how to set RF modulation type?

RE: how to set RF modulation type?

roger.k — Tue, 23 Aug 2016 07:48:15 GMT

It's very helpful. Thank you very much for your help.

RE: how to set RF modulation type?

Einar Thorsrud — Tue, 23 Aug 2016 07:29:37 GMT

There is no specific "non-modulation" mode, only the 4 modes listed in my answer. Constant carrier is enabled by setting the CONSTCARRIER field of the TEST register, as you do.

RE: how to set RF modulation type?

roger.k — Tue, 23 Aug 2016 07:19:17 GMT

Thank you very much for your help. I already got my source code from "radio test" example source code. What i really want to know is "How can I make it non-modulation mode?" or "Which #define do I choose for non-modulation mode?". NRF_RADIO->MODE = ??? NRF_RADIO->TEST = ???

I need your help.

RE: how to set RF modulation type?

Einar Thorsrud — Tue, 23 Aug 2016 07:05:43 GMT

You can output a carrier wave. This is done for example in the radio test example in the SDK. This function is used to configure the radio for carrier output in the example:

void radio_tx_carrier(uint8_t txpower, uint8_t mode, uint8_t channel)
{
    radio_disable();
    NRF_RADIO->SHORTS     = RADIO_SHORTS_READY_START_Msk;
    NRF_RADIO->TXPOWER    = (txpower << RADIO_TXPOWER_TXPOWER_Pos);    
    NRF_RADIO->MODE       = (mode << RADIO_MODE_MODE_Pos);
    NRF_RADIO->FREQUENCY  = channel;
#ifdef NRF51
    NRF_RADIO->TEST       = (RADIO_TEST_CONST_CARRIER_Enabled << RADIO_TEST_CONST_CARRIER_Pos) \
                            | (RADIO_TEST_PLL_LOCK_Enabled << RADIO_TEST_PLL_LOCK_Pos);
#endif
    NRF_RADIO->TASKS_TXEN = 1;
}

RE: how to set RF modulation type?

roger.k — Tue, 23 Aug 2016 06:43:32 GMT

What if I don't want any Modulation, how can i do?

RE: how to set RF modulation type?

Einar Thorsrud — Tue, 23 Aug 2016 06:40:33 GMT

The radio only support GFSK modulation, and only the following four variants:

1 Mbit/s Nordic proprietary radio mode
2 Mbit/s Nordic proprietary radio mode
250 kbit/s Nordic proprietary radio mode (deprecated, but working)
1 Mbit/s Bluetooth Low Energy

The difference between the 1 Mbit proprietary and 1 Mbit BLE mode is mainly that the modulation index is different.