NRF52833 BLE Radio Test Issue

[MCM]

Hi,

We are using NRF52833 as a BLE central in our latest product and is undergoing radio certification tests. We are using SDK16 Radio Test example for the tests. 

The test lab wants us to transmit individually on the three BLE channels, but we realized that the radio test example does not set any frequency below 2405MHz. So here are my queries.

1. How do we use the radio test example to set tx carrier frequencies to BLE frequencies 2402, 2426 and 2480? If we can't use this firmware then is there any other firmware provided by Nordic for this purpose?

2. How does the BLE Softdevice set the channels to the correct BLE frequencies?

3. Can I simply modify the test firmware to write the desired frequency into the radio frequency register? Will that work? I am asking this since I do not have a spectrum analyzer at my disposal.

Best Regards,

MCM    

[ovrebekk]

Hi

It sounds odd that the radio_test example stops at 2405MHz. It should supports all channels from 2400-2480MHz. 

1. How does this limit occur?

In terms of other examples you can use the direct test mode example from the SDK:
\nRF5_SDK_17.0.0_9d13099\examples\dtm\direct_test_mode

The advantage of this example is that you can control the device under test from the Direct Test Mode application in nRF Connect, or you can control it from third party test equipment that supports the DTM standard. 

2. The SoftDevice controls the frequency directly through the NRF_RADIO->FREQUENCY register. 

3. As mentioned above this shouldn't be necessary, the example should support all frequencies in the 2400-2480MHz range. 

Best regards
Torbjørn