Radio test configuration nrf21540DK

[Muhammad Usman]

Hi JONATHAN LL 

I am using nrf21540DK, NCS version 2.3.0, Radio Test example, RSSI Viewer as a Scanner, and VSCODE studio as an IDE. 

I just come to know that. do not support the nrf21540DK configuration. I tested its RSSI and got -23dm @0 to 4 dbm input from nrf52840.

To confirm the communication between nrf21540 and nrf52840, I used an oscilloscope to monitor the SPI signals on P1.13, 14, and 15. But I got no signal.

After that when I loaded the supported "Direct test mode " example I got the pulses on these pins.

Can you please help me in this regard that how to make it work with the "Radio test" example? 

Above picture is when i tested it with Direct test mode.But no signals in case of radio test example.

Can you please help me in this regard? I tested my custom (nrf52833+nrf21540) board as well .And i faced the same issue with that as well.

Thanks & regards,

Muhammad Usman

[JONATHAN LL]

Update:

Setup with the nRF21540DK, Radio test example, with the following configs:

CONFIG_FEM=y

CONFIG_RADIO_TEST_POWER_CONTROL_AUTOMATIC=n

Using the Saleae logic pro to check the SPI lines. Connected to pin P1.13, P1.14 and P1.15 and I am able to see activity. 

Picture above is captured when the start_tx_carrier command is send.

uart:~$ output_power neg8dBm
TX power: RADIO_TXPOWER_TXPOWER_Neg8dBm
uart:~$ fem tx_gain 0
Front-end module (FEM) Tx gain set to 0
uart:~$ start_channel 40
Start channel set to: 40
uart:~$ start_tx_carrier
Requested tx output power: -8 dBm
Tx output power set to: -8 dBm
Start the TX carrier



This capture is with the below commands, capture is taken when tx_carrier command is sent. 


uart:~$ fem tx_gain 10
Front-end module (FEM) Tx gain set to 10
uart:~$ start_tx_carrier
Requested tx output power: -8 dBm
Tx output power set to: -8 dBm
Start the TX carrier
uart:~$




There is no activity on the SPI lines before the start tx is sent.


Here is a test where automatic power control was enabled



uart:~$ output_power neg12dBm
TX power: RADIO_TXPOWER_TXPOWER_Neg12dBm
uart:~$ start_tx_carrier
Requested tx output power: -12 dBm
Tx output power set to: -30 dBm
Start the TX carrier
uart:~$




For the nrf52833DK with the 21540EK:

SPI works here as well, you can see that there is the same type of action on the different SPI pins here:


uart:~$ start_channel 40
Start channel set to: 40
uart:~$ start_tx_carrier
Requested tx output power: 20 dBm
Tx output power set to: 20 dBm
Start the TX carrier
uart:~$



I have also used a nRF52DK connected to RSSI viewer app to confirm that the DUT is transmitting. 

Regards,
Jonathan

[Muhammad Usman]

Hi JONATHAN LL 

Thank you so much for your great support. I really appreciate the efforts you did for me.

I will test soon and update you as well about the results on my end.

Thanks & Regards,

Muhammad Usman