Separate transmit power setting for BLE and Thread when using MPSL

RE: Separate transmit power setting for BLE and Thread when using MPSL

Simonr — Thu, 29 Jul 2021 06:50:16 GMT

Hi Jon

The application must instruct the controller to change the TX power correctly. Have you checked out the set_tx_power() function in the hci_pwr_ctrl sample in the Zephyr SDK? This function should give you a good idea of how this should be done.

Best regards,

Simon

RE: Separate transmit power setting for BLE and Thread when using MPSL

Jon — Tue, 27 Jul 2021 17:47:56 GMT

Simon, will you be responding with more information about "the R&D team can confirm that Dynamic TX Power control is supported by the SoftDevice Controller" statement? Obviously we have not had any success getting TX power control to work on our end...

Thanks,

Jon

RE: Separate transmit power setting for BLE and Thread when using MPSL

Simonr — Thu, 22 Jul 2021 11:02:37 GMT

Again, sorry for the delays. This is due to the staff shortage during summer that Susheel has mentioned. He is taking some time off, so I have been assigned this case in his place. According to the internal thread we have on this, the R&D team can confirm that Dynamic TX Power control is supported by the SoftDevice Controller.

Best regards,

Simon

RE: Separate transmit power setting for BLE and Thread when using MPSL

Jon — Mon, 12 Jul 2021 22:37:43 GMT

Susheel,

Any update on this? I need to find a way to escalate this issue as we are nearing commitment to this design and need to ensure we will be able to continue to support the external FEM.

Thanks, Jon

RE: Separate transmit power setting for BLE and Thread when using MPSL

Susheel Nuguru — Tue, 06 Jul 2021 11:53:33 GMT

Hi,
Sorry for the delays and thanks for your patience. Very slim staffing due to summer holidays are contributing to the delays.

I have tried to set this up at my personal MacBook (which I never used for any NCS related things) and I did not manage to run docker correctly.

But I asked the R&D team for the SD controller to assist with some help and tare not sure if we support CONFIG_BT_CTLR_TX_PWR_DYNAMIC_CONTROL in the SD controller.

RE: Separate transmit power setting for BLE and Thread when using MPSL

Susheel Nuguru — Tue, 29 Jun 2021 08:22:06 GMT

Jon, We are thinly staffed due to summer vacation and I did not manage to test this yet and will be away second half of the day, so i will test this tomorrow earliest. Sorry for delays and I appreciate your patience.

RE: Separate transmit power setting for BLE and Thread when using MPSL

Jon — Wed, 23 Jun 2021 18:16:23 GMT

Okay, here is a project with a similar architecture to the project I am working on:

https://github.com/project-chip/connectedhomeip/tree/master/examples/lock-app/nrfconnect

The easiest way to get this project built (a summary of the Readme.md) is by performing the following steps on a Ubuntu or MacOS machine with docker installed:

1. mkdir ~/WORK_DIR

2. cd ~/WORK_DIR

3. git clone https://github.com/project-chip/connectedhomeip.git

4. mkdir nrfconnect

2. cd connecdhomeip

3. git submodule update --init

4. docker pull nordicsemi/nrfconnect-chip

5. docker run --rm -it -e RUNAS=$(id -u) -v ~/WORK_DIR/nrfconnect:/var/ncs -v ~/WORK_DIR/connectedhomeip:/var/chip \
-v /dev/bus/usb:/dev/bus/usb --device-cgroup-rule "c 189:* rmw" nordicsemi/nrfconnect-chip

[In the docker container]

A. $ cd /var/chip

B. $ setup

C. $ python3 scripts/setup/nrfconnect/update_ncs.py --update

D. $ cd examples/lock-app/nrfconnect

E. $ west build -b nrf52840dk_nrf52840

The built target code will be in (on the host machine):

~/WORK_DIR/connectedhomeip/examples/lock-app/nrfconnect/build/zephyr/zephyr.hex

and will be in (inside the docker container):

/var/chip/connectedhomeip/examples/lock-app/nrfconnect/build/zephyr/zephyr.hex

Once this code is flashed onto a nrf52840-DK, pressing BUTTON 4 on the DK will place the BLE into advertising mode.

I have found that the BLE advertisements ALWAYS are being sent at 0dBm.

Things I have tried:

a. setting BT_CTLR_TX_PWR_MINUS_20 in menuconfig

b. setting BT_CTLR_TX_PWR_DYNAMIC_CONTROL in menuconfig

Jon

RE: Separate transmit power setting for BLE and Thread when using MPSL

Jon — Wed, 23 Jun 2021 16:32:05 GMT

I don't think I can provide our project since it part of the CHIP (Matter) SDK development. If there is a BLE/Thread (on Zephyr) example you can point me to with the correctly-configured setup that I can evaluate I can probably work from there. Specifically, I need an example that:

a) Configures Thread transmit power at +0dBm

b) Configures BLE transmit power at -20dBm (e.g., advertisements are transmitted at -20dBm)

or alternatively

a) Provides some sort of callback from MPSL to the application layer before any Thread or BLE operations such that the the application can change power and/or reconfigure PA/LNA on FEM differently between BLE and Thread packets.

RE: Separate transmit power setting for BLE and Thread when using MPSL

Susheel Nuguru — Wed, 23 Jun 2021 13:18:45 GMT

Honestly speaking, I have not tried to control power with BLE/Thread combo in Zephyr, but CONFIG_BT_CTLR_TX_PWR_DYNAMIC_CONTROL should expose HCI commands to write and read the TX power. Can you give me your project and your attempt of writing these HCI commands so that I can try to dig into it and figure out what else needs to enabled for this feature to work.

RE: Separate transmit power setting for BLE and Thread when using MPSL

Jon — Tue, 22 Jun 2021 20:13:21 GMT

Update: I have also tried the following code in an attempt to alter the BLE TX power (tested by monitoring advertisement power levels). However, this code has no effect:

static mpsl_tx_power_envelope_t sEnvelope =
{
.phy = MPSL_PHY_BLE_1M,
.envelope = {-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6,-6}
};

mpsl_tx_power_channel_map_set(&sEnvelope);

FYI - I am using NCS/Zephyr along with OpenThread

Jon