BLE packets containing telemetry data extractor

This project provide implementation capable to extract telemetry data from Beacons' additional BLE packets. The idea is to create "extractors" dedicated for particular data types like battery voltage, temperature etc.

There is dedicated extractor for voltage implemented. Additionally "entry points" to easily create extractor for other data types are provided.

How to use extractors api

There is a single entry point to extractors api: DataExtractors. It contains preconfigured extractors for all supported telemetry data types (Actually - for purpose of this example implementation - only Battery Voltage extractor is available). Usage of DataExtractors api is rather straight forward - just choose appropriate extractor and call extract method:

private final byte payload[] = new byte[]{ 18, 36, 174, 136 ... } // Here is example BLE Package payload

final short voltage = DataExtractors.voltageExtractor.extract(payload);

Batery Voltage extractor

Just like mentioned above - choose voltageExtractor from DataExtractors api and call extract - as simple as that :) Checkout tests prepared for voltageExtractor - they are available in DataExtractorsTest class Don't be hesitate and play with them :)

What about other data types?

It's pretty obvious that Battery Voltage is not the only stuff available in Beacons' additional BLE packet. This simple project present implementation for voltage extractor only. However there are also an "entry points" to make it easy to create extractor for other types. All you need to do is:

• create extractor for java type capable to hold telemetry data you'd like to deal with. There are already available extractor for Short, Integer and Float. Creation of extractor for different type is as easy as extending BaseDataExtractor` with appropriate type parameter. Here is example for double type:

public class DoubleDataExtractor extends BaseDataExtractor<Double> {
   public DoubleDataExtractor(int startByte, int startBit, int numberOfBits) {
       super(startByte, startBit, numberOfBits);
   }

   @Override
   protected Double getValueFromBytes(byte[] bytes) {
       return ByteBuffer.wrap(bytes).getDouble();
   }

   @Override
   protected Double onErrorValue() {
       return 0.0;
   }
}

• register your extractor in DataExtractors and provide configuration parameters (starting byte in Payload array, first-significant bit in first byte and the bits count)
• that's it :)