Add support for chipsea / OKOK 2.0 scales

android_app/app/src/main/java/com/health/openscale/core/bluetooth/BluetoothFactory.java

@@ -118,6 +118,9 @@ public static BluetoothCommunication createDeviceDriver(Context context, String
         }
         if (deviceName.equals("Hoffen BS-8107")) {
             return new BluetoothHoffenBBS8107(context);
+	}
+        if (deviceName.equals("ADV")) {
+            return new BluetoothOKOK(context);
         }
         return null;
     }

android_app/app/src/main/java/com/health/openscale/core/bluetooth/BluetoothOKOK.java

@@ -0,0 +1,98 @@
+package com.health.openscale.core.bluetooth;
+
+import android.bluetooth.le.ScanResult;
+import android.content.Context;
+import android.bluetooth.le.ScanFilter;
+import android.os.Handler;
+import android.os.Looper;
+import android.util.SparseArray;
+
+import com.health.openscale.core.datatypes.ScaleMeasurement;
+import com.welie.blessed.BluetoothCentral;
+import com.welie.blessed.BluetoothCentralCallback;
+import com.welie.blessed.BluetoothPeripheral;
+
+import org.jetbrains.annotations.NotNull;
+
+import java.util.LinkedList;
+import java.util.List;
+
+import timber.log.Timber;
+
+public class BluetoothOKOK extends BluetoothCommunication {
+    private static final int MANUFACTURER_DATA_ID = 0x20ca; // 16-bit little endian "header" 0xca 0x20
+    private static final int IDX_FINAL = 6;
+    private static final int IDX_WEIGHT_MSB = 8;
+    private static final int IDX_WEIGHT_LSB = 9;
+    private static final int IDX_IMPEDANCE_MSB = 10;
+    private static final int IDX_IMPEDANCE_LSB = 11;
+    private static final int IDX_CHECKSUM = 12;
+
+    private BluetoothCentral central;
+    private final BluetoothCentralCallback btCallback = new BluetoothCentralCallback() {
+        @Override
+        public void onDiscoveredPeripheral(@NotNull BluetoothPeripheral peripheral, @NotNull ScanResult scanResult) {
+            SparseArray<byte[]> manufacturerSpecificData = scanResult.getScanRecord().getManufacturerSpecificData();
+            byte[] data = scanResult.getScanRecord().getManufacturerSpecificData(MANUFACTURER_DATA_ID);
+            float divider = 10.0f;
+            byte checksum = 0x20; // Version field is part of the checksum, but not in array
+            if (data == null || data.length != 19)
+                return;
+            if ((data[IDX_FINAL] & 1) == 0)
+                return;
+            for (int i = 0; i < IDX_CHECKSUM; i++)
+                checksum ^= data[i];
+            if (data[IDX_CHECKSUM] != checksum) {
+                Timber.d("Checksum error, got %x, expected %x", data[12] & 0xff, checksum & 0xff);
+                return;
+            }
+            if ((data[IDX_FINAL] & 4) == 4)
+                divider = 100.0f;
+            int weight = data[IDX_WEIGHT_MSB] & 0xff;
+            weight = weight << 8 | (data[IDX_WEIGHT_LSB] & 0xff);
+            int impedance = data[IDX_IMPEDANCE_MSB] & 0xff;
+            impedance = impedance << 8 | (data[IDX_IMPEDANCE_LSB] & 0xff);
+            Timber.d("Got weight: %f and impedance %f", weight / divider, impedance / 10f);
+            ScaleMeasurement entry = new ScaleMeasurement();
+            entry.setWeight(weight / divider);
+            addScaleMeasurement(entry);
+            disconnect();
+        }
+    };
+
+    public BluetoothOKOK(Context context)
+    {
+        super(context);
+        central = new BluetoothCentral(context, btCallback, new Handler(Looper.getMainLooper()));
+    }
+
+    @Override
+    public String driverName() {
+        return "OKOK";
+    }
+
+    @Override
+    public void connect(String macAddress) {
+        Timber.d("Mac address: %s", macAddress);
+        List<ScanFilter> filters = new LinkedList<ScanFilter>();
+        ScanFilter.Builder b = new ScanFilter.Builder();
+        b.setDeviceAddress(macAddress);
+        b.setDeviceName("ADV");
+        b.setManufacturerData(MANUFACTURER_DATA_ID, null, null);
+        filters.add(b.build());
+        central.scanForPeripheralsUsingFilters(filters);
+    }
+
+    @Override
+    public void disconnect() {
+        if (central != null)
+            central.stopScan();
+        central = null;
+        super.disconnect();
+    }
+
+    @Override
+    protected boolean onNextStep(int stepNr) {
+        return false;
+    }
+}