I am trying to detect iBeacons with a specific UUID and Major. The didRangeBeaconsInRegion is being called but the Beacon collection it returns has 0 entries.
The below is my code (abridged a bit)
private static final String BEACON_UUID = "F8AD3E82-0D91-4D9B-B5C7-7324744B2026";
private static final int BEACON_MAJOR = 36582;
#Override
public void onIBeaconServiceConnect() {
iBeaconManager.setRangeNotifier(new RangeNotifier() {
#Override
public void didRangeBeaconsInRegion(Collection<IBeacon> iBeacons, Region region) {
if (iBeacons.size() > 0) {
IBeacon thisBeacon = iBeacons.iterator().next();
}
}
});
try {
iBeaconManager.startRangingBeaconsInRegion(new Region("myUniqueID", BEACON_UUID, BEACON_MAJOR ,null));
} catch (RemoteException e) {
e.printStackTrace();
}
}
I am assuming I am doing my binding correctly as the didRangeBeaconsInRegion(..) is being called successfully.
I have used RadiusNetwork's own application to detected the beacons and that works fine and I can see them all so it is not seem to be an issue with Bluetooth on my device
A couple of tips:
Double check that your BEACON_UUID and BEACON_MAJOR are correct for the beacon that is transmitting. For testing, try setting both of these to null temporarily until you get it working, then you can set them back to the values you have.
It is normal for the iBeacons.size() to be zero sometimes if a beacon did not happen to be detected in a given cycle. But it should not always be of size zero. I'm not sure how you are testing, but try adding a Log.d(TAG, "Number of beacons detected: "+iBeacons.size()); and let it run to see if you ever get a non-zero number.
I suggest to check the uuid , major and minor values of your beacons and make them match with the region u want.
didRangeBeaconsInRegion should return an array af beacons.
You can use the "beecon" app to update easily the values.
Hope this can help you.
Regards.
Related
I am trying to get the drone absolute altitude value (ASL) in real time (before taking off)
I have 2 drones, Mavic 2 enterprise advanced & M300.
When using the below code in mavic2, I was able to obtain the ASL, however the same code returns NULL value when using with M300:
Object heightAboveSeaLevel = KeyManager.getInstance().getValue(FlightControllerKey.create(FlightControllerKey.ABSOLUTE_GPS_ALTITUDE));
Also tried with no luck the below:
DJIKey GPSKey = FlightControllerKey.create(FlightControllerKey.ABSOLUTE_GPS_ALTITUDE);
DJISDKManager.getInstance().getKeyManager().getValue(GPSKey, new GetCallback() {
#Override public void onSuccess(#NonNull Object value) {
}
#Override public void onFailure(#NonNull DJIError error) {
}
});
On a side note, when using the M300, the ASL value is shown in the DJI Pilot app.
Anyone has accomplish the above or has any ideas to what I should use?
This is from DJI:
This KEY does not currently support the M300. Do you know how to use MSDK V5, which provides the KEY for obtaining real-time altitude: KeyRTKAbsoluteAltitude?
MSDK V5：https://developer.dji.com/doc/mobile-sdk-tutorial/cn/
I've an application in Windows forms that connects to 16 serialports. The structure I used for each one is:
private void Serial_CodeNip_15_DataReceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
{
string S = Serial_CodeNip_15.ReadExisting();
myProcess(S);
}
public delegate void del_myProcess(string stringa);
private void myProcess(string stringa)
{
if (this.InvokeRequired)
{
del_myProcess tmp = new del_myProcess(myProcess);
try
{
this.Invoke(tmp, stringa);
}
catch (Exception)
{
}
}
else
{
// my code here
}
}
Receiving data from barcode readers, works fine until more Readers (up 6 or 7) start reading at the same time. In this cases my application tends to hang and all readers denotes a difficult to catch data from serial input buffers. Is this the correct way to read async data from serialports or there’s another simple way to do that. I noticed that working with few serialports there’s no problem.
Thank you in advance for helping
I have made my iphone 4s an iBeacon and able to detect this using Locate Beacon app from my Glaxy S4, 5.01, I have also detected this using beacon reference library by modifying its layout found from this question. Its showing the detect beacon in device logs from the library files as below,
onScanResult() - ScanResult{mDevice=6C:64:80:68:86:59, mScanRecord=ScanRecord [mAdvertiseFlags=26, mServiceUuids=null, mManufacturerSpecificData={76=[2, 21, -96, -54, 104, -88, 101, -76, 75, 30, -66, -91, 73, -91, -114, -5, -124, 29, 0, 0, 0, 0, -59]}, mServiceData={}, mTxPowerLevel=-2147483648, mDeviceName=null], mRssi=-46, mTimestampNanos=162979288294680}
i am getting device name always null, and also unable to get the uuid, and i can't get that in my application, can any one please help how can i get beacon info in my application ?
Also How can i uniquely identify a beacon?
Here's what i have done so far, downloaded a ALT beacon library, then ALT beacon library reference, added library dependency, and written the following code in Ranging Activity class,
modified the onCreate method as
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_ranging);
beaconManager = BeaconManager.getInstanceForApplication(this);
beaconManager.getBeaconParsers().add(new BeaconParser().
setBeaconLayout("m:0-3=0215,i:4-19,i:20-21,i:22-23,p:24-24")); // iBeacons
beaconManager.bind(this);
}
and implements this by BeaconConsumer, and added his method as
#Override
public void onBeaconServiceConnect() {
// TODO Auto-generated method stub
beaconManager.setRangeNotifier(new RangeNotifier() {
#Override
public void didRangeBeaconsInRegion(Collection<Beacon> beacons, Region region) {
if (beacons.size() > 0) {
Log.i(TAG, "The first beacon I see is about "+beacons.iterator().next().getDistance()+" meters away.");
}
}
});
try {
beaconManager.startRangingBeaconsInRegion(new Region("myRangingUniqueId", null, null, null));
} catch (RemoteException e) { e.printStackTrace(); }
}
if i run the code without,
beaconManager.getBeaconParsers().add(new BeaconParser().
setBeaconLayout("m:0-3=0215,i:4-19,i:20-21,i:22-23,p:24-24")); // iBeacons
then it works fine when add this statement get exception as mentioned before.
Finally i am able to identify my problem, my beacon parser was wrong
beaconManager.getBeaconParsers().add(new BeaconParser().setBeaconLayout("m:0-3=0215,i:4-19,i:20-21,i:22-23,p:24-24"));
i was using this while i correct results that detects an ibeacon for me are given by this parser
beaconManager.getBeaconParsers().add(new BeaconParser(). setBeaconLayout("m:0-3=4c000215,i:4-19,i:20-21,i:22-23,p:24-24"));
It sounds like you are using beacon Monitoring when you really want to be using beacon Ranging. Monitoring is used to tell you when any one of a group of beacons with shared identifier parts (or any beacon at all) is first detected. But it doesn't tell you the exact identifiers of the beacons in view.
In order to read the identifiers of beacons that are visible at a given time, you should use the Ranging APIs. These APIs give you a callback to your code once per second with a list of all visible beacons matching the Region you define.
#Override
public void didRangeBeaconsInRegion(Collection<Beacon> beacons, Region region) {
for (Beacon beacon: beacons) {
Log.i(TAG, "I see a beacon with identifiers: "+beacon.getId1()+" "+beacon.getId2()+" "+beacon.getId3());
}
}
See the Ranging Example Code on this page for more details on how to set this up.
We are trying to use Altbeacon library to satisfy the next study case:
We want to put several IBeacons in a room or corridor with a distance of no more than 3 meters between each of them, and we want to get the current closest Ibeacon based on the user phone which scans for the beacons.
We first tried to build regions with only one beacon each, wondering that a region were a closed set, meaning that when you enter in a region, you couldn’t be in other region at the same time, and when you leave a region, you enter in the next closest one and so. But that’s not the approach that the library implements.
We want to know if there’s any way in Altbeacon library to apply our approach or if some kind of patch has to be made to satisfy the study case that I present to you.
The easiest way to accomplish this goal is to range for all beacons using a single region, and start ranging:
#Override
public void onBeaconServiceConnect() {
try {
// Set up a region that matches all of your beacons. You may want to replace the first
// null with a UUID that all your beacons share.
Region allBeaconsRegion = new Region("all beacons", null, null, null);
beaconManager.startRangingBeaconsInRegion(mAllBeaconsRegion);
beaconManager.setRangeNotifier(this);
} catch (RemoteException e) {
Log.e(TAG, "Cannot connect to beacon service");
}
}
Note, if you are using a custom Application class with the RegionBootstrap, you can put the above code above inside the didEnterRegion method instead of inside the onBeaconServiceConnect method.
Once you start ranging, you will get a callback once per second with a list of all visible beacons. You can add code to determine which one is closest:
#Override
public void didRangeBeaconsInRegion(Collection<Beacon> beacons, Region arg1) {
Beacon closestBeacon = null;
for (Beacon beacon : beacons) {
if (closestBeacon == null) {
closestBeacon = beacon;
}
else {
if (closestBeacon.getDistance() > beacon.getDistance()) {
closestBeacon = beacon;
}
}
}
// Do Something with closestBeacon here
}
Keep in mind that the closest beacon may change back and forth due to radio noise, so you probably need to add extra logic to protect against the closest beacon flipping back and forth too often.
I'm using the code from the official site, and I am consistently seeing the same behavior on multiple test devices - instead of getting the current location of the device, it gets the previous location (up to 30 miles away, where I was an hour ago).
private void setupMaps()
{
watcher = new GeoCoordinateWatcher(GeoPositionAccuracy.High);
watcher.MovementThreshold = 10.0f;
watcher.StatusChanged += new EventHandler<GeoPositionStatusChangedEventArgs>(watcher_statusChanged);
watcher.PositionChanged += new EventHandler<GeoPositionChangedEventArgs<GeoCoordinate>>(watcher_PositionChanged);
new Thread(startLocServInBackground).Start();
}
void startLocServInBackground()
{
watcher.TryStart(true, TimeSpan.FromSeconds(60));
}
void watcher_statusChanged(object sender, GeoPositionStatusChangedEventArgs e)
{
switch (e.Status)
{
case GeoPositionStatus.Disabled:
// The Location Service is disabled or unsupported.
// Check to see if the user has disabled the location service.
if (watcher.Permission == GeoPositionPermission.Denied)
{
// the user has disabled LocServ on their device.
showMessage("Location is required but it is disabled. Turn it on in Settings");
}
else
{
showMessage("Location is not functioning on this phone. Sorry, Crux cannot run");
}
break;
case GeoPositionStatus.Initializing:
// The location service is initializing.
LoadingInfo.Text = "finding location";
break;
case GeoPositionStatus.NoData:
// The Location Service is working, but it cannot get location data
// due to poor signal fidelity (most likely)
// this fired intermittently when data was coming back :/
//MessageBox.Show("Location data is not available.");
break;
case GeoPositionStatus.Ready:
// The location service is working and is receiving location data.
//statusTextBlock.Text = "Location data is available.";
LoadingInfo.Text = "Location found";
// THIS FIRES AFTER POSITION CHANGED HAS STOPPED FIRING
break;
}
}
private void initPostPanel()
{
PostPanel.Visibility = Visibility.Visible;
}
void watcher_PositionChanged(object sender, GeoPositionChangedEventArgs<GeoCoordinate> e)
{
// update the textblock readouts.
latitude = e.Position.Location.Latitude.ToString("0.0000000000");
longitude = e.Position.Location.Longitude.ToString("0.0000000000");
// THIS FIRES TWICE, BEFORE STATUS IS FIRED AS READY. THEN THIS DOESN'T CALL AGAIN
}
What I would expect to have happen is to get a continuous series of calls to PositionChanged after StatusChanged is called with a Status of Ready. If the calls continued after Ready, I expect I would eventually get the correct coordinates - but it never calls after that point.
This does not occur with the emulator, only on the actual device (making this extremely difficult to test - since it actually involves driving between each test!)
I am running the source code from the tutorial as well, and it does roughly the same.
Can anyone tell me more about the expected behavior here and how I get what I need - which is simply a set of coordinates for the device at the current location when the app is being used.
I had the same problem myself - there are 2 parts to this.
Turns out the GeoCoordinateWatcher returns the last known good position - which is almost always out of date. What I do is something like this:
Check that the status is GeoPositionStatus.Ready and then ensure the datetime of the position is recent (within the last 5 mins). You can then go further and check that e.Position.Location.HorizontalAccuracy <= 350 (so under 350m) - but doing this with the datetime check as well can cause the phone to take a long time to get a position the lower you set the accuracy, so it may be best to get an initial position with the date check, and then continue to try get a better position with the Accuracy check. I also start the watcher as soon as the app starts to get faster results.
The other issue is MovementThreshold. If you do as I said above, it might still take a while before you get an accurate position, and you will likely experience the intermittent problem you mentioned where it does not fire the 2nd time (it does eventually, depending how long you wait - this can be minutes). The best thing I have found is to start the GeoCoordinateWatcher with the threshold set to 0. Once you have got an accurate position, stop the watcher, set the threshold to the actual one you want (eg 10), and then start it again. If you set this without stopping first, it will not use the new value.
<!-- language: c# -->
GeoPositionStatus = CurrentGeoDeviceStatus;
static void geoCoordWatcher_StatusChanged(object sender, GeoPositionStatusChangedEventArgs e)
{
CurrentGeoDeviceStatus = e.Status;
}
void watcher_PositionChanged(object sender, GeoPositionChangedEventArgs<GeoCoordinate> e)
{
if (gpsReady && e.Position.Timestamp.DateTime.AddMinutes(5) > DateTime.Now)
{
latitude = e.Position.Location.Latitude.ToString("0.0000000000");
longitude = e.Position.Location.Longitude.ToString("0.0000000000");
locReady = true;
}
}
It looks like the fix was to block it from using the first value and getting it from the second event instead:
bool gpsReady = false;
void watcher_PositionChanged(object sender, GeoPositionChangedEventArgs<GeoCoordinate> e)
{
if (gpsReady)
{
latitude = e.Position.Location.Latitude.ToString("0.0000000000");
longitude = e.Position.Location.Longitude.ToString("0.0000000000");
locReady = true;
}
gpsReady = true;
}
I'm still baffled about why I don't get more events or why it fires an incorrect value first, but the above code seems to be working.
One note, for anyone else trying this, is that you might think getting the value in the StatusChanged event would work, like so:
case GeoPositionStatus.Ready:
latitude = watcher.Position.Location.Latitude.ToString("0.0000000000");
longitude = watcher.Position.Location.Longitude.ToString("0.0000000000");
break;
I don't know why, but the above code seemed to work perfectly when I was running attached to the debugger and then frequently hung (that is, the event never fired and my UI seemed to hang) in practical use. I never managed to reproduced the issue while attached to the debugger.
UPDATE: It looks like this isn't working all of the time. In some cases it doesn't fire the second time and so my code never completes running. If anyone can provide more information around this that gets me closer to simply having the actual current location of the device without fail, I will definitely mark your answer as the answer. Thanks!