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设备端SDK开发
因为树莓派基于Python语言，需要配置两个Python SDK： IoT设备端接入SDK和OSS文件上传SDK。
设备端SDK开发代码示例如下：
引入相关库。 import aliyunsdkiotclient.AliyunIotMqttClient as iot ##导入阿里云的设备MQTT库，如果import失败需要先pip3 install
import json
import multiprocessing
import time
import random
import oss2 ##导入阿里云的OSS库，如果import失败需要先pip3 install oss2
from picamera import PiCamera ##树莓派的摄像头，系统自带
import RPi.GPIO as GPIO ##GPIO口，接红外PIR使用
OSS Bucket访问授权 。auth = oss2.Auth('**YourAccessKeyId**','**YourAccessKeySecret**') ##OSS的授权，需要您的阿里云账号AccessKey ID和AccessKey Secret,具体查看https://usercenter.console.aliyun.com/#/manage/ak
bucket = oss2.Bucket(auth,'http://oss-******.aliyuncs.com','**YourBucketName**') ##请在OSS控制台，Bucket的概览页查看具体信息
global picURLtoIoT
camera = PiCamera()
camera.resolution = (800,600) ##拍照分辨率，越高越容易分析，但是上传速度越慢
初始化树莓派。 def init():
GPIO.setwarnings(False)
GPIO.setmode(GPIO.BOARD)
GPIO.setup(3, GPIO.IN)
pass
定义图像上传OSS Bucket。 def take_photo():
ticks = int(time.time())
fileName = 'test%s.jpg' % ticks ##在文件名加入时间戳作为简易加密手段
filePath = '/home/pi/Pictures/%s' % fileName
camera.capture(filePath)
bucket.put_object_from_file('bucket_file_name/%s', fileName) ##在这里改bucket名称
global picURLtoIoT
picURLtoIoT = 'http://**您的bucket名称**.oss-******.aliyuncs.com/bucket_file_name/%s' % fileName ##图片存储URL，需替换为您的bucket名称和bucket内文件名称
print(str(picURLtoIoT))
定义红外线感应器检测到有人时，摄像头拍照，否则休眠5秒。 def detectPeople():
if GPIO.input(3) == True:
take_photo()
else:
time.sleep(5)
options = {
'productKey':'**设备的ProductKey**',
'deviceName':'**设备的deviceName**',
'deviceSecret':'**设备的deviceSecret**',
'port':****,
'host':'iot-as-mqtt.******.aliyuncs.com' ##物联网平台域名
}
host = options['productKey'] + '.' + options['host']
def on_message(client, userdata, msg):
topic = '/' + productKey + '/' + deviceName + '/update'
print(msg.payload)
def on_connect(client, userdata, flags_dict, rc):
print("Connected with result code " + str(rc))
def on_disconnect(client, userdata, flags_dict, rc):
print("Disconnected.")
定义设备上报数据到物联网平台。 def upload_device(client):
topic = '/sys/'+options['productKey']+'/'+options['deviceName']+'/thing/event/property/post'
while True:
payload_json = {
'id': int(time.time()),
'params': {
'people':1 ##物模型里布尔值以0和1的形式上报
'picURL': picURLtoIoT,
},
'method': "thing.event.property.post"
}
print('send data to iot server: ' + str(payload_json))
client.publish(topic, payload=str(payload_json))
if __name__ == '__main__':
client = iot.getAliyunIotMqttClient(options['productKey'], options['deviceName'], options['deviceSecret'], secure_mode=3)
client.on_connect = on_connect
client.connect(host=host, port=options['port'], keepalive=60)
p = multiprocessing.Process(target=upload_device, args=(client,))
p.start()
detectPeople()
GPIO.cleanup()
client.loop_forever()
完整的示例代码，请参见本文结尾附录：设备端SDK代码示例。
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