NUS only receives the first byte

[Kenan]

Hi,

I'm currently playing around with the NUS example in the SDK and still trying to understand how it works. My BLE event handler only receives the first byte of the string of bytes I send using a BLE debugger app on Android (BLE debugger by Syntronix), though, it receives all bytes if sent from the nRF Connect app. I have been using Syntronix's debugger for a while with no problems. 

What I care about the most here is knowing if there's any special implementation the nRF Connect is taking care of in the background while Syntronix's debugger app is not. 

FYI: nRF in our application is the peripheral and the central is an Android application.

[ox00]

	public void send(final String text) {

		// Are we connected?
		if (mRXCharacteristic == null)
			return;

		if (!TextUtils.isEmpty(text)) {
			final WriteRequest request = writeCharacteristic(mRXCharacteristic, text.getBytes())
					.with((device, data) -> log(LogContract.Log.Level.APPLICATION,
							"\"" + data.getStringValue(0) + "\" senttoMCU"));

			if (!mUseLongWrite) {
				// This will automatically split the long data into MTU-3-byte long packets.
				request.split();
			}
			request.enqueue();
		}
	}

This is the code for sending. Already try using UART toolbox apps and nrfblinky apps . 244 bytes is default transfer packet. Maybe the code in Syntronix's debugger app is the problem.

[Hung Bui]

Hi,

Could you capture a sniffer trace of the communication when you use the BLE debugger app ? 

It would reveal if the app only send one byte or not. 

I assume you have no problem when testing with the UART profile inside nRFToolbox ? 

[Kenan]

I'm receiving all bytes when using nRFToolbox. 
I'll try capturing the sniffer trace and get back.

From your answer I understand that there's no special drivers needed on the Android side to communicate over NUS. Right? This could be a problem with the debugger app.

[Hung Bui]

Yes, it's a very simple app, there is no special driver to send data to NUS. Please have a look at the source code of the nRFToobox here: https://github.com/NordicSemiconductor/Android-nRF-Toolbox