# \[Ketai library bluetooth\] Can I know if it is connected?
**URL:** https://discourse.processing.org/t/ketai-library-bluetooth-can-i-know-if-it-is-connected/45066
**Category:** Processing for Android
**Created:** [September 19, 2024, 11:26pm UTC](https://discourse.processing.org/t/ketai-library-bluetooth-can-i-know-if-it-is-connected/45066 "2024-09-19T23:26:54Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@GWAK](https://discourse.processing.org/u/GWAK)
#### Post date: [September 19, 2024, 11:26pm UTC](https://discourse.processing.org/t/ketai-library-bluetooth-can-i-know-if-it-is-connected/45066/1 "2024-09-19T23:26:54Z")
[Ketai library bluetooth] Can I know if it is connected?
Hello. Nice to meet you.
The reference source code is as follows. (Example code)
[http://ketai.org/examples/bluetoothcursors/](http://ketai.org/examples/bluetoothcursors/)
[http://ketai.org/reference/net/ketaibluetooth/](http://ketai.org/reference/net/ketaibluetooth/)
Connect to Bluetooth through
> bt.connectToDeviceByName(selection);
> 
At this time, is there a variable or method to find out whether the connection is successful?
---
### Author:  [@svan](https://discourse.processing.org/u/svan)
#### Post date: [September 20, 2024, 12:45am UTC](https://discourse.processing.org/t/ketai-library-bluetooth-can-i-know-if-it-is-connected/45066/2 "2024-09-20T00:45:00Z")
If the information provided by the ketai library in your original post is insufficient, one possibility is to add _onBluetoothDataEvent():_
```auto
//Call back method to manage data received
void onBluetoothDataEvent(String who, byte[] data) {
println("Connected.");
}
```
---
### Author:  [@GWAK](https://discourse.processing.org/u/GWAK)
#### Post date: [September 20, 2024, 4:33am UTC](https://discourse.processing.org/t/ketai-library-bluetooth-can-i-know-if-it-is-connected/45066/3 "2024-09-20T04:33:40Z")
Dear svan @svan
Thank you for your reply.
1.
By the way,
Is there a way to check if it’s still connected?
(Or maybe just keep checking it periodically?)
1.
Your answer has changed.
I understand what you mean.
Thank you.
---
### Author:  [@svan](https://discourse.processing.org/u/svan)
#### Post date: [September 20, 2024, 5:36am UTC](https://discourse.processing.org/t/ketai-library-bluetooth-can-i-know-if-it-is-connected/45066/4 "2024-09-20T05:36:37Z")
`Your answer has changed.`
I couldn’t get the first answer to work correctly. It was reporting the connection as false when I called _connectToDeviceByName()_ because the connect thread had not yet fired apparently. If it could have been checked a few seconds later (after the connect thread had fired) it would have worked. There is also an _isConnected_ boolean with KBluetoothConnection but I was unsuccessful in calling that also, for reasons unclear to me. There is a jar file for KBluetoothConnection in the library. With the technique that I posted, you know that you are connected when you see data being printed in the console log. Ideally _isConnected_ could be checked periodically; the data is there if we can just get to it.
**Alternate method:**
Add a button to your app to check for connection device with this code:
```auto
ArrayList devices = bt.getConnectedDeviceNames();
for (String device : devices) {
println("connected to :",device);
}
```
---
### Author:  [@GWAK](https://discourse.processing.org/u/GWAK)
#### Post date: [September 20, 2024, 8:29am UTC](https://discourse.processing.org/t/ketai-library-bluetooth-can-i-know-if-it-is-connected/45066/5 "2024-09-20T08:29:53Z")
@svan
Thanks for your thoughts.
```auto
boolean BLUE_EN = false;
if(TIMER_CHECK < millis()){
TIMER_CHECK = millis() + (long)5000;
BLUE_EN = bt.connectToDeviceByName(selection);
}
```
I solved it like this. Thank you.