getCurrentLength():
    bitarray = [0x56,0x00,0x34,0x01,0x00]
    ser.write(bitarray)
    time.sleep(0.1)
    index=0
    resp=[]
    while True:
        s = ser.read()
        if s!=None:
            index = index+1
            #print(s)
            resp.append(ord(s))
        if index>=9:
            break;
    return resp
def getCurrentImage(hBit,lBit,dataSize):
    bitarray = [0x56,0x00,0x32,0x0C,0x00,0x0A,0x00,0x00,0x00,0x00,0x00,0x00,chr(hBit),chr(lBit),0x10,0x00]
    ser.write(bitarray)
    time.sleep(0.1)
    index=0
    resp=[]
    f=io.BytesIO()
    while True:
        s = ser.read()
        if s!=None:
            index = index+1
            #print(s)
            resp.append(ord(s))
            #f.write(s)
        if index>=dataSize:
            break;
    return resp
def reset():
    bitarray = [0x56,0x00,0x26,0x00]
    ser.write(bitarray)
    time.sleep(2)
    index=0
    resp=[]

    len = ser.inWaiting()
    s = ser.read(len)
    resp.append(s)

    return resp
def upload(device=27390392):
    url='http://api.heclouds.com/bindata'
    headers={"api-key":"*******","Content-Type":"image/jpg"}
    queryString = {"device_id":str(device),"datastream_id":"picture"}
    with open('/home/pi/Camera/image.jpg','rb') as f:
    base64_data = base64.b64encode(f.read())
        r = requests.post(url,params=queryString,headers=headers,data=base64_data)
        print(r.text)
        return f
    
if __name__ == '__main__':
    try:
        main()
    except KeyboardInterrupt:
        if ser != None:
            ser.close()
    except Exception:
        print(traceback.print_exc())

微信小程序代码如下：

wxml

    <view class="weui-flex justify">
      <button bindtap="receivePic" class="weui_btn mini_btn" style="justify-content: center;" stype="plain-default" size="mini">刷图</button>
    </view>
    <view style="height:20px;" >
    </view>
    <view style="weui-flex justify;width:100%" >
      <image src='{{userImageBase64}}'  mode="widthFix" style="width:100%;background-color: #66ffff;"/>
    </view>

js

const util = require('../../utils/util.js')

Page({
  data: {
    device: {},
    userImageBase64:{},
  },

  onLoad: function (options) {
    var _this = this;
    console.log(options.device_id);
    //查询该设备的详细信息
    wx.request({
      url: 'https://api.heclouds.com/devices/' + options.device_id, //仅为示例，并非真实的接口地址
      header: {
        'content-type': 'application/json', // 默认值
        'api-key': '**'
      },
      success: function (res) {
        console.log(res.data),
          //执行this.setData方法，就会渲染视图数据
          _this.setData({
            device: res.data.data
          }
          ),
          //修改标题栏
          wx.setNavigationBarTitle({ title: _this.data.device.title })
      }
    });
    
  receivePic:function(){
    var _this = this;
    wx.request({
      url: 'https://api.heclouds.com/devices/' + this.data.device.id + '/datapoints',
      header: {
        'content-type': 'application/json', // 默认值
        'api-key': '**'
      },
      success: function (res) {
        var __this = _this;
        console.log("PIC")
        var index = res.data.data.datastreams[1].datapoints[0].value.index;
        console.log(res);
        console.log(index)
        wx.request({
          url: 'https://api.heclouds.com/bindata/'+index,
          header: {
            'content-type': 'image/jpg', // 默认值
            'api-key': '**'
          },
          success: function (res) {
            console.log("PIC")
            var image = res.data; 
            //var a = image.split('');
            console.log(image);
            __this.setData({ userImageBase64: "data:image/png;base64," + image });
           
          }
        });

      }
    });
  },
  
})