Need to configure device for EMC certification

[John Waters]

Hello,

We buy nRF52832 chips and use them integrated on our own PCBs.

Our devices are small BLE devices to which your phone, computer, anything can connect to.

They are BLE peripheral.

In order to pass EMC certifications (FCC, CE...) we are asked to make our device operate on different channel (frequencies).

How can this be done? A little search brought me to this topic:

https://devzone.nordicsemi.com/f/nordic-q-a/25281/changing-the-default-channel-map-with-sd_ble_opt_set

Where it says:

Only the central is allowed to request a change in the channel map.

Does that mean only a computer/phone can ask the BLE device to change its channel? I am a bit confused.

Thanks for your help,

[ketiljo]

The best is to use the radio test example to setup the radio for test: https://infocenter.nordicsemi.com/topic/sdk_nrf5_v17.1.0/nrf_radio_test_example.html or for NCS https://developer.nordicsemi.com/nRF_Connect_SDK/doc/1.9.1/nrf/samples/peripheral/radio_test/README.html

You usually need to setup a modulated carrier at channel 2402, 2440 and 2480 MHz, with 100% duty cycle and the datarate you are using, 2 Mbps usually. And RX on the same three channels. 

[John Waters]

Thank you. I do think it is awesome Nordic provides this kind of tool...

Unfortunately, we don't have a wired access to our product. We can only discuss with our product via Bluetooth, or we could hardcode things in the firmware. Also, we need the softdevice.

What is the easiest way to do this?

[ketiljo]

The easiest is to retrofit the UART wires to your product, just for the testing. You can also modify the radio test example to cycle through the modes with the press of a button if you have that.

You can't do this easily over Bluetooth as you need to disable the softdevice and take control over the radio. EMC testing isn't done with the Bluetooth protocol running.