AVRCP key events handled in linux - linux

AVRCP key events are handled in bluez within avdtp file which invokes uinput module in kernel. Can anyone suggest me how these key events are send to application to play/pause/rewind , is any key listener present which sends these key events to respective applications or if applications listen to key events, do they need to subscribe to some service?
Thanks in advance

depending on which blueZ version you are using, you can do following,
take a look at the test of blues for single-endpoint. there is implemented a Control interface, and if you use some tool like Dfeet, then you can see the interfaces related to it, so that you can call stop, play, next commands...

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HM-10 BLE Module - connect to other Devices

first of all: What i am trying to do is only for private interest.
I'd like to connect a AT-09/HM-10 BLE-Module with Firmware 6.01 to another device which provides also a BLE Module, which it is not based on the CC254X-Chip,
I am able to communicate with this Device using my Laptop with integrated Bluetooth, Linux and the bluepy-helper. I am also able to make a connection using the HM10 through a USB-RS232-Module and "Hterm", but after that quite Stuck in my progress.
By "reverse-engineering" the Android-Application for controlling this particular device i found a set of Commands, stored as Strings in Hex-Format. The Java-Application itself sends out the particular Command combined with a CRC16-Modbus-Value in addition with a Request (whatever it is), to a particular Service and Characteristic UUID.
I also have a Wireshark-Protocol pulled from my Android-Phone while the application was connected to the particular device, but i am unable to find the commands extracted from the .apk in this protocol.
This is where i get stuck. After making a connection and sending out the Command+CRC16-Value i get no response at all, so i am thinking that my intentions are wrong. I am also not quite sure how the HM-10-Firmware handles / maps the Service and Char-UUIDs from the destination device.
Are there probably any special AT-Commands which would fit my need?
I am absolutely not into the technical depths of Bluetooth and its communication layer at all. The only thing i know is that the HM-10 connects to a selected BLE-Device and after that it provides a Serial I/O and data flows between the endpoints.
I have no clue how and if it can handle Data flow to certain Service/Char UUIDs from the destination endpoint, althrough it seems to have built-in the GATT , l2cap-Services and so on. Surely it handles all the neccessary communication by itself, but i donĀ“t know where i get access to the "front-end" at all.
Best regards !

Using PubNub, is Unsubscribe a dual use command for Publish and Subscribe?

Yes, I know it seems like a simple question but I just recently started using PubNub and I am confused on how to disconnect from a channel. I think the command to use is "Unsubscribe" and my misunderstanding relates to the dual use of the word.
Logically, I understand that once you initialize PubNub and publish a message a separate process can subscribe to the establish channel. When it's done it unsubscribes. Got it!
Now we want to completely disconnect from PubNub. That is end the channel.
Do I use the command "Unsubscribe" to do this? I guess I am logically looking for an "End" or "Disconnect" command and not an "Unsubscribe" command because it did not subscribe to the channel, it established the channel. I know it seems petty but until I understand this it's difficult to move forward. So is this a dual use command?
Thanks
You are on the right track here. Depending on the client platform in question, an unsubscribe resulting in an empty channel list will completely disconnect you.
On the more sophisticated clients, advanced/smart frameworks, there are the API calls of un/subscribe (which as you described subs /unsubs you to a specific channel), and separately, the public and/or private method calls defining/detecting being "connected" or "online".
For example, iOS has specific connect and disconnect calls, separate from subscribe/unsubscribe calls. On JS, there is no explicit connect/disconnect, but regardless if you are subbed or not to an active channel list, there may be background "pings/heartbeats" being made to the PN cloud to detect connectivity/online/offline state.
If you give more info on the client platform and version you are on, we can give you more info on how to completely sever all connects to the PN cloud and achieve a "complete disconnect".
geremy

How to handle external events in CQRS?

Supposed I have a CQRS-based system with a web UI that I want to integrate with some external device, let's say an Arduino board.
Basically, I can think of three scenarios:
When the user clicks on a button in the web UI, the Arduino shall do something.
When the user pushes a hardware button, the domain shall react and the UI shall update.
When the user pushes a hardware button, the UI shall update.
How do I model these scenarios?
This is quite easy IMHO: UI emits a command, business logic runs, emits an event, and Arduino is listening for events. Basically, the Arduino is nothing but an event denormalizer. Is this the correct approach?
This is quite easy IMHO as well: Arduino emits a command, sends it to the command bus, and the same procedure runs as with scenario 1. Basically, there's no difference for the CQRS-system whether the command comes from the web UI of from anything else.
This is where I'm really unsure: Supposed the Arduino handles the button press itself, and flashes an LED in response. I just want to make sure that my application takes notice of "the LED has been flashing". This is no command (as the flashing already happened), instead it's an event. What do I do with this event? Do I simply store it in the event store and bypass my domain? This seems horribly wrong to me. Do I emit a pseudo-command which is turned 1:1 into a matching event? This will work and does not bypass the domain, but it feels wrong as well, as it actually is no command. What should I do?
Any advice on these things?
1.Just use an event handler( updating ui maybe using websocket ) listening on Arduino event if no state should change in your domain.
2. Use a saga listening on Arduino event and fire a command if state should change in your domain.
UI is not a domain concern. So I prefer option 1.

How to handle external and internal event in j2me

i am developing game in j2me. In that i have to handle external and internal event.. I studied in some of websites that we can handle the event with the help of hidenotify() and shownotify().
But it dont know where to use these two methods? whether in hidenotify() in pauseApp() and shownotify() in startApp() or somewhere else..
Please anyone give me a clear idea about handling the event in mobile.
In J2ME world, external events resemble the following:
In coming SMS message. This is used trigger application specific action caused by a message sent from a pre-defined and well known sender. This feature is known as "push".
Media card inserted and the application needs to recognize it and act upon it.
If the phone is NFC enabled, launching an application when the phone is taken to a card reader.
When a server is attempting to connect to the phone, launch the application and perform some specific action. This requires that phone is addressable on network; very few of them support it.
Launching the application at a specific time.
I hope you get the idea. Most of the above are achieved by making use Push Registry.
The events that you are talking about are the callbacks to application that AMS (Application Management Software) notifies before the component is being shown and before the component is being hidden.
And pauseApp will be called by AMS when the application is about to be paused; this typically happens when there is an incoming phone call, or the flip is closed (on a flip phone) etc.
Hope it answers your question.

Sending SMS using Java ME application

I want to a Java ME application that transfers any SMS received to a PC using bluetooth. The PC can then direct the Java ME application via bluetooth to send a response SMS. Is there library available for this architecture or I have to design it myself?
Is this approach correct or a better one exists? I want to use bluetooth as then I will not have dependency on the cable.
You'll need to create this yourself, however you'll find that you can't do what you want with J2ME.
J2ME can't access any old SMS that the handset receives, only ones sent to a specific port upon which the MIDlet is listening. So to get all the other SMSes, create a bluetooth serial/dial-up connection to your handset in the way I've described in this answer.
Create a PC client which repeatedly issues AT+CGML commands (as described in the AT command set document linked to in the answer above), to see when an SMS has been received. Use AT+CGMR to read and parse the message text. Then use AT+CGMS to sent a response. This can all be done over bluetooth.
It's better to use the serial connection to send a response, because a MIDlet cannot usually be triggered to open based on incoming bluetooth data.
Hope this helps.
You may have already achieved your task, anyway for the reference I think it is much better if you try using Gammu . I'm using it for the same task (Send / receive SMS through PC ) with a simple bat file I have written, works like a charm.
Anyway you don't need any J2me program for this.
Wammu takes care of making the connection to phone and sending AT commands.

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