Is BLE_GAP_PHY_CODED using the S=2 or the S=8 coding?

[Tobias Schneider]

Hi,

the nRF5 SDK v13.0.0-1.alpha uses the BLE_GAP_PHY_CODED constant to indicate a coded PHY.

The BLE 5.0 standard specifies two options for coding: S=2 (500 kbit/s) and S=8 (125 kbit/s).

Which one of these does BLE_GAP_PHY_CODED enable?

Regards Tobias

[Sigurd]

Hi,

The BLE_GAP_PHY_CODED option enables S=8 coding (125 kbit/s), this is the option that will give you the longest range.

[Luke]

Hey, And how do I configure the S=2 (500 kbit/s)?

[Sigurd]

Bluetooth 5 specifies 3 new PHYs:

S=2, S=8 and 2Mbps.

If you want high speed you need to use the 2Mbps, and you if you want the longest range(4x longer) you should use S=8(BLE_GAP_PHY_CODED). S=2 is currently not supported by the SoftDevice, but we will hopfully add support for S=2 soon.

[Luke]

Thanks for the quick answer! Is there any example code to send packets (simple rx/tx) in the 125kBit(BLE_GAP_PHY_CODED) mode? I would like to test the percentage of throughput in difficult environment. Connected mode is not the best option to test that.

[Sigurd]

If you have 2 nRF52840-PDK you can use the ATT_MTU Throughput Example for that. What do you mean by "Connected mode is not the best option"? You will need to connect 2 devices(1 master/ 1 slave) to test the throughput.

Also take a look at this blog post here: devzone.nordicsemi.com/.../