SoftDevice S140 vs S113 memory size when used on nrf52840?

[GerardB]

We are developing a product based on nrf52840. The product will always be configured as a BLE peripheral. We need to be able to use OTA for both SoftDevice & Application code.

From what I read we could use either the softDevice S140 or S113. The S113 specs state that it is "memory optimized for a BLE Peripheral Only device". So it seems that is the softDevice we should select for our project

Questions:

1. Is my assumption correct (ie: S113 would be the correct choice given we only need the BLE Peripheral functionality)?

2. What exactly is the difference in memory usage/footprint between the S140 and the S113 SoftDevices?

3. Any other issues or limitations or differences/comments we should be aware of?

Thanks!

Gerard

[Vidar Berg]

Hi Gerard,

1. Most peripheral applications will be fine with the smaller s113 Softdevice. It's only if your application requires support for either "BT Long range" or "Advertising extensions", then you will need to select the s140 as those features aren't included in the s113 (is part of the memory optimization to remove those features).

Here is table showing what features are supported for our different Softevice variants:

(https://www.nordicsemi.com/Products/Bluetooth-Low-Energy/nRF5-SDK-and-SoftDevice)

2. Please take a look at the "Memory layout" section of the bootloader documentation. This section illustrates how much space will be left for the application based on what device and Softdevice variant you have. You can also use the Softdevice release notes to find the memory footprint fo a particular Softdevice release.

3. There is not anything I can think of.

Best regards,

Vidar