谷歌Android things接入阿里云IoT物联网套件

谷歌Android things物联网硬件接入阿里云IoT物联网套件云端实战

1.硬件设备

1.1 项目设备列表

设备名	图片	备注	购买地址
NXP Pico i.MX7D开发板		Android things系统1.0	谷歌开发者大会赠送可以用树莓派替代
DHT12温湿度传感器		I2C数据通信方式	淘宝
ZE08-CH2O甲醛检测传感器		UART数据通信方式	淘宝

1.2 NXP i.MX7D开发板针脚介绍

NXP Pico i.MX7D 完整I/O接口文档

1.3 设备接线示意图

2.阿里云IoT物联网套件

2.1 开通阿里云IoT物联网套件

IoT物联网套件官网地址

2.2 创建高级版产品

添加产品属性定义

属性名	标识符	数据类型	描述
温度	temperature	float	DHT12传感器采集
湿度	humidity	float	DHT12传感器采集
甲醛浓度	ch2o	double	ZE08传感器采集

2.3 Android things设备端开发

a) 使用Android Studio创建Android things工程，添加网络权限
<uses-permission android:name="android.permission.INTERNET" />

b) gradle引入eclipse.paho.mqtt

implementation 'org.eclipse.paho:org.eclipse.paho.client.mqttv3:1.2.0'

c) 通过I2C读取DHT12数据

private void readDataFromI2C() {


        try {


            byte[] data = new byte[5];
            i2cDevice.readRegBuffer(0x00, data, data.length);


            // check data
            if ((data[0] + data[1] + data[2] + data[3]) % 256 != data[4]) {
                humidity = temperature = 0;
                return;
            }
            // humidity data
            humidity = Double.valueOf(String.valueOf(data[0]) + "." + String.valueOf(data[1]));
            Log.d(TAG, "humidity: " + humidity);
            // temperature data
            if (data[3] < 128) {
                temperature = Double.valueOf(String.valueOf(data[2]) + "." + String.valueOf(data[3]));
            } else {
                temperature = Double.valueOf("-" + String.valueOf(data[2]) + "." + String.valueOf(data[3] - 128));
            }


            Log.d(TAG, "temperature: " + temperature);


        } catch (IOException e) {
            Log.e(TAG, "readDataFromI2C error " + e.getMessage(), e);
        }


    }

d) 通过UART获取Ze08CH2O数据

try {
                // data buffer
                byte[] buffer = new byte[9];


                while (uartDevice.read(buffer, buffer.length) > 0) {


                    if (checkSum(buffer)) {
                        ppbCh2o = buffer[4] * 256 + buffer[5];
                        ch2o = ppbCh2o / 66.64 * 0.08;
                    } else {
                        ch2o = ppbCh2o = 0;
                    }
                    Log.d(TAG, "ch2o: " + ch2o);
                }


            } catch (IOException e) {
                Log.e(TAG, "Ze08CH2O read data error " + e.getMessage(), e);
            }

e) 创建阿里云IoT连接，上报数据

/*
payload格式
{
  "id": 123243,
  "params": {
    "temperature": 25.6,
    "humidity": 60.3,
    "ch2o": 0.048
  },
  "method": "thing.event.property.post"
}
*/
MqttMessage message = new MqttMessage(payload.getBytes("utf-8"));
message.setQos(1);

String pubTopic = "/sys/" + productKey + "/" + deviceName + "/thing/event/property/post";

mqttClient.publish(pubTopic, message);