nRF52832 - Direct Test Mode - Set the bandwidth to 2MHz

[ou_frankie]

Hi All,

Just feedback from Lab, they said that they can set any channel frequencies at bandwidth = 1MHz in the Direct Test Mode. BUT they said that they need to test any channel frequencies at bandwidth = 2MHz and do not know how to set it.

Please help to answer how to set the bandwidth to 2MHz in the Direct Test Mode.

Thanks.

Best regards,

Frankie

[bjorn-spockeli]

Hi Frankie, 

the DTM example uses a physical channel number between 0..39 (base 2402 MHz, Interval 2 MHz), this channel number is set by bits 8:13 of  a 16-bit DTM command that is sent over the UART interface. Hence, there should not be any issue with setting the channel frequency with a 2MHz bandwidth.

If they're only testing the PHY layer, then I recommend using the simpler radio_test example, see  nRF5 SDK v15.0.0: Radio Test Example. 

Best regards

Bjørn

[ou_frankie]

Hi Bjorn,

For the simpler radio_test example, I found that the following commands as follow picture and did not found any command for the set the bandwidth. Can you provide more detail how to use the following commands? Can you provide a example for set a channel frequency with 2MHz bandwidth (NOT SWEEP)?

Thanks.

Best regards,

Frankie

[bjorn-spockeli]

You set the frequency by setting the start channel using the "a" command. You are then prompted to enter a channel number between 00 and 80. The frequency will then be 

Frequency = 2400 + channel number (MHz).

To then start the RADIO in TX mode with a constant carrier you input the "c" command, Start TX carrier. If you want to receive on the configured frequency you enter the "x", Start RX carrier". If you want to turn of the radio you enter the "e", Cancel sweep carrier command. 

Best regards

Bjørn 

[ou_frankie]

Hi Bjorn,

Noted and thanks.

Best regards,

Frankie

[chcnuhk]

Hi,

It seems you are talking on changing the transmit frequency.

How to change the modulation bandwidth from 1MHz to 2MHz in the DTM code?

BR,

Charles

[jing]

You can issue the DTM Test Setup Command as defined in the Bluetooth Specification v5 (Vol6, Part F) to select your desired PHY.

jing