Integrating Android Things with Alibaba Cloud IoT

3 min readNov 12, 2018

In this article, we will show you how you can connect Android Things to your Internet of Things (IoT) network easily with Alibaba Cloud IoT Platform. We will build a functional formaldehyde and temperature sensor for this project.

Hardware Devices

Project Device List

NXP i.MX7D Pins

NXP Pico i.MX7D full I/O interface document

Device Wiring Diagram

Alibaba Cloud IoT Configuration

After setting up the hardware, it’s time to configure the software on Alibaba Cloud IoT Platform.

First, navigate to the IoT console and activate Alibaba Cloud IoT. Create an advanced product and add product attribute definition:

Android Things Device Development

Create an Android Things project using Android Studio, and grant network permissions

<uses-permission android:name="android.permission.INTERNET" />

Add the “eclipse.paho.mqtt” repository to gradle

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

Read DHT12 data through I2C

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); } }

Obtain Ze08CH2O data through UART

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); }

Create an Alibaba Cloud IoT connection and report the data

/* payload format { "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);