1. Hardware devices












1.1 List of project equipment












The device name
The picture
note
Buy address

NXP Pico I. MX7D development board

Android Things 1.0
Google developers Conference giveaways can be replaced with raspberry PI

DHT12Temperature and humidity sensor

I2C data communication mode
taobao

ZE08-CH2OFormaldehyde detection sensor

UART data communication mode
taobao






1.2 INTRODUCTION to the stitching of NXP I. MX7D development board









Complete I/O interface documentation













1.3 Schematic diagram of device Wiring



















2. Aliyun IoT Kit












2.1 Open aliyun IoT kit









IoT Suite official website address






2.2 Creating advanced Products















The property name
identifier
The data type
describe

The temperature
temperature
float
DHT12 sensor acquisition

humidity
humidity
float
DHT12 sensor acquisition

Formaldehyde concentration
ch2o
double
ZE08 sensor collection













2.3 Android Things device development












Copy the code

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









Copy the code

  1. Implementation ‘org. Eclipse. Paho: org. Eclipse paho. Client. Mqttv3:1.2.0’



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  1. private void readDataFromI2C() {
  4.         try {
  7.             byte[] data = new byte[5];
  8.             i2cDevice.readRegBuffer(0x00, data, data.length);
  11.             // check data
  12. if ((data[0] + data[1] + data[2] + data[3]) % 256 ! = data[4]) {
  13.                 humidity = temperature = 0;
  14.                 return;
  15.             }
  16.             // humidity data
  17.             humidity = Double.valueOf(String.valueOf(data[0]) + “.” + String.valueOf(data[1]));
  18.             Log.d(TAG, “humidity: ” + humidity);
  19.             // temperature data
  20.             if (data[3] < 128) {
  21.                 temperature = Double.valueOf(String.valueOf(data[2]) + “.” + String.valueOf(data[3]));
  22.             } else {
  23.                 temperature = Double.valueOf(“-” + String.valueOf(data[2]) + “.” + String.valueOf(data[3] – 128));
  24.             }
  27.             Log.d(TAG, “temperature: ” + temperature);
  30.         } catch (IOException e) {
  31.             Log.e(TAG, “readDataFromI2C error ” + e.getMessage(), e);
  32.         }
  35.     }



Copy the code

  1. try {
  2.                 // data buffer
  3.                 byte[] buffer = new byte[9];
  6.                 while (uartDevice.read(buffer, buffer.length) > 0) {
  9.                     if (checkSum(buffer)) {
  10.                         ppbCh2o = buffer[4] * 256 + buffer[5];
  11. Ch2o = ppbCh2o / 66.64 * 0.08;
  12.                     } else {
  13.                         ch2o = ppbCh2o = 0;
  14.                     }
  15.                     Log.d(TAG, “ch2o: ” + ch2o);
  16.                 }
  19.             } catch (IOException e) {
  20.                 Log.e(TAG, “Ze08CH2O read data error ” + e.getMessage(), e);
  21.             }



Copy the code

  1. / *
  2. The payload format
  3. {
  4.   “id”: 123243,
  5.   “params”: {
  6. “Temperature” : 25.6,
  7. “Humidity” : 60.3,
  8. “Ch2o” : 0.048
  9.   },
  10.   “method”: “thing.event.property.post”
  11. }
  12. * /
  13. MqttMessage message = new MqttMessage(payload.getBytes(“utf-8”));
  14. message.setQos(1);
  16. String pubTopic = “/sys/” + productKey + “/” + deviceName + “/thing/event/property/post”;
  18. mqttClient.publish(pubTopic, message);









2.4 Real-time data on the cloud console









Device Management -> Running Status










3. The source code









Github.com/iot-blog/al…