nrf52840 as BLE peripheral

[Liam Richardson]

Hello,

I'm working on a BLE app on an Arduino Nano 33 BLE, which is equiped with an nrf52840. I'm struggling to increase my BLE transfer speed ( i think due to the limitations of the arduino library ).

At the moment i am updating a GATT caracteristic value with notifications, on my arduino (peripheral device) and reading the value changes from a central device (PC). PC is equiped with Bluetooth 4.2.

The problem is, i cannot change the carateristic value very quickly.

Can i do this more quickly by writting to the registers ?
Any other solutions for faster BLE transfer with my setup ?

Thanks

[Jørgen Holmefjord]

Hi,

Most likely, you would not increase the speed by writing any registers directly. The limiting factor is most likely in the Bluetooth link and not in the CPU. I assume you do not want to write your own Bluetooth stack.

Our softdevice is highly configurable. You can probably change some configs in the Arduino libraries you use to make the transfer faster, but it depends on what is exposed and what kind of throughput you are currently getting. This is anyway a question you need to direct to the developers of the Arduino library, as this is not being developed or supported by Nordic.

You can find expected throughput numbers for the softdevice with different BLE configurations in the softdevice specifications.

Best regards,
Jørgen

[Liam Richardson]

Thanks Jorgen,

I've found out that my limitation is the MTU size which is 23 bytes, set by the Arduino library.

Anyway i can override that ?

Thanks,

Liam

[Jørgen Holmefjord]

If there is no configuration API available in the Arduino library, you will have to modify the Arduino library itself. I recommend contacting the developers of the library to get help with this.