ByteArray requestWrite

OK applied Jims answer....

https://forums.garmin.com/developer/connect-iq/f/discussion/210596/bytearray-encodenumber-example

	function notifyLocationChange( lati, longi, elev ){
		var locArray = new[12]b;
		var latiArray = new[4]b;
		var longiArray = new[4]b;
		var elevArray = new[4]b;
		if( _characteristic != null ){
			latiArray.encodeNumber(lati, Lang.NUMBER_FORMAT_FLOAT, null );
			longiArray.encodeNumber(longi, Lang.NUMBER_FORMAT_FLOAT, null );
			elevArray.encodeNumber(elev, Lang.NUMBER_FORMAT_FLOAT, null );
			locArray.addAll( latiArray );
			locArray.addAll( longiArray );
			locArray.addAll( elevArray );
			_characteristic.requestWrite( locArray, {:writeType => Ble.WRITE_TYPE_DEFAULT} );
		}
	}

but the hit log write exception????

Error: Unhandled Exception
Exception: Long Writes are not supported
Stack: 
  - notifyLocationChange() at C:\NordicSemi
RF5_SDK_15.3.0_59ac345\examples\Incus_Performance\garmin\NovaThingy\source\EnvironmentProfileModel.mc:46 0x10001108 
  - onPosition() at C:\NordicSemi
RF5_SDK_15.3.0_59ac345\examples\Incus_Performance\garmin\NovaThingy\source\PositionSampleView.mc:66 0x10000e87 

locArray is too large. You're creating a 12 byte array, then appending another 12 bytes to the end of it with the addAll() calls. The maximum size is 20 bytes but you're trying to send 24.

From the documentation for addAll():

"When adding an Array of Objects, the Array is expanded by the size of the provided Array, and all of the new elements are inserted starting at the new index."

So addAll is expanding to fit the contents of the new array, and sticking them at the end.

Initialize locArray to an empty array instead of a 12 byte array. 

Also, the documentation for ByteArray says the same thing. addAll() is really more of an "appendAll" operation.

locArray = new[0]b;

.....

locArray.addAll(latiArray);

locArray.addAll(longiArray);

locArray.addAll(elevArray);

..... 

Another option would be to create a byte array that's large enough and then use an :offset in encodeNumber

Super; used :offset option for the requestWrite; eureeka.....hit breakpoint in  peripheral; has received some location data.
I just now need to throttle the writeRequest; do one is finished before the next is requested.

It would also be good to limit the rate of location data arriving in the app.

Yes, you meed to do queueing.  The nordic sample does that, and I do it in the raspberry pi samples I posted:

https://forums.garmin.com/developer/connect-iq/b/news-announcements/posts/would-you-like-some-raspberry-pi-with-your-connect-iq

CommQueue.mc in the CIQ apps is the main code, and in the view I add to the queue, in the bledelegat, run the queue, etc..

I also have logic for time outs, so in the event you don't hear back, things reset.