My GoogleApiClient connects successfully and my @Override public void onDataPoint(DataPoint dataPoint) {…} is called exactly once and then never again. This is within a Service that's started only after Google Fit is authorized from within the UI (that's another can of worms). The Service has another GoogleApiClient that successfully runs and is called at my specified interval.

Here's what I see from logcat:

mGoogleFitApiClient connected.
mGoogleFitApiClient listener registered.
mGoogleFitApiClient detected DataPoint: still (100.0% confidence)

It's then never called again and @Override public void onConnectionSuspended(int i) {…} is never called either.

Here's the relevant code from my Service:

private void buildFitnessClient() {
    mGoogleFitApiClient = new GoogleApiClient.Builder(this)
            .useDefaultAccount()
            .addApi(Fitness.SENSORS_API)
            .addScope(new Scope(Scopes.FITNESS_ACTIVITY_READ))
            .addConnectionCallbacks(
                    new GoogleApiClient.ConnectionCallbacks() {
                        @Override
                        public void onConnected(Bundle bundle) {
                            Log.i(TAG, "mGoogleFitApiClient connected.");
                            setupPhysicalActivityListener();
                        }

                        @Override
                        public void onConnectionSuspended(int i) {
                            if (i == GoogleApiClient.ConnectionCallbacks.CAUSE_NETWORK_LOST) {
                                Log.i(TAG, "mGoogleFitApiClient connection lost. Cause: network lost.");
                            } else if (i == GoogleApiClient.ConnectionCallbacks.CAUSE_SERVICE_DISCONNECTED) {
                                Log.i(TAG, "mGoogleFitApiClient connection lost. Reason: service disconnected");
                            }
                        }
                    }
            )
            .addOnConnectionFailedListener(
                    new GoogleApiClient.OnConnectionFailedListener() {
                        @Override
                        public void onConnectionFailed(ConnectionResult result) {
                            Log.i(TAG, "mGoogleFitApiClient connection failed. Cause: " + result.toString());
                        }
                    }
            )
            .build();
}

@Override
public void onDataPoint(DataPoint dataPoint) {
    String activityName = "";
    float confidence = 0;
    for (Field field : dataPoint.getDataType().getFields()) {
        if (field.getName().equals("activity")) {
            activityName =  dataPoint.getValue(field).asActivity();
        } else if (field.getName().equals("confidence")) {
            confidence = dataPoint.getValue(field).asFloat();
        }
    }
    lastActivityName = activityName;
    lastActivityConfidence = confidence;
    Log.i(TAG, "mGoogleFitApiClient detected DataPoint: " + activityName + " (" + confidence + "% confidence)");
}

private void setupPhysicalActivityListener() {
    SensorRequest sensorRequest = new SensorRequest.Builder()
            .setDataType(DataType.TYPE_ACTIVITY_SAMPLE)
            .setSamplingRate(15, TimeUnit.SECONDS)
            .setFastestRate(5, TimeUnit.SECONDS)
            .setAccuracyMode(SensorRequest.ACCURACY_MODE_LOW)
            .build();
    Fitness.SensorsApi.add(mGoogleFitApiClient, sensorRequest, this)
            .setResultCallback(new ResultCallback<Status>() {
                @Override
                public void onResult(Status status) {
                    if (status.isSuccess()) {
                        Log.i(TAG, "mGoogleFitApiClient listener registered.");
                    } else {
                        Log.i(TAG, "mGoogleFitApiClient listener not registered.");
                    }
                }
            });
}

The request data type is

setDataType(DataType.TYPE_ACTIVITY_SAMPLE)

Try

DataType.TYPE_STEP_COUNT_DELTA or DataType.TYPE_HEART_RATE_BPM

to see if you get the same result.(only called once)

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