I have an external device that we manufacture that basically monitors 4 voltages, converts them to a 16 bit digital number then streams this info back to a PC every 100mS or so, using a serial over USB style chip. Basically a data logging system.
We would now like to collect this information on an iPhone and I am wondering what is the best way to get the data into the iPhone?
I am assuming there is no way we can physically connect directly to the iPhone dock connector as the protocol to do this is not available to iOS developers?
Obviously we could do it over a WiFi network but there will not always be one and we want to keep the external hardware fairly simple, i.e. no need for a computer or Wireless router etc.
If we add Bluetooth connectivity to our hardware would this work? I read that only 'Made for iPod' type Bluetooth devices will connect, in which case how can we achieve 'made for iPod' status? It would be relatively easy to add the necessary Bluetooth chips to get the system up and running.
In an ideal world we would like to do this without having to use a 3rd party interface.
I have been thinking about trying to digitise data as an audio signal – like a modem, and send it into the line input jack, but I don’t think it will be fast enough – this would be new territory for me.
Anyway all suggestions gratefully received!
Thanks!
In GameKit I'm able to set up peer-to-peer connections. I'm wondering whether in iOS 6 I'll be able to achieve something similar with bluetooth low energy, i.e. having a Peripheral Manager advertising and a Central Manager scanning for peers at the same time.
Unfortunately there is no connection between GKSessions and Bluetooth LE, i.e GameKit doesn't look for updates in BLE status. This could have been a good thing to implement though, let's hope Apple gets their eyes open for it.
I want to develop an iOS app that uses an external hardware plug-in, kind of like Square https://squareup.com. However I was unable to find any references in Apple's documentation. Can someone point me to the right direction?
If you want to use the iPod connector to connect to your hardware, the only option is the External Accessory framework. Be advised that you must be a registered accessory developer (more expensive than the standard developer license).
I believe Square uses the audio input (others may correct me), an ingenious hack that doesn't require use of the iPod connector. If your hardware can operate over (analog) audio in/out, that might be an option to consider.
This book might help you: Building iPhone OS Accessories: Use the iPhone Accessories API to Control and Monitor Devices
In order to develop hardware accessories, you must be a member of Apple's MFi program. Despite what the user above stated, it doesn't cost anything. But it does require a lot more work than becoming an app developer.
Accessories don't necessarily need to go through the MFi process if they are NOT over 30pin connector OR bluetooth (ie, the Square connecter goes through the headphone port, or any WiFi accessories).
I have an external device (some kind of sensor) that can do a measurement. This sensor can be connected to a PC via Bluetooth or USB cable, and it also comes with it's own software.
I want to develop an App for iPhone that will analyze the data that this sensor is measuring (for example creating a graph, calculating some equations etc.).
How can I make my iPhone to "recognize" this sensor, so the app will get the data that has been measured from the sensor?
Is there any manual which explains how to code this? Our preferred way of transferring the data is via Bluetooth, so there will be no need of using cables.
Thanks a lot!
You can't use Bluetooth to transfer data unless the device is custom designed in compliance with Apple's MFi program. Only those specially manufactured devices can be recognized by an iOS app.
You can use wifi for high bandwidth data, and perhaps audio for encoding low bandwidth data.
Not sure what kind of sensor you have but PASCO scientific has a Made For iPhone Bluetooth device called AirLink2 that works with their sensors. I don't think that could easily co-opt the device for your purposes ... but it might be possible. I mention this because there's an off chance that this would useful information. I am not trying to peddle hardware here ;-)
Does anyone know what kind of range can you get from the iPhone
bluetooth? Also, would the connection be strictly one to one? I know you
can choose from a number of peers to connect to but once the connection
is established, it seems you can only transfer data between one peer? So
basically, is it possible to create some kind of "multiplayer" experience?
Just answering the range part of your question...
The 10 meter figure for class 2 devices (of which the iPhone is an example) is very much a guideline.
The range of a Bluetooth device is limited by many real world factors. The 2.4 GHz radio frequency used by Bluetooth is strongly absorbed by water. For example, consider an iPhone connected to a Bluetooth mono headset. If the headset is in one ear and the iPhone is in your trouser pocket on the opposite side of your body, then there's a lot of water between the two devices. This will often cause a significant amount of packet loss in practice (you can hear this in the audio being carried). So, in this case, the range is about one meter.
At the opposite extreme, two class 2 devices separated by nothing more than clear air can get ranges of hundreds of meters.
Other factors that influence things are:
Interference - Lots of things use 2.4 GHz. WiFi, for example can cause problems.
Antenna design - Space and cost constraints often mean that the antenna design is sub-optimal. I don't know how good the iPhone is in this respect.
Walls - Generally walls attenuate Bluetooth signals. However, sometimes they are useful reflectors.
Quality of hardware - Some chips work better than others. Even different firmware revisions of the same chip may perform differently. Different versions of the iPhone probably have (or will have) different chips in them.
Protocol - It is possible to work around poor signal quality with error correction and retransmission. Even if the iPhone SDK forces you to use a particular protocol, careful design of your application can make a difference.
So, in summary, you should probably do some real world tests.
The connection is one-to-one, but you can create an adhoc network with one of the phones acting as the master/coordinator. The other phones would route all their communication through the master/coordinator.
One device can theoretically connect to 7 devices. according to the master-slave role, the device can multiplex between each of them giving the user an impression that you are connected to all of them simultaneously. Bluetooth specification does not stop you from doing that.This is theory.
Now for the iphone, whether it can connect to to more than one device can only be answered by apple or someone who knows the iphone bluetooth API. But I am pretty sure the bluetooth chip inside iphone should be able to connect to more than one device.
Range is essentially going to be good enough for a normal sized room to be covered. It can be longer or shorter depending on environmental circumstances, but remember that bluetooth was created to implement short range connections.
A bluetooth device can be part of a piconet of eight devices, one master and up to seven slaves. The slaves cannot communicate with each other, they must talk through the master, think of a star topology with the master in the center. The iPhone SDK has a GameKit framework that can be used to create the network for multiplayer games. Go to developer.apple.com at look at the GKTank and GKRocket sample code to see how it's used. These games only support two players, but the GameKit framework supports more. Look at the app store and you will see games that have four or more players.
Hope this helps to get started.
Apple iPhone 3G has a Class 2 bluetooth module. Class 2 Bluetooth devices have a communication range of 10 meters.
At a given instance a device can connect to just one device because it follows a master/slave communication model. But still we can perform a multiplexing. So we can virtually connect to more than 1 device and by rapidly changing the connected device.
I found a good article here. It explains bluetooth very well.
According to the my knowledge, multicasting is not impossible with bluetooth. So gaining a multiplayer experience is NOT impossible.
The bluetooth in the iPhone is Class-2, with a 10-meter range, approximately.
Unfortunately I can't answer the other parts of your question.
One device can be connected up to 8 others. It all depends on the iPhone bluetooth API (which I don't know anything about), but with Bluetooth itself you could then send data to multiple devices.
I tether my iPhone to my laptop over bluetooth every day, and I seem to remember having done that at the same time as using a bluetooth headset. YMMV.
It’s the latest incarnation of Bluetooth, the wireless device-to-device technology that allows your phone to talk to headsets, car stereos, keyboards and other devices directly, without the need for a router or shared wireless network.