Transmission interval smaller than 100ms without softdevice

[tomole]

Hi,

I need to send my packets with an interval smaller than 100ms in unconnectable mode. I know, that this is a restriction from Bluetooth standard. For my application it is ok not to use the standard. As I understand, in every softdevice there is a built-in limitation and no one can go lower than 100ms with the usage of them. In this case, it is clear that I need to program my nRF51 DK without softdevice. How can I do it? Does anyone have experience with it? Are there any examples available?

[Jørgen Holmefjord]

Hi,

You can have a look at the firmware of the Solar powered sensor beacon example application. This application is acing as a Bluetooth Low Energy beacon, without using a softdevice. You can find the source code of the firmware on GitHub.

Best regards,

Jørgen

[tomole]

Dear Jørgen, can you explain how can I run this example on nRF51 DK?

[Jørgen Holmefjord]

I have ported the advertising part of the example to UART example in SDK 12.2. You can find the source file here: beacon_no_softdevice_nrf51.zip. Unzip it under examples\peripherals in SDK 12.2 folder. Notice that I have only updated the Keil project file, found in pca10028/blank/arm5_no_pack, to include the correct files and defines. There is also a hex-file that you can test directly. If you use another compiler, you have to do some small changes. Here is a screenshot from my device doing non-connectable advertisement with 50 ms intreval: