BLE DFU Speed difference between SDK14.2 and SDK15.3

RE: BLE DFU Speed difference between SDK14.2 and SDK15.3

Hung Bui — Fri, 28 Aug 2020 09:21:24 GMT

Hi Himasu,

If you are using nrfutil, please make sure you used the latest version and the softdevice you used for the firmware is >3 . You can find the code where longer data length is requested here: https://github.com/NordicSemiconductor/pc-nrfutil/blob/master/nordicsemi/dfu/dfu_transport_ble.py#L170

On the bootloader side we don't set a certain data length but simply follow what's requested and max supported. Check BLE_GAP_EVT_DATA_LENGTH_UPDATE_REQUEST event inside ble_evt_handler() in nrf_dfu_ble.c

RE: BLE DFU Speed difference between SDK14.2 and SDK15.3

Himansu — Fri, 28 Aug 2020 05:21:37 GMT

Hi,

Query: How to Enable Data Length Extension using Application nRF Util?

- Peripheral Device:
nRF52840 Chip-set

- Central Device:
nRF52840 DevKit

- Central Device controlled using Application nRF Util which is useing for testing:
github.com/.../pc-nrfutil

- Used Command:
nrfutil dfu ble -ic NRF52 -pkg E:\App.zip -p COM6 -n "DFU" -f -mtu 247

Regards,

Himansu

RE: BLE DFU Speed difference between SDK14.2 and SDK15.3

Hung Bui — Thu, 27 Aug 2020 15:52:02 GMT

Hi Himansu,
I can see that at test 2 you are achieving quite a good speed of transmitting. However I don't see using data length extension. This resulted in that the length of a packet is only 23 bytes (27 with the header). If you can update the data length extension (LL_LENGTH_REQ) you may be able to achieve faster DFU transmitting.

Regarding case 3, I think what can be improved here is that instead of requesting min interval of 7.5ms (which will not be accepted by iOS) you can try to request min 30ms max 50 ms for example. Then you will have more chance being granted 30ms , this is much better than 90ms as in your trace.

In addition, there was quite a lot of retransmission in the trace, seems that the communication was interfered quite a lot or the antenna/radio was not tuned on the NRF52840 DUT board you have. I don't see that problem in the test 1 and test 2.

RE: BLE DFU Speed difference between SDK14.2 and SDK15.3

Himansu — Thu, 27 Aug 2020 15:25:26 GMT

Hi,

I have taken sniffer log for issue and updating here.

We have use iphone 11 with latest iOS. so, DFU time is reduce and achieve 175 seconds. still we want to reduce this time. Please suggest any method or any other parameter we can change in phone app or bootloader. so, we can achieve less time compare to 175 seconds. Pleas suggest any applicable solution for achieve minimum time for app update.

We have do 3 test and result and sniffer log file name here.

MCU : nRF52840
SDK : SDK15.3
Softdevice : s340_nrf52_6.1.1_softdevice (SDK15.3)

DFU Test Cases and Sniffer log
Test#	Peripheral	Central	Conn Interval	DFU App Size	Observered Param	DFU Time	Sniffer Log File Name
1	nRF52840 Chipset	nRF52840 DevKit	Conn. Interval = 30 msec	241 KBytes	PHY1M, Conn. Interval = 30 msec	158 sec	Test1_nRFDevKit.pcapng
2	nRF52840 Chipset	nRF52840 DevKit	Conn. Interval = 7.5 msec	241 KBytes	PHY1M, Conn. Interval = 7.5 msec	122 sec	Test2_nRFDevKit_Set7p5ConnInt.pcapng
3	nRF52840 Chipset	iPhone 11		241 KBytes	PHY2M, Conn. Interval = 90 msec	174 sec	Test3_iPhone11.pcapng

Thanks,

Himansu

devzone.nordicsemi.com/.../Test3_5F00_iPhone11.pcapng

devzone.nordicsemi.com/.../Test2_5F00_nRFDevKit_5F00_Set7p5ConnInt.pcapng

devzone.nordicsemi.com/.../Test1_5F00_nRFDevKit.pcapng

RE: BLE DFU Speed difference between SDK14.2 and SDK15.3

Hung Bui — Wed, 05 Aug 2020 13:52:05 GMT

Hi Sandip,

Please try to get the actual connection interval when the DFU is transmitting. It's the p_ble_evt->gap_evt.connected.conn_params. min_conn_interval value when you receive BLE_GAP_EVT_CONNECTED event inside ble_evt_handler()

Or you can capture a sniffer trace. It gives more information with the sniffer trace.

RE: BLE DFU Speed difference between SDK14.2 and SDK15.3

SciTER Development Team — Tue, 04 Aug 2020 10:52:23 GMT

Hung Bui

Following is our connection parameter. Is there any wrong?

// <h> BLE DFU connection

//==========================================================
// <o> NRF_DFU_BLE_MIN_CONN_INTERVAL - Minimum connection interval (units).
// <i> Minimum GAP connection interval, in 1.25 ms units.

#ifndef NRF_DFU_BLE_MIN_CONN_INTERVAL
#define NRF_DFU_BLE_MIN_CONN_INTERVAL 6 //12
#endif

// <o> NRF_DFU_BLE_MAX_CONN_INTERVAL - Maximum connection interval (units).
// <i> Maximum GAP connection interval, in 1.25 ms units.

#ifndef NRF_DFU_BLE_MAX_CONN_INTERVAL
#define NRF_DFU_BLE_MAX_CONN_INTERVAL 80 //12
#endif

// <o> NRF_DFU_BLE_CONN_SUP_TIMEOUT_MS - Supervision timeout (ms).
// <i> GAP connection supervision timeout, in milliseconds.

#ifndef NRF_DFU_BLE_CONN_SUP_TIMEOUT_MS
#define NRF_DFU_BLE_CONN_SUP_TIMEOUT_MS 4000 //6000
#endif

// </h>
//==========================================================

Thanks,

Sandip Divani

RE: BLE DFU Speed difference between SDK14.2 and SDK15.3

Hung Bui — Thu, 23 Jul 2020 13:48:14 GMT

Hi,

12 to 15 minutes is a lot.
There must be something wrong here. I suspect that the connection interval was set to too large.
Could you please check the connection interval when doing DFU ?

As sniffer trace could be useful to reveal what caused the long DFU.