BLE Test Tx sweep

[Ramesh]

Hi,

As a part of FCC testing, I am trying use the following radio_tx_sweep_start(txpower,uiMode,channel_start,channel_end,delayms) with below parameters.

uint8_t txpower = RADIO_TXPOWER_TXPOWER_Pos4dBm;
uint8_t uiMode = RADIO_MODE_MODE_Ble_1Mbit;
uint8_t channel_start = 02;
uint8_t channel_end = 80;
uint8_t delayms=200;

 As per my understanding we need to see the only 40 Tx channels sweep in the Spectrum Analyzer,But i am seeing the 80 channels.

My Question:  Why it's not moving BLE mode?????

I am using BLE mode i.e. RADIO_MODE_MODE_Ble_1Mbit, but still i am seeing 80 channels instead of 40 channels. Can you please answer how to do BLE 40 channels sweep.

Regards,

Ramesh Javadi

[bjorn-spockeli]

HI Ramesh, 

the naming in the radio test example is a bit misleading as the channel is infact the offset from 2400MHz, i.e. 

Frequency = 2400MHz + channel

Hence, with channel_start = 02 and channel_end = 80 the Radio Test example will sweep the frequency between 2400MHz to 2480MHz. 

If you want the sweep to do 2MHz increments instead of 1MHz increments in the frequency, then you can modify the m_channel++ line to m_channel = m_channel +2 in TIMER0_IRQHandler in radio_test.c

void TIMER0_IRQHandler(void)
{
    uint8_t channel_end   = m_channel_end;
    uint8_t channel_start = m_channel_start;
    uint8_t mode          = m_mode;
    uint8_t txpower       = m_txpower;

    // COMPARE[0] handles channel sweep
    if (NRF_TIMER0->EVENTS_COMPARE[0])
    {
        NRF_TIMER0->EVENTS_COMPARE[0] = 0;
        if (m_sweep_tx)
        {
            radio_unmodulated_tx_carrier(txpower, mode, m_channel);
        }
        else if (m_sweep_rx)
        {
            radio_rx(mode, m_channel);
        }
        else
        {
           //Do nothing
        }

        m_channel = m_channel +2;
        if (m_channel > channel_end)
        {
            m_channel = channel_start;
        }
    }
    // Timer sequence for function
    // radio_modulated_tx_carrier_with_delay(...)
    if (NRF_TIMER0->EVENTS_COMPARE[1])
    {
        NRF_TIMER0->EVENTS_COMPARE[1] = 0;
        if (!m_sweep_tx || !m_sweep_rx)
            NRF_RADIO->TASKS_TXEN = 1;
    }
}

Best regards

Bjørn

[Ramesh]

Hi Bjorn,

Thanks for the info.

Regards,

Ramesh javadi

[bjorn-spockeli]

Happy to help