Re: Bluetooth mcumgr SMP DFU speed #ble


Carles Cufi
 

Hi Nick,

 

What is your client device? i.e. the device sending the image. If it’s a Linux box running mcumgr there might be limitations there, but if it’s a mobile phone then you should definitely get faster speeds. Have you tried with different client devices?

 

Finally, please take a look at this configuration file that maximizes throughput:

https://github.com/NordicPlayground/fw-nrfconnect-nrf/blob/master/samples/bluetooth/throughput/prj.conf#L28

 

Carles

 

From: users@... <users@...> On Behalf Of nick.ward via Lists.Zephyrproject.Org
Sent: 15 October 2019 02:28
To: users@...
Cc: users@...
Subject: [Zephyr-users] Bluetooth mcumgr SMP DFU speed #ble

 

Hi all,

I'm trying to optimise the mcumgr SMP DFU transfer speed over Bluetooth LE.

I'm getting speeds up to 5.12KibB/s (with different combinations of devices) but this Punchthrough blog post claims up to ~50KB/s is possible:
https://punchthrough.com/maximizing-ble-throughput-part-3-data-length-extension-dle-2/

The Bluetooth code is all running on a nRf52832 module.
I'm using Zephyr 1.14.0
I've got scanning turned off


Other settings:

CONFIG_BT_L2CAP_TX_MTU=260

CONFIG_BT_RX_BUF_LEN=260

CONFIG_BT_CTLR_DATA_LENGTH_MAX=251

I'm using a connection interval of 7.5ms

I've experimented with other Kconfig Bluetooth options but none have improved it significantly.

Has anyone got any tips to increase this throughput they can share?

Is 5.12 KiB/s possibly the upper limit with Zephyr 1.14?

Thanks,

Nick

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