I am new to using the RPi and just got the A+ model which I have been using to generate different types of data from external sensors. I was wondering if it is possible to send this data it is gathering to an android device in real-time, and if so the best method? I want to be able to notify the user (through a an app made with the Ionic framework) when the data enters a particular range etc.
And also is it possible to do this whilst the user is walking around with both the devices in hand?
The short answer to the question is: Yes, you can ;-)
The longer answer is much longer, since there are many ways to do this.
The one I personally would choose as the simplest is classic Bluetooth (not LE) using the SPP profile, which basically makes the BT link a serial connection between the RPi and the phone.
On this serial link you invent you own streaming protocol suitable for the data you want to transfer.
On the RPi side you install a module such as this: https://www.sparkfun.com/products/12577
(There are many alternatives, but the RN42 module is very foolproof...)
Don't know the level of your hardware skills, you might need something more plug and play if you feel uncomfortable hooking up the 4 wires needed for 3.3V power and serial communications between the Pi and the BT Module...
On the phone side you install https://github.com/don/BluetoothSerial, which gives you an API reachable from Ionic where you can receive the BT data stream.
With that and a bit of coding on both sides you are good to go.
I've used a Raspberry Pi in combination with an Android smartphone & Lego NXT.
Communication was achieved using Bluetooth on Raspbian. I used a cheap $1 USB Bluetooth dongle. The Bluetooth stack had to be compiled for Raspi, which may not be necessary anymore. Steps can be found here: Bluetooth error: Native Library bluecove_arm not available
Bluetooth seems most logical to me.
I'm at work at the moment, hence the lightweight answer, if you'd like to discuss this further then please leave a comment and I'll be happy to provide more verbose response.
You can upload the data to any cloud services. You can use Xively/Box. Xively is specially made for real time data collection.
To connect RPi to Xively, refer this: https://xively.com/dev/tutorials/pi/
For Box, refer this: http://www.sbprojects.com/projects/raspberrypi/webdav.php
You can then use Xively API in your android app. You can see GitHub for this
Google app store already has some apps for you, if you want to use
It might look a little complex. But its really simple once you follow the above methods.
Related
Out of curiosity... has anyone ever been able to integrate AirDrop functionality into an Android app?
I really don't care about receiving any information on the Android side, but am hoping I can send information to the iOS side from Android. I'm hoping to find someone with a more in-depth understanding of how it works and if it is physically possible. Also, any direction on whether Apple has proprietary use over the protocol (or if it is just the name and branding) would be awesome!
Trying to build a cross-platform app and getting pretty close, but this would just extremely convenient if it works out :)
Currently, it is not possible as AirDrop uses Bluetooth to create a peer-to-peer Wi-Fi network between the devices. Each device creates a firewall around the connection and files are sent encrypted, which actually makes it safer than transferring via email. AirDrop will automatically detect nearby supported devices, and the devices only need to be close enough to establish a good Wi-Fi connection, making it possible to share files across several rooms.
Some Android devices use a combination of Near Field Communications (NFC) and Bluetooth to share files. But both Bluetooth and NFC are relatively slow compared Wi-Fi, which makes sharing larger files using AirDrop much faster and more convenient.
Regarding protocol, I don't think Apple has made it public and as far as I know Apple they must have patented it. Since AirDrop uses Bluetooth as well, and Android and iPhone Bluetooth are not compatible. Hence, due to all these reasons, we did not see any Android app that can send data via AirDrop.
I'm writing an android app which is to connect a special BLE device, reading data feedback from the device. First I need to write a shake-hand code "234" to the device, and it will return a code, then start to feeding data.
I've done with the iOS version, which is quite simple to implement, however the android version has so many problems. Hope you guys have any sample which can be used for me to understand how it works in whole process. Many thx.
This is documentation from Android: http://developer.android.com/guide/topics/connectivity/bluetooth-le.html
There is an example. Please use it as guide. Pretty simple example.
About your question. What Profile to you use? You should know that BLE exchange data through the Service/Characteristic/Descriptor system. So on your device should be any Profile. Or your use any of standard?
I've been reading up on how to transfer data between iOS devices over Bluetooth using GameKit. I'm not writing a game, per se, but do have a need to transfer a small amount of binary data between two devices. Between two iOS devices, this is easy enough. However, I was wondering if it is possible to transfer data between an iOS device and an Android device via the same mechanism.
Has anyone come across documentation/tutorial that would explain how to do this? Is it even technically possible? Or has Apple put in some sort of restriction that would prevent this?
The other option I discovered was Bonjour over Bluetooth. Would this be a more suitable option for this type of operation?
This question has been asked many times on this site and the definitive answer is: NO, you can't connect an Android phone to an iPhone over Bluetooth, and YES Apple has restrictions that prevent this.
Some possible alternatives:
Bonjour over WiFi, as you mentioned. However, I couldn't find a comprehensive tutorial for it.
Some internet based sync service, like Dropbox, Google Drive, Amazon S3. These usually have libraries for several platforms.
Direct TCP/IP communication over sockets. (How to write a small (socket) server in iOS)
Bluetooth Low Energy will be possible once the issues on the Android side are solved (Communicating between iOS and Android with Bluetooth LE)
Coolest alternative: use the Bump API. It has iOS and Android support and really easy to integrate. For small payloads this can be the most convenient solution.
Details on why you can't connect an arbitrary device to the iPhone. iOS allows only some bluetooth profiles to be used without the Made For iPhone (MFi) certification (HPF, A2DP, MAP...). The Serial Port Profile that you would require to implement the communication is bound to MFi membership. Membership to this program provides you to the MFi authentication module that has to be added to your hardware and takes care of authenticating the device towards the iPhone. Android phones don't have this module, so even though the physical connection may be possible to build up, the authentication step will fail. iPhone to iPhone communication is possible as both ends are able to authenticate themselves.
Maybe a bit delayed, but technologies have evolved since so there is certainly new info around which draws fresh light on the matter...
As iOS has yet to open up an API for WiFi Direct and Multipeer Connectivity is iOS only, I believe the best way to approach this is to use BLE, which is supported by both platforms (some better than others).
On iOS a device can act both as a BLE Central and BLE Peripheral at the same time, on Android the situation is more complex as not all devices support the BLE Peripheral state. Also the Android BLE stack is very unstable (to date).
If your use case is feature driven, I would suggest to look at Frameworks and Libraries that can achieve cross platform communication for you, without you needing to build it up from scratch.
For example: http://p2pkit.io or google nearby
Disclaimer: I work for Uepaa, developing p2pkit.io for Android and iOS.
You could use p2pkit, or the free solution it was based on: https://github.com/GitGarage. Doesn't work very well, and its a fixer-upper for sure, but its, well, free. Works for small amounts of data transfer right now.
I'm relaive new to this topic so my questions are more theoretical.
I try to establish a wireless connection between a Raspberry Pi and a Smartphone to view different kinds of media (Text, Picture and Video). I have some questions regarding this about if and how this works in theory.
Is it possible for the Raspberry Pi o work on a "Standby Mode" until a client device comes near/activates it?
What are the things i need to know about the Raspberry being a server and able to communicate to other devices over WiFi? What kind of software should I use for that purpose?
Is it possible to view the File structure of the Raspberry Pi without an individual app on the smartphone (i.e. web browser)?
In case of testing the concept, which tool(s) should I use to have a relative simple way of testing conections? Is there already an (open source) project existing in hat area?
Would appreciate all / any advice.
I guess it depends on what kind of technologies you are most comfortable with. You just need to have in mind that you are working with a RPI, so it's probably better not to push it and run your full stack on it. You can always use something like Node.js and run a tiny server/API on the board, to which the devices get connected. However, there are some interesting solutions out there that work as some kind of "middleware" and allow you to offload a lot of computational and even development effort to a 3rd party.
If you are not really concerned about the "owning" the setup and don't want to waste time spinning up an entire stack you can try something like Muzzley. It will also require you to run software on the RPI (despite not being a full stack on its own), but most of the communication and interface configuration is available off-the-shelf. It provides an appropriate protocol and a library of components you can just use from the get go. On the other hand, it is flexible enough to allow you to roll out your own components.
I don't believe it will help you directly with your specific issues (standby mode, nearby device detection or file system access) - which should be solved by your own application and software stack - but it will save you a lot of time on more generic stuff by allowing you focus on that issues only.
Full disclosure: I'm part of the team working on Muzzley.
I'm trying to make an app on an Android device that will control an application on an iPad or Android tablet. (I'm testing with an Samsung Galaxy S2 and an iPad 2).
The application is pretty simple for now. When one selects a colour on the Android mobile, that colour displays on the tablet device.
The question is, how to connect the two devices. Just now I've verified that I can pair the two devices using Bluetooth. Also, the Samsung has a "Kies" Wifi Direct feature (which I don't understand fully), that allows the iPad to connect to the Galaxy as a wifi hotspot.
The connections are there, but I don't know if either protocol can be used to actually get the apps to talk to each other to get the control I'm looking for.
Should I be using Bluetooth, Wifi, or something else?
And in whichever case, how?
My opinion is that you should not stick so much around the physical medium used for connectivity either is WiFi or Bluetooth. You should abstract this aspect, in both cases you will be using sockets (I'm speaking about Android), if it's Bluetooth you will be using Bluetooth Sockets, if it's WiFi: TCP sockets. You could have a intermediate layer that abstracts the type of connection and through a factory to use either Bluetooth or TCP.
Bluetooth - http://developer.android.com/guide/topics/wireless/bluetooth.html
For WiFi you should study if P2P would help.
You will need two applications:
- one on the tablet - the server which listens for commands from the client (change color, do this or this)
- second on the smartphone - the client which sends commands.
I've built a few apps that do exactly that between iPhone and iPad. But the principle is the same. I used Bonjour networking. It's just a fancy name for ZeroConfig networking between devices. It's written originally by Apple but it's open source so there should be Android support out there for it too. Really simple and easy to work with.
If you already have a working connection then you already have the first half of your answer, that said you should really consider implementing a solution that uses a variety of connection types, WIFI, Bluetooth, etc.. The question I think you are really asking is how to pass data and messages between the apps once you have the connection.
There are a lot of ways to accomplish this. You could implement your own lightweight message passing system. If you haven't done this before it is more complicated than it originally seems, especially as you would be required to implement the system for each OS you end up using.
Should I be using Bluetooth, Wifi, or something else?
It depends on what situations you want your program to work in.
Bluetooth can provide a direct connection between your devices. A potential issue with bluetooth is that it has a limited range. If you're devices need to be far away from each other, you may want to go with wifi. Otherwise, bluetooth could work great.
If both devices are connected to the internet, you can make them talk to each other through there. The advantage of this approach is that it doesn't matter how far apart your devices are as long as they're both online. A disadvantage is that you'll have to figure out how to find the tablet's ip address before you can talk to it. This is actually a HUGE disadvantage because it can be quite problematic if both of your devices are not on the same wifi. You could have the user type in the destination ip address, but you'll have problems getting it to work if the user is behind a router (which will almost always be the case). The point is, it gets hairy.
If both of your devices are on the same wifi, you can use ZeroConf AKA bonjour (like Dancreek said) to figure out what ip address you need to send info to. I've previously used a library called jmdns (easy to find with google) to implement zero configuration networking. It's good because the user doesn't have to worry about ip addresses... it's intuitive for the user.
And in whichever case, how?
Networking is a pretty big topic, so I can't expand on this question to much. Short answer is, it depends on what method you choose. Search for some tutorials and start by getting one of your devices to send something as simple as an int to the other.