I'm working on a mobile game app that receives the moves from an external Bluetooth(BLE) sensor.
I wish to show the game on the TV in low latency, so the users make the moves with the sensors and look on the TV.
Options I've thought on:
Chromecast Remote Display.
Build Android TV app of the game display only and use Nearby Connections API to send the game screen data from the App to the TV.
Build Full Android TV game app that connects to BLE sensor directly.
Which option do you think will work in the lowest latency?
As Nearby Connections API also works on Wifi, does it have better connectivity and more TV models support it, than direct TV<->Bluetooth connection?
also, open to other ideas (-;
Nearby Connections is a great way to go. Just keep in mind that Nearby Connections will decide under the hood the way it will connect devices (can be bluetooth, BLE, wifi hotspots), so no guarantees regarding Wifi. Also, it is Android-only solution.
Related
I'm developing a system that identify nearby mobile devices using ESP32 for sniffing bluetooth packets.
Multiple articles indicate that it is possible to track Android phones using bluetooth, even if it is disabled:
https://qz.com/1169760/phone-data/
https://www.vozpopuli.com/memesis/balizas-google-bluetooth-ubicacion-Privacidad_0_1107489510.html
I have looked for more information on how to do it but I have not found anything.
Is only Google able to do that or anyone can do it?
Thanks.
No.
If these devices are not transmitting bluetooth packets, then it is not possible for nearby devices to listen to that traffic and identify them. What Google is doing is to require phones running Android to passively monitor for bluetooth traffic and relay this back to their servers. Phones with Google Maps installed passively relay location in the same way so that traffic maps are ~accurate in realtime.
In other words, disabling bluetooth prevents pairing and sending bluetooth traffic, but not receiving it.
If you're asking about programmatically disabling bluetooth with this caveat, take a look at this Stack Overflow question
I am developing an p2p application in android for an educational project in which I want to form groups android phones of students nearby and exchange sensor data in a university campus.
Now there are some considerations :
Devices will automatically discover each other and upon discovering connect and exchange data.
The process runs for a long time maybe 4-8 hours per day. (process of periodically sensing data and exchanging )
Now the p2p groups can be formed using either Bluetooth or WiFi (Not WiFi Direct, simple UDP packets over WiFi considering phones are connected on campus WiFi).
What are pros and cons of using Bluetooth and WiFi in this scenario in terms of reliability, power usage of phones, scalability and any other you can suggest.
Among other answers and input, I would added this answer.
First of all, before we chose WiFi or Bluetooth we need to find out the difference between those two technologies.
I have made comparison chart that covers some of the important information you might need regarding your project.
Note: There are different versions of Bluetooth's and WiFi, this chart is to represent the the general picture of Standard Bluetooth,
Bluetooth v4 and WiFi. It is always suggested to refer to manufacture
specification of each technology.
From the chart we can conclude that Bluetooth has lower power consumption vs WiFi, but at the other hand WiFi has more bandwidth than Bluetooth.
Range in general is just approximation, a lot of things affecting range like human body, obstacles, location (inside or outside), if inside; structure type and materials used inside the building, noise from other sources and devices etc.
(*) Regarding scalability, I have tested WiFi and Bluetooth v4, both system with up to 8 devices, where one of those is host (group owner, server) device and 7 others are guest (clients). see the figure below.
What regards reliability, with Bluetooth v4 I have had some time connectivity problems, but when it works than every-thing is fine.
Note: Bluetooth v4 is not back compatible with older versions of Bluetooth, so if your host is Bluetooth v4 than all other clients
should have Bluetooth v4 or vice versa.
So I will not say which one is best, but if you need longer battery life and light data communication than Bluetooth is the way. Regardless if it is Bluetooth OR WiFi you might need to start with Bluetooth to and test it, if you are happy with it than keep it, otherwise switch to WiFi.
In case you want to build your own code, the code example I followed and used previously for another university research project. It is based on 8 phones (host and client) as seen in the figure above, we collected sensor information and send it to host phone using Bluetooth 4 connection. The source code we used for that can be found here. The same project has WiFi and other type of connections.
Android official google documentation has some information and code example regarding WiFi peer to peer connection, you can follow with example of the code as well.
Regarding collecting your sensor data and sending those to one device. You could added a method that starts collecting sensor or what ever data, and after connection is established successfully than start sending it over to the other device.
As others suggest https://developers.google.com/nearby is also a way to go.
As you can rely on campus Wifi, I would definitely go with the implementation of Google Nearby APIs in my App as it was designed for such use cases...
The way it works answers your question : it makes all the heavy stuff for you, including choice between wifi or Bluetooth for better performance...
Google Nearby is definitely a good choice. You don't have to tackle all the problems when working with WiFi or Bluetooth directly. But Google Nearby only works when both devices are online and have their screens on. For a more critical review of Nearby have a look at http://blog.p2pkit.io/how-google-nearby-really-works-and-what-else-it-does
If you can not accept these limitations, you should look into other frameworks like http://www.p2pkit.io.
Disclaimer: I work for Uepaa, developing p2pkit for Android and iOS.
So I am developing an APP and I need to connect multiple android and multiple Iphone to send text data without any internet connection or service provider data network.
So one of the phone will have to act as a server to relay information between them. But the app will have to decide which phone will be the server and if a phone that is the server leaves the conversation then another phone will pickup as the server this will all be done with some smart programming but before I get there.
I know Android WiFi direct can do a one to many connection setup which makes it easy to connect android phone and accomplish the task between android phone only. But the problems comes when I need to connect Iphone with the android phones. Since the Iphone must be able to act as a server as well.
I would like to know a few things:
Can I connect Android and Iphone via WiFi Direct?
Can I connect Android and Iphone using Multipeer connectivity feature on Iphone?
Is there anyway to create a soft access point using Iphone? I know android can do this via WiFi direct feature.
If non of these can work can you suggest something.
From the discussion here it doesn't look possible
I wonder though if both OS allow enough control over the WiFi transceiver if you couldn't just write an app that could what you are asking and just bypassing the built in software architecture all together. I would think Bluetooth would be too weak except in extremely dense device saturation environments, but just for proof of concept that could be another route to take. My guess though is that you just wouldn't get that level of control over any of the radios inside a phone through the current OS.
I made a google glass app which receives some data (wireless) from a laptop
and use the data to visualize something. The network connection is simple
UDP or TCP, but I noticed that google glass often miss some data and stop
visualization for a few or several second and continue.
So I'm wondering if Google Glass's wireless network connection is stable
and reliable. Did anyone experience similar or other network problem
with own apps (glassware)?
Thanks!
Not really. You cannot expect it to perform as your laptop or phone because instead of full-circuit card that supports 802.11 b/g/n with several antennas, Glass has only one wireless module on its board. That is from a Taiwanese company with module number WM-BN-BM-04 .
You can see the details about that module here or you can even buy it from Alibaba for $10 ;) . Thus in your case, you should minimize your data or use/implement an ACKing protocol. But a bigger problem about Glass Wifi is that it only supports WEP -hackable by high school students- and WPA/WPA2. No enterprise. You can have a WIFI connection at home but unfortunately not at university, work etc. So with this in mind, you should probably design only at-home applications with WIFI.
This question follows on from Unity3D -- Send message to other mobile phones in the same vicinity
However, I made mistake of restricting to Unity3D.
So I would like to re-ask the question without that constraint.
Let us say we have 20 mobile phone users in a cave (so no Wi-Fi networks / isGPS)
One user hits a button, and every other user's screen flashes, (within a few milliseconds)
How to accomplish this?
What if everyone is using an iPhone?
What if there is a mix of iPhone and android users?
Finally, is there any solution that would cover a wider range of phones?
You should have some network so that mobiles can share some data. Bluetooth can have maximum of 10 m distance coverage (depends upon devices though). Since, all mobile are running same app they should be linked to a network and communicate. Please Check:
http://developer.android.com/samples/BluetoothLeGatt/index.html
You can create one device as server and communicate among other devices.
https://github.com/polyclef/BluetoothChatMulti
If you have installed the app on all of the devices then in all probability yes, if the device supports push (pretty much any smartphone) then you can use the push service to synchronize the devices based on geofencing (ie, 10m from my location), there are some other discovery routes you could try to (without using the B word) pinging other devices
the app would need to be able to provide some sort of server service if it was to create its own private network based on the IP addresses of the devices it found nearby, as those devices would have to connect to that phone acting as a server. the network interface shouldn't be important, but connecting the satellite devices to the server should be. You could try doing it based on which device can provide data services, aka hotspot. You can easily connect devices to networks programmatically.
at that point your faced with the classic client server problem. There is going to be a huge amount of work to get devices configured, network creation, client server infrastructure if it has to be done without data, packet optimization. Very expensive and very high risk depending on how many restrictions there are.
Search for How to make a html5 group chat and then build on that example.
Possibly send commands to the chat delimited by a / character where a javascript could then execute the command.
Good Luck with your design.
Danny117