RF Testing of nrf52840 DK using CMW500

[Venkata Bharath]

Hi,

Can you please help in connecting the nrf52840 DK with CMW500 and to measure the RF power at different levels of nrf. (For example, at 8dBm, 4dBm, 0dBm, -40dBm).

In this testing i need to see the RSSI values at the CMW500 of nrf board.  

Please help in both process connection mode and non-connection mode.

[Bendik Heiskel]

Hi,

The CMW500 supports Buetooth testing using direct test mode(DTM).

Rohde & Schwarz have a video guide on configuring the CMW for Bluetooth testing:
https://www.rohde-schwarz.com/us/knowledge-center/videos/how-to-perform-bluetooth-5-testing-with-the-r-s-cmw-test-platform-video-detailpage_251220-565523.html

 

Best regards,

Bendik

[Venkata Bharath]

I have checked this.

Can you please let me know connections between CMW500 and nrf52840?

CMW500 is not detecting the EUT.

I have flashed DTM only.

I have used USB to serial bridge, connecting pin P0.08(Rx) to adapter side Tx. and P0.06(Tx) to adapter side (Rx).

And connected the USB to CMW500 to power on the nrf Board.

Please let me know any mistake in this process.

[Venkata Bharath]

Hi Bendik Heiskel ,

Now i am able to do the connection but problem is i am not able to transmit 8dBm Tx power, it is coming as 0 dBm. 
May i know what do to to transmit 8dBm power?

[Bendik Heiskel]

To configure the output power you can use the direct test mode command 0x09 followed by the TX power in dBm.

The DTM commands are a part of the Bluetooth Core Specifications, they are described in Volume 6 Part F:
https://www.bluetooth.com/specifications/specs/core-specification-6-0/

I am not sure if it is possible to send individual commands using the CMW500, or if you need to modify the test parameters to change the TX power, I can unfortunately not assist with that. I recommend you reach out to Rohde & Schwarz for support for configuring the CMW500.