Experts, I want to develop an app (with accompanying hardware) that turns 2 leds (Light Emitting Diodes), in different frequencies, I found this pin out for the iphone/ipad connector
link.
The questions are:
what pin should be the best to accomplish my flickering led? pin#? and and (GND off course),
what function in objective C will allow me to do this?,
I found this site for buying the connectors, do you have a better one?
I intend to have the earphones connected as well, so the sound pins are not an option,
thank you in advance!
edit>
here an example of an
external flash light for the iphone
light
so I ask you guys please the same question, what pin and what function is used to turn this light on?, I can take care of the frequencie generation and the electronics, thanks!
The ExternalAccessory.framework is the best place to start. It's covered in the External Accessory Programming Topics.
Manufacturers must build explicit
support into their accessory hardware
for communicating with iOS. As part of
this support, an accessory must
support at least one command protocol,
which is a custom scheme for sending
data back and forth between the
accessory and an attached application.
Apple does not maintain a registry of
protocols; it is up to the
manufacturer to decide which protocols
to support and whether to use custom
protocols or standard protocols
supported by other manufacturers.
It's basically all up to you to create the protocol but the ExternalAccessory.framework is where iOS meets the external device.
Original answer, which would sound snarky to an electronics engineer, removed. :-)
Related
I am looking to write application for iPhone which will be able to control radio and CD player in car. Radio and player have Bluetooth connection available.
I started this question in order to obtain all informations I need for this one one place. I have few questions, but if you find anything I didn't ask important for me to start developing this application, please, let me know.
I have read about AVRCP profile and Bluetooth device in car supports AVRCP 1.3, which is good enough for me, having in mind controls which can be performed in that protocol version.
I read a lot about people saying "Apple device can only interact with each other", "Apple device can't be connected via Bluetooth to non-Apple device", "MFi program is obligatory if you want to do that", "MFi is not needed", etc. My first question is:
1)Is it even possible to pair iPhone (4, 4S) with radio and CD player in car via Bluetooth and control radio stations and music with any iPhone version? If yes, what are the limitations for making this kind of successful Bluetooth connection?
There is also very few informations about roles in which iPhone can work. For AVRCP there are two kind of roles: controller and target role. By reading this paper: https://developer.apple.com/hardwaredrivers/BluetoothDesignGuidelines.pdf I didn't find answer to my second question:
2) Can iPhone act as a controller and issue all available commands stated in AVRCP 1.3 to target device (radio and CD player)?
I would also like to know about available frameworks for this particular problem. I know there are several of them, but if anyone recognizes the right one for my problem, I'd like to know:
3) Which framework for interacting with target device should I use?
From developer point of view, I am also interested in available APIs for interacting with connected Bluetooth device. Since I am making my own application and assigning actions to buttons, inside of methods assigned to buttons I need to perform message sending to target device. So my next question is:
4) Does anyone know how if there's a way to send commands to target device (start/stop/pause/forward/backward, etc) as part of some API provided in XCode, or each message which I attend to send via Bluetooth to target device I need to make according to protocol documentation (make entire message (header, body, command part, etc) by myself)?
AVRCP was my thought for accomplishing this application. If I am wrong, please let me know.
Bluetooth has different profiles and when message is sent from one device, as far as I understand, profile itself handles message and interprets it and delivers to target device so target device can understand it. I do not understand how a message sent from iPhone to target Bluetooth device is handled from the moment I send it from my Objective-C (or C) code. That's the main doubt I have and it is related with question 4 - do I need to make raw messages in correct format in order to send AVRCP commands to device or I can use some API which will recognize those messages as AVRCP (or any other kind) and deliver it to target device?
This last question (if I suppose there is any kind of positive answer to all previous) concerns me the most from developer point of view. So, if anyone had maybe experience with this specific problem, I would appreciate any kind of answer or advice.
I am really looking forward to your answers. I hope that constructive and useful discussion will start on this topic and that lots of useful informations will be written.
Best regards.
You can do it using CoreBluetooth if your device (CD Player) is Bluetooth 4.0 LE compliant
Most likely you shall not be able to do it even if your car CD player has BLE 4.0.
With Core Bluetooth devices act as "Central" (client) or "Peripheral" (server), the peripheral "has data" and expose services with characteristics (variables). The central (client) reads data from the peripheral or subscribe for notifications.
Your only chance is to connect to the CD player as peripheral (server) and your iPhone being the central (client). In this case the CD player must expose services that allow you to control it. To be honest I do not know how this can be done, since the central (the iPhone) will read data and receive notifications from the peripheral, not vice versa.
Reversing roles, implementing iPhone as peripheral makes sense, but there is no predefined Bluetooth LE service for remote control, so your car CD player does not know what service to expect from you. It might work using HID service (Human Interface Device), used in general for keyboards and mouse, but according to this post the HID is forbidden by Apple on iOS.
I want to control a string of LEDs directly from my iPhone. The LED controller chips talk the i2c serial protocol.
Can I do this with Apple-supported APIs on a non-jailbroken iPhone? Which frameworks do I need to use?
Yes, but you will need an external hardware to do that. iOS does not give you access directly to I2C in the docking connector.
KissBos has a OEM board to do that, with a special firmware. You can connect to their board via WiFi, using a TCP based protocol, or via a RTP-MIDI based protocol (RTP-MIDI is implemented in iOS, you don't have to deal with the protocol details, it's just a MIDI port for your application).
If you want to go through the dock connector, you will need their USB interface (it will transform the USB into RTP-MIDI, which goes in the OEM board)
I'm quite sure that you can't do that. Apple is very strict about what you are allowed to and not. I spent days trying to find a way to get access to the iphone's bluetooth layer and ended up with my head against the wall (only a limited game api is public, else you have to go with the Made For Iphone program). However, you are able to do some stuff using the usb cable, but I guess that the possibilities are limited with that too.
Intro: I have a Denon S-52 internet radio with an iPod/iPhone dock (the older 12V kind, so charging is not possible with newer devices but audio/control data is passed through). The radio has an external clickwheel-like control that worked beautifully with iPod nano/classic etc. Since the iPhone/iPod touch no longer have any clickwheel functionality, the signals from the Denon clickwheel no longer have any effect while playing (ie no seeking), but can navigate through some menus on iOS, and play/pause works. The few clickwheel apps I've tried obviously ignore the external signals.
Questions: How hard would it be for someone with no iOs programming experience (just C/C++/C#, plus an objective C tutorial from lynda.com) to develop a basic audio player app that would accept signals from the external Denon clickwheel to seek within an audio file (for my own use, at least at first)? I'm assuming this is possible because the signals are sometimes processed (as mentioned above), but I'd be happy to be proven wrong before I waste a lot of time and effort. I also assume a standard $99 iOS developer membership would be enough (since the device itself is already MFi)? Or perhaps an app that has this feature already exists?
How hard would it be for someone with no iOs programming experience (just C/C++/C#, plus an objective C tutorial from lynda.com) to develop a basic audio player app that would accept signals from the external Denon clickwheel to seek within an audio file (for my own use, at least at first)?
Nearly impossible. It's not just the challenge of figuring out how to access the dock connector and interpret the signals of interest. The real problem is that you want to use those signals to control music that's playing, and you're probably thinking of trying to control the iPod application rather than writing your own music player. Communicating between two apps is difficult at best, and probably not possible if the target app (iPod) doesn't provide a mechanism for external control. And the fact that you're new to the platform doesn't make any of this easier.
Your best hope is probably to file a bug with Apple requesting this feature and hope that they'll add it for you.
I was able to do this by jailbreaking my iOS device, which enabled me to access the serial port for iPod Access Protocol communication at /dev/tty.iap. Then I could incorporate something like the functions found in this iPhone Serial Port Tutorial (check archive.org if the link no longer works) to read the incoming signals and respond accordingly.
Update: An even better solution seems to be to write a tweak hooking into the iPodUI private framework and intercept the commands directly, and then message the Music player about what to do (see this post for more details).
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'm in the process of planning out a personal project that will be a media player and one of the things I would like to do is be able to dock my iPod touch (or any iPod or iPhone) and control it and play music off it like the speaker docs do that you can buy.
I found some information while searching around online for this but my question is can I make up a cable and use the serial protocol from any device or does Apple have this locked down so only certified/approved devices can communicate this way?
If you are looking to do this for yourself, I would recommend jailbreaking and the following resources on the web. These describe some methods of the Apple Accessory Protocol, and include some parts (at sparkfun) to execute. To get approved for the Apple method you need a corporation (or similar structure) and even legal counsel before you can get approved to even see the agreement you have to agree to in order to join.
http://nuxx.net/wiki/Apple_Accessory_Protocol
http://www.sparkfun.com/categories/101
There are even some great articles out there such as:
http://courses.cit.cornell.edu/ee476/FinalProjects/s2007/awr8_asl45/awr8_asl45/index.html
Good luck!
EDIT:
Since this is a relatively popular post, keep in mind that you can now use Bluetooth 4.0 LE for serial communication without approval from Apple (other than AppStore approval).
https://developer.apple.com/library/ios/documentation/NetworkingInternetWeb/Conceptual/CoreBluetooth_concepts/AboutCoreBluetooth/Introduction.html
Only devices in the Made for iPod program which use Apple's proprietary authentication chip can communicate with the External Accessory framework on the iPhone or iPod touch. Such devices must also expose a protocol that iPhone applications can use.
It is a reasonably involved process to be approved as a Made for iPod vendor of products (similar to the App Store approval process, but for hardware), but it has become a lot easier than it used to be. With iPhone OS 3.0, Apple has opened up the program to many more third parties than just the usual large accessory providers.
In your case, I'd actually wait and use another vendor's iPhone-controllable stereo. Manufacturers are just starting to come out with hardware controllable via iPhone applications, so it's only a matter of time before one of the larger accessory providers creates something like what you want. If they expose a protocol for controlling the device, all you'll have to do is write your application to control the device via that protocol.