I would like to connect to my Xiaomi bluetooth thermometer, read it's data periodically and send it to some API endpoint over the network.
First solution that came to my mind was native mobile app development (Android OS) which would the job but requires quite some work and I am also unsure if it's possible to connect to this particular device. Another idea was to look for general purpose app designed for connecting to bluetooth device and reading it's data yet I did not find one on Google Play store.
Is there any way to share thermometer readings over the internet without spending money on arduino for instance or any other additional components? Maybe Xamarin is a way to go to speed up mobile app development for this purpose?
Related
Background
I have an idea for an app on vacation that needs to communicate to other phones with the same app. While on vacation those phones might not all have internet as roaming can be very expensive. The data is not a lot: like 500 kB max would suffice (in json).
Every phone has a bit of info that all the other phones would like to know, but if it helps the info can be stored on 1 phone (master phone from now on) and shared later to the other phones when back home over internet.
Phones
Android, iPhone and Windows Phone
We can't assume they have NFC, IR or zigbee. Just the hardware almost every phone has like bluetooth, camera, microphone etc.
My ideas
QR codes that changes, based on new info: If the first phone is scanned the second phones QR code has data from the 1st phone and itself and the 3rd phone has data from the 1st, 2nd and 3rd (itself) until it reaches that master phone that holds all data.
Data transmission trough sound that we can't hear (or we can). Con is that I don't know if something like this exists for mobile platforms and writing it is like a 3 year master thesis project.
http://nearbytes.com
https://applidium.com
https://developer.chirp.io/
Bluetooth. Can we connect like 8 devices? Would it work consistent (connecting even my headphones can be a hassle, what about 8 phones who try to connect simultaneously)
All of these ideas have big cons. Maybe I'm overlooking a better way.
I will add a bounty to the question for the best solution
An answer that explains it with a little bit of code reference (link is ok) is always better than just: "use bluetooth man"
TL;DR
The easiest (and most supported) way of getting multiple devices to connect to each other is using WiFi. Since your goal is to achieve data transfer with no internet, the most appealing solution would be to use a Peer-to-Peer network structure.
The two major smartphone OS's (Android and iOS) have API's and documentation on creating and transferring data over a Peer-to-Peer network.
Android WiFi P2P
Apple Multipeer Connectivity
These two also have a means to encrypt the data being transferred.
Windows doesn't seem to have an API to allow multiple peers connected, but their Proximity Class will work for one device at a time.
I can give a few outlines over the different options in each major OS:
Android
Android's WiFi P2P (peer-to-peer) API was created for transferring data without internet or another network.
From their documentation:
The Wi-Fi peer-to-peer (P2P) APIs allow applications to connect to nearby devices without needing to connect to a network or hotspot (Android's Wi-Fi P2P framework complies with the Wi-Fi Direct™ certification program). Wi-Fi P2P allows your application to quickly find and interact with nearby devices, at a range beyond the capabilities of Bluetooth.
Google even has Documentation and training on this API.
iOS
Apple's Multipeer Connectivity.
Very similar to Android's P2P API, they claim:
The Multipeer Connectivity framework provides support for discovering services provided by nearby iOS devices using infrastructure Wi-Fi networks, peer-to-peer Wi-Fi, and Bluetooth personal area networks and subsequently communicating with those services by sending message-based data, streaming data, and resources (such as files).
Here is a decent looking tutorial on using Multipeer Connectivity.
--EDIT--
Another iOS way of doing this, which is a bit of a mis-utilization(?) of the tool, is by using GameKit.
However, I think that to get it to work for your purposes might result in a bit of a hack, since the "players" have to be using Game Center.
Windows
The only way (apparently) to connect phones in Windows Phone, is by using Proximity, however, that only gives you the option of connecting no more than two phones together.
They state:
Proximity is a great way to create a shared app experience between two instances of your app running on two different devices.
Those are options in each of the major mobile device OS's.
App usage could be something like:
Decide which device was going to be the "master", so that other devices can connect to it. It isn't required to know this before deploying the app, but there should be a way for the user to decide whether he is going to be a client (receiving data) or the server (pushing data).
Once it was decided between the group of devices which was going to be pushing data, that device would have to be registered as the server (in the Android P2P API, you can establish a "group owner"), and then start looking for peers by initializing the service.
Then, once the devices are connected to the master device, you can start pushing data. An additional bonus is that when using Android WiFi P2P, all communication is encrypted with WPA2, and with iOS, you can enable encryption using MCEnableEncryption (however they state that is slows down data transfer rate).
Now you would just have to pick one method to go with, and make sure that all the phones ran that OS. Because these three methods of connectivity won't work together.
All of the three methods listed are done programmatically, so there should be no strange or odd things that your user will have to do. Searching for other devices, connecting, and transferring data can all be done within your app.
More help can be provided if the question is narrowed down to specific problems, but this should be enough data to get you started.
Don't try QR or sound. I think it would be very painful to transmit 500kb of data.
Bluetooth seems like a good solution but maybe, as you already said, hard to configure.
What do you think about wifi?
At least every Android and iPhone device can create a mobile wifi hotspot. By using this, you can easily setup a environment where 8 devices are in the same LAN (without using the internet by any of your devices).
Now your "master phone" runs a simple server to synchronize data (just like an internet server would do). Every of the seven clients could receive the ip adress of you master by scanning a simple QR code or sending a short message and afterwards configure itself accordingly.
Have you checked Alljoyn?
As quoted:
"Developers can write applications for interoperability regardless of transport layer, manufacturer, and without the need for Internet access"
You can create a Wifi connection between your devices. Than after connection it creates local network between your devices. Inside this network you, of course, can interact between your devices using TCP/IP connection. It works both on Android and iOS. Simply lauch your app as server on the one device
EDIT
Note, you have to connect your devices using any network. It is possible to connect the devices by initializing your device as WiFi-router. It can be both Android and iOS. If it is possible, you can connect your devices to any wifi connection.
Than, launch your app as Server-socket, the others as clients.
for Android (java) server use this link:
https://docs.oracle.com/javase/tutorial/networking/sockets/clientServer.html
try (
ServerSocket serverSocket = new ServerSocket(portNumber);
Socket clientSocket = serverSocket.accept();
PrintWriter out =
new PrintWriter(clientSocket.getOutputStream(), true);
BufferedReader in = new BufferedReader(
new InputStreamReader(clientSocket.getInputStream()));
) {
for android device client:
try (
Socket kkSocket = new Socket(hostName, portNumber);
PrintWriter out = new PrintWriter(kkSocket.getOutputStream(), true);
BufferedReader in = new BufferedReader(
new InputStreamReader(kkSocket.getInputStream()));
)
The same idea is for iOS (Objective-C):
server
https://developer.apple.com/library/ios/documentation/NetworkingInternet/Conceptual/NetworkingTopics/Articles/UsingSocketsandSocketStreams.html#//apple_ref/doc/uid/CH73-SW8
and client:
https://developer.apple.com/library/ios/documentation/NetworkingInternet/Conceptual/NetworkingTopics/Articles/UsingSocketsandSocketStreams.html#//apple_ref/doc/uid/CH73-SW4
A better way could be use Ble.
It's easiers to connect the phones because you don't need user confirmation.
Seems like you can connect up to 20 devices Maximum number of peripherals on CoreBluetooth?.
To transfer 500KB should require few minutes (may be between 2 and 5).
You can track an Android device without Internet via GPS.
Connection without The Internet:
SMS
USSD
DTMF (very slow)
How to design a tracking device on USSD is mentioned at
M2M IoT Cookbook
How to develop a device based on Wireless Wide Area Network modules
You also can use the Android phone as a data logger and store under the Micro SD Card and read the card by:
Replacing the SD card to your PC
Streaming the data local by Bluetooth
Forwarding the data at home by Wi-Fi
Or Possibly:
Your app can use SMS API to transmit the DATA or other SOURCES.
So I am trying to develop an idea that has two core apps -
The user
The "alerter"
Basically, the alerter sends out a message that is received by all the phones with the app made for the users, but within a specific radius and not all. Any old programs I can look up into? or any tips, ideas? I'm literally new to the android coding world.
Your help is highly appreciated. Thanks :)
There are numerous ways that could be done, including:
Bluetooth detection
this is not feasible until Android supports becoming a Bluetooth Low Energy transmitter
WiFi detection
the devices must be on same access point to have network connectivity with each other
Server-side
All devices update a common server with their location
Devices can then query server for (reported) nearby devices
Server can also push new devices using GCM or Push IO
You could maybe start by looking for apps that do this sort of thing already. One is the instant-messaging app WeChat, and there are also some dating apps that allow users to make contact with nearby potentials.
Also read Find nearby users of an app (iPhone and Android)
I think you should start with Google Cloud Messaging:
Google Cloud Messaging for Android (GCM) is a service that allows you
to send data from your server to your users' Android-powered device,
and also to receive messages from devices on the same connection. The
GCM service handles all aspects of queueing of messages and delivery
to the target Android application running on the target device. GCM is
completely free no matter how big your messaging needs are, and there
are no quotas.
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 have to make an application to pair an iOS and Android device (iPhone 5, iPad 3, Galaxy S3, Nexus 7 they all use Bluetooth 4.0) and then send data to each other.
Is this amount of data limited ? Can we send something like a photo or a PDF?
I've already done the pairing and sending data between 2 iOS devices using CoreBluetooth and the sample code from Apple BTLE_Transfer
Of what i understood, a Peripheral (Server) can Advertise to a Central (Client).
This central is scanning around itself, and then try to find the Server by looking for the UUID of the service advertised.
When i make a Server on Android, it is waiting for a connection (listening), i know the UUID and the mac address of my Server.
But when i scan with my iPhone (scanning for the same UUID of course), i can't find the server.
So is there a possibility for the android server to advertise like the Peripheral on iOS?
Or maybe a possibility for my iPhone client to connect using the mac address of the server?
Q: Is this amount of data limited ? Can we send something like a photo or a PDF?
Bluetooth Low Energy was not optimised for sending large amounts of data, nor is it optimised for streaming. It is more suitable for sending small chunks of data periodically (e.g. temperature readings, time, etc). Please have a look at this answer to understand how BLE transfer is different from classic Bluetooth. That being said, you can still send large amounts of data over BLE, and the amount of data is unlimited. However, this might end up being unreliable and relatively slow.
Q: So is there a possibility for the android server to advertise like the Peripheral on iOS?
Being a server/client is a completely different thing from being a peripheral/central:-
Peripheral/central dictates how the connection is made. A central device should initiate the connection. A peripheral device should advertise and wait for a connection request.
Client/Server dictates how the data is distributed. The Gatt Server holds the data. The Gatt Client can read, write or be notified (getting a continuous stream of readings) of this data. In most cases, the server is also the peripheral, but this is not mandatory.
So to answer your question, yes, the server can advertise like the peripheral on iOS. However, for Android, this feature is not yet available and will be part of the next version (Android L) release. Please see this answer for more information.
Q: Or maybe a possibility for my iPhone client to connect using the mac address of the server?
As far as I know, in coreBluetooth you would need the UUID, not the MAC Address, of a peripheral device to connect to it. You do not need to know the services being advertised from the peripheral device. Your best bet would be to scan for peripheral devices, and then connect to the one with the UUID and/or the advertising data that u know belong to your peripheral.
I hope this helps.
I'm not sure. Bluetooth LE isn't good idea to transfer large files. In one request phone you have only 18 bytes.
Nexus 7 bluetooth chip has some defect - not work correctly.
Try free application for IPhone - Light Blue.
so...
First question: yes.
Second: Yes but it's not good idea. MAc address in Iphone is alternating every 10 minutes and all turn on/off bluetooth.
In general, sending large files is best done using an internet connection (over the cloud), there are many frameworks that can cut down the overhead for you.
However, the main question is still how to discover to which device you would want to send the data.
There could be multiple ways of doing that on your own such as using BLE or even sound.
To be honest, its a lot of work so if your app is end-user driven, i would suggest using a framework that can do cross platform discovery for you such as: http://p2pkit.io or google nearby.
Disclaimer: i work for Uepaa developing p2pkit for iOS and Android
I am working on a dual application on android sdk and kinect sdk. I want to be able to have the kinect send data to a smartphone application. The smartphone application will then give notifications to the user based on the kinect data. The smartphone should be able (hopefully) to turn the kinect on/off and maybe a few other basic commands. How can I get the kinect and smartphone application communicate?
Cool concept, I'm a huge fan of the Kinect (when used on Windows; I think it's a gimmick for the Xbox).
For starters, you can't directly interface with the Kinect from a smartphone. Kinect needs a USB connection, external power, and a Windows 7 machine with a 2.6 GHz dual core processor. So now it becomes a question of connecting a server application running on the Windows 7 machine and a client application on the Android phone. There's a few ways you could do this (USB, WiFi, TCP), but all of them suffer somewhere. USB would tether you to the computer, making the smartphone app redundant (just use the computer since you're already connected to it). WiFi is probably the best choice if you intend to send serious amounts of data, but would only work in your house. TCP (or UDP) could work for some applications, but if you start trying to stream video your phone will hate you.
I'm going to assume you're not going for a data-heavy application (video streaming to phone). If you're just looking to send off notifications from the Kinect to the Android (for example, use the Kinect as a motion detector and send messages to the Android when someone enters the room), similar to a text message update, you could certainly pull off the TCP/IP solution, and probably quite easily. You'd set up a simple TCP server on the Windows 7 computer with the Kinect, and then connect to it with a TCP request (look at the Client side code). Once you've got that set up, it's easy to send messages between the Kinect and the smartphone app. For starters, just try to get a few quick messages sent over. Server says "HI THERE", Android replies "I HATE YOU WINDOWS", etc, and make sure the messages are making it to their destination (TCP pretty much guarantees they will). After you have that running, just build your apps up around it.
If you're willing to eschew the use of the official Microsoft SDK, the Point Cloud Library (built on top of OpenNI) has a framework and tutorial in place for streaming.