TX/RX question of Radio test of SDK 15.2

RE: TX/RX question of Radio test of SDK 15.2

Hsu — Wed, 20 May 2020 05:51:10 GMT

HI Minseo,

The picture copy from the equipment, not a software program.

The equipment company now name as "Keysight Technologies"

You can search "Keysight" for more information.

RE: TX/RX question of Radio test of SDK 15.2

Minseo — Wed, 20 May 2020 01:54:43 GMT

Hi,

Where did you download the program called Agilent Spectrum Analyzer?

RE: TX/RX question of Radio test of SDK 15.2

Håkon Alseth — Mon, 12 Nov 2018 09:12:35 GMT

Hi,

You can try to use "zero span" to see the power vs. time, where you should then see an approximate duty cycle of 50%.

Kind regards,

Håkon

RE: TX/RX question of Radio test of SDK 15.2

Hsu — Fri, 09 Nov 2018 14:20:23 GMT

Hi Håkon,

Thank for quick response.

If the duty cycle set to 50 % is too fast to be recognized in the spectrum, how do we set to make the spectrum can recognize?

Because we use below setting, but got below result.

----- setting -----

uart_cli:~$ start_channel 02
Start channel set to: 2.
uart_cli:~$ parameters_print
Parameters:
Data rate: RADIO_MODE_MODE_Ble_1Mbit
TX power: RADIO_TXPOWER_TXPOWER_Pos8dBm
Transmission pattern: TRANSMIT_PATTERN_RANDOM
Start Channel: 2
End Channel: 80
Time on each channel: 10 ms
Duty cycle: 50 percent
uart_cli:~$ start_tx_modulated_carrier

--------------------

====== result =========

====================

RE: TX/RX question of Radio test of SDK 15.2

Håkon Alseth — Fri, 09 Nov 2018 13:42:46 GMT

Hi,

[quote user="Hanyu"]2. For TX, we expect to see the modulated signal, but as follow below setting, we only see the continues signal, is it correct?[/quote]

In this mode, you shall see a modulated output, and looking at the screenshots from your spectrum analyzer, the output is modulated. The duty cycle is set to 50 %, which means that the program will transmit every 4 ms (one payload takes ~2 ms with 261 bytes length @1MBit). This might be too fast to be recognized in the spectrum. If you demodulate the data, or look at the input power vs. time, you should see a approximate 50% duty cycle of the RF signal.

[quote][/quote]

But what kind of environment setting we can use "TRANSMIT_PATTERN_RANDOM"?

This is normally used for compliance testing, as the bit stream should be randomized in most compliance testing programs.

Kind regards,

Håkon

RE: TX/RX question of Radio test of SDK 15.2

Hsu — Fri, 09 Nov 2018 12:39:27 GMT

Hi Håkon,

1. As changed the pattern to "TRANSMIT_PATTERN_11110000", we can get the data as below.

But what kind of environment setting we can use "TRANSMIT_PATTERN_RANDOM"?

2. For TX, we expect to see the modulated signal, but as follow below setting, we only see the continues signal, is it correct?

Thank you. Han

RE: TX/RX question of Radio test of SDK 15.2

Håkon Alseth — Fri, 09 Nov 2018 10:08:33 GMT

Hi,

Unfortunately, it is not possible to do a TX/RX communication test with 2 kits using the radio_test example.

The default transmission pattern will be to randomize the RF addresses, so even if they are on the same channel, no payload will be received.

A quick way to test would be to go into radio_test.c::radio_config() and in the case "TRANSMIT_PATTERN_RANDOM", hard-code the NRF_RADIO->PREFIX0 and NRF_RADIO->BASE0 register, then recompile and load the new hex file onto both kits.

The other two transmit patterns are not ideal for actual communication due to the toggling pattern, but you should still receive data even if you choose "TRANSMIT_PATTERN_11001100" or "TRANSMIT_PATTERN_11110000".

Kind regards,

Håkon