I am driving some experiments with a pair of a-JAYS Four headphones (having 3 buttons on its wired remote/mic) plugged onto a Galaxy Nexus (ICS 4.0.2).
My issue is that only the middle button is 'recognised' by a test app I have written, i.e. triggering both Intent.ACTION_MEDIA_BUTTON and/or Activity.onKeyDown callback with KeyCode 79 when it is pressed.
Pressing the two other buttons don't trigger any of the previous methods. For info, those headphones and its 3 buttons work on Apple iPhones and Apple computers (at least a MacBookPro 2011), as advertised on the box...
Firstly I thought Android or my device could simply not handle more than one button on a wired jack remote (even if that sounds weird...) but then I had a try with a pair of headphones from HTC (the ones coming with one of their Desire device) having 3 buttons. Middle button would react the same way as my a-JAYS, but the two other buttons are also recognised with KeyCodes 87 and 88, respectively Play Previous and Play Next media keys.
So it seems that either the device or the low levels layers of Android are simply not able to catch certain headphones buttons signals :/ (at least those which are not 87 and 88)
Any idea anyone about how to make Android able to recognise other buttons/signals from such headphones as Apple compatible ones? Would it imply low levels drivers writing for ICS or am I missing something really obvious?
Any help would be much appreciated. Can post my test-app code if needed.
Cheers
The signals/ resistance from the volume control buttons (1.525-1.495 V for volume down, and 1.619-1.587 V for volume up) are currently unable to be recognized through the android framework's software. I believe this has to do with Apple having a patent on the designated volume controls and so Google won't release to developers how the framework recognizes particular signals through the fourth connector on the headphone jack. The center/mic/action buttons on headsets generally work, it shorts the path from ~2V to ~0V and Apple does not own the patent for that. If someone could figure out how to interact with the inputs on their own that would be huge. I am tempted to learn app development and find a workaround.
The problem is more complicated that it seems: http://david.carne.ca/shuffle_hax/shuffle_remote.html .
I have to emphasize that I am no expert on this topic, but from what I have read and tried so far I conclude that it is not impossible to have an Android phone respond to an iPhone headphone's volume buttons, but for some reason the performance is poor/lagging.
There are some apps trying to do the magic, but they are too unreliable for everyday use. I suppose the problem is that triggering the signal may have to be implemented at a lower OS level than most regular apps have access too.
The solution could probably be some kind of a ROM mod...
If you can implement this, I am sure it would be a big deal for the Android community, and maybe a good biz for you.
Kind Regards, your fellow Hungarian
Gergő
You have to press and hold the middle button while plugging the headphones to the jack. That will make the microphone work on an Android. It works on my HTC Thunderbolt.
I believe it's a hardware issue (at least in regards to Apple headphones). If you look at the plug on those they have four contacts instead of the normal three. I'm willing to bet they run their button signals through that extra contact. AFAIK, there is no Android equipment wth jacks to match that.
So, ultimately I don't believe you can make apple earphones with buttons work for android (as far as button functions go).
You have to hold the middle the whole time for it to work. If you let go and not playin music it says accsessary not supported but if u play music and let go it simply stops the music until you hold it again. Maybe tape the middle button shut really tight?
If you look at the four contacts, tip-ring-ring-sleeve (TRRS), and know that MOST headphone sets are:
tip: left
ring 1: right
ring 2: ground
sleeve: mic
(1/4 inch pro audio stereo plugs are known as TRS - tip-ring-sleeve)
although some reverse the ground and mic contacts, what you need to know as far as how the device recognizes the different buttons you have, is that those buttons are making a short between the ground and mic contacts.
(before IR, old school WIRED remotes for VCRs used resistance for different functions)
Now your homework to find out what is going on is:
measure the resistance between ring 2 and the sleeve for each one of your buttons
find out if it is a momentary short, or constant
if you have some other headphone/mic device that works correctly, measure those impedance (resistance) too
I don't know how into this you want to get, but you can buy resistors with the correct impedance to get the functions you want out of the Android device, the question is, do you know what functions the device is capable of, and what those impedances are that trigger that function.
daniel#destinypatrolsoftware.com
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I am working on a game app. Like all game apps, it renders two side-by-side views. I would like to support using a bluetooth or OTG mouse in my app. So, I need to hide the normal mouse pointer.
I have done a bit of searching, but can not seem to figure out how to do this. I did find something that says Android 7.0 is getting a new API for custom pointers:
http://www.androidpolice.com/2016/06/16/android-n-gets-support-custom-mouse-pointers-via-new-api-dev-preview-4/
That's great, and would probably allow me to make a blank custom pointer.
But I need this to work on my current hardware with Android 6. And I know it's possible, because the other device does hide the mouse pointer.
Any tips or tricks to achieve this would be most welcome.
We’re porting to Android some interactive iOS apps used to teach young children with learning disabilities. We have hit a major usability issue, because we can't figure out how to disable physical or on-screen navigation buttons (Home and Recent Apps).
Before anyone says “you don’t want to do that”, we fully understand why you would always want these buttons enabled for an able-bodied adult, but these children pose a unique set of accessibility issues. Specifically:
Their fine motor control may be poor - they may inadvertently touch a different area of the screen to the area they intend, or accidentally use more than one finger at once.
They may have weak muscle tone and poor physical strength – so e.g. the bottom of the palm of their hand may drop and touch the screen while trying to just use a finger.
They struggle to achieve and easily become disheartened or disruptive if they fail.
For instance, a typical 5 year old child with Down syndrome will accidentally drop out of the app they are using as a result of inadvertently touching the Home button: when this happens repeatedly, and the adult teacher or parent has to go back into the app for them repeatedly, the child loses interest and focus. Another typical scenario is a young child with Autism, who may freak out completely and need physically restraining if this happens while using their favourite app. Also, many disabled children will try to poke any other button they can find, in search of a response. In any of these situations, a potentially valuable educational session may have to be completely abandoned.
We're aware of SYSTEM_UI_FLAG_HIDE_NAVIGATION and SYSTEM_UI_FLAG_LOW_PROFILE, but these only reduce the visibility of the on-screen buttons until the child touches some other part of the screen, and then they re-appear in a way that’s more distracting than if they were visible all the time.
On iOS there is the “Guided Access” feature that solves this problem trivially. Can we emulate anything similar on Android?
On iOS there is the “Guided Access” feature that solves this problem trivially.
Guided access appears to be a device setting, not something that developers enable unilaterally themselves, thank heavens.
Can we emulate anything similar on Android?
There is no similar device setting in stock Android.
You can download the Android source code, modify it as you see fit, build the results into a ROM mod, and install that ROM mod on devices as you see fit.
Or, you can perhaps work with a device manufacturer creating tablets aimed at children to see if either they have already added this capability to their devices, or would be willing to work with you to add such a capability in a future iteration of their devices.
I have an Android device into which a gamepad can be connected (it's a totally standard XBox 360 controller, but I need to support other varieties as well). The gamepad is showing up as a InputDevice with some analogue axes and some buttons.
I need to be able to query Android to find out what buttons the gamepad supports. Does anyone know how to do this?
I know that the system has this information, because if I write a command-line app which opens /dev/input/event... and queries the buttons using the EVIOCGBIT ioctl, I get a nice list of supported buttons from the kernel. But I can't do this from an Android application because I don't have permission to access the input devices directly.
It looks like it should be possible to get the InputDevice's KeyCharacterMap object and query that; but it looks like Android has attached the default QWERTY keyboard keymap to the gamepad, rather than constructing one that actually matches what the gamepad supports. This will happily tell me that the gamepad has a Q key, which it doesn't, and that it doesn't have a BUTTON_X key, which it does, and for which I am receiving key events. So that's not helping.
Is there any way to do this?
I haven't figured out a way yet, but I have found a horrible workaround.
If you call KeyCharacterMap.deviceHasKey(keycode), I can ask Android if any input device on the system supports the specified keycode. By iterating through all possible buttons that can occur on a gamepad (usefully, they're all called KeyEvent.KEYCODE_BUTTON_something), I can figure out that any connected gamepad must support at least some of these buttons.
It's not a very nice solution --- if I have an XBox 360 controller and a Wiimote connected at the same time, then I can't figure out that the XBox controller does not have buttons 1 or 2, and the Wiimote does not have X or Y, for example. But at least it's a start.
If anyone has any better ideas, please suggest some...
Here's what I need to do. I want to use an Android tablet for science research, but I will need to programmatically control the screen/backlight. Specifically, there is a mode where my app will need to communicate with other systems via WiFi, play sounds, and have the touchscreen active, but the backlight must be completely off; in this mode, the device cannot emit any light, or it will interfere with the science. Obviously, this cannot be sleep mode! Is this feasible?
I've looked around a bit, and this sounds really promising, but it isn't crystal-clear (to me, anyway!) whether this will work. Can anyone vouch for that?
Finally, does it matter which tablet I choose? Basically, there seem to be three possibilities: the backlight is controlled with a switch (doubt that is done anymore), the CPU can only turn it on or off, or the CPU can adjust it fully. Writing this makes me feel rather silly about being concerned, but a Samsung rep yesterday told me I can't do this on the Galaxy. Anyone care to recommend a tablet?
Thanks!
Specifically, there is a mode where my app will need to communicate with other systems via WiFi, play sounds, and have the touchscreen active, but the backlight must be completely off
Android does not support "have the touchscreen active, but the backlight must be completely off". And, you do not have the ability to turn the backlight "completely off" programmatically.
I've looked around a bit, and this sounds really promising
That sets the backlight to be low. Some devices may elect to turn the backlight off when it is set low. That is up to the device manufacturer.
Finally, does it matter which tablet I choose?
See above.
Since its a science research I'm going to assume you may not need to divulge this application and want it in a controlled environment. If this is the case, a little creative thinking suggests that since the touch screen will still react to even if covered by a thin layer of plastic (like the screen protectors for instance) you may be able to apply some opaque vinyl on top of the screen (easy to remove) for doing the experiments.
This may not be useful but since to me it sounded like it could I thought I'd share my thoughts with you on this one. Once you've covered the screen with the vinyl, the rest is as usual, keep screen on, and do your magic.
:)
I'm looking for a way to grab trackball events while the screen is off, preferrably on a N1. I'm building my own music player and would love to add the feature to skip songs by trackball press, without having to unlock my device everytime.
I've found TrackBallSkip, however the source code has been taken down and integrated into CyanogenMod. I fear that I may need to do something exotic to my phone (root it, mod it, whatever). While this isn't a problem, I would be happier if I could freely share my Music player.
Can anyone confirm that I'll need to mod the home to get access to this functionality? Or can I just straight code it (if so, any pointers in the right direction would be amazing).
Thanks!
I found where Cyanogen put TrackBallSkip into their source base (this commit). It appears to reside in phone/com/android/internal/policy/impl/PhoneWindowManager.java which means it can't be implemented without modding the firmware (since the related package resides in /system).