ble_nus_string_send error codes

[leonhart88]

Hi all,

I'm sending data with ble_nus_string_send() in a loop as shown below. If it returns an error it retries until it gets NRF_SUCCESS. I'm getting an error code 0x0013. Does anyone know what this means or where in the documentation this is stated? Thanks.

			for (int i=0; i<11; i++)
			{
				err = ble_nus_string_send(&m_nus, testData, &testDataLength);
				while (err != NRF_SUCCESS)
				{
					errorCounter++;
					err = ble_nus_string_send(&m_nus, testData, &testDataLength);
					SEGGER_RTT_printf(0, "Error encountered: %04x\n", err);
				}
			}

[Jørgen Holmefjord]

I don't have any exact details on overhead when calling it the way you do, but I would suggets that you follow the recommendation in the documentation and keep track of the queue size, and only call sd_ble_gatts_hvx when there is available space in the queue.

[leonhart88]

Hi Jorgen,

Thanks. I've modified it so at least when I encounter an error I set a flag until it gets cleared by the TX_COMPLETE event...so at least I'm minimizing the unecessary calls a bit.

Can you explain how to determine the queue size? I believe I read there was a function in the old SDK versions which would return this, but it's now configured via sd_ble_cfg_set.

I'm currently just using nrf_sdh_ble_default_cfg_set(). What is the default value for the number of tx buffers?

[Jørgen Holmefjord]

You will need to keep track of the value you passed to sd_ble_cfg_set. The default is, as documented in the infocenter, given by the symbol BLE_GATTS_HVN_TX_QUEUE_SIZE_DEFAULT.

[leonhart88]

Great thanks! I totally missed that last part in the documentation. Thanks for your help! Cheers.

PS is there a maximum queue size?

[leonhart88]

Also, am I able to call sd_ble_cg_set() after nrf_sdh_ble_default_cfg_set() to just modify the tx queue attribute? Or do I need to set up everything using sd_ble_cfg_set()?