About simple PDOA sample

Wireless Connectivity Ultra-Wideband
1

HI,qorvo team

1
1856×1511 139 KB

ex_01h_simple_tx_pdoa
ex_02h_simple_rx_pdoa

static void rx_ok_cb(const dwt_cb_data_t * cb_data)
{
int16_t cpqual;
int stsq = dwt_readstsquality(&cpqual);
NRF_LOG_INFO(“rx_ok_cb:stsq=%d”, stsq);
if(stsq >= 0)
{
pdoa_val = dwt_readpdoa();
NRF_LOG_INFO(“rx_ok_cb:pdoa_val=%d”, pdoa_val);
*float pdoa_deg = ((float) pdoa_val/(1<<11))180/3.1415926;
NRF_LOG_INFO(“rx_ok_cb:pdoa_deg=” NRF_LOG_FLOAT_MARKER, NRF_LOG_FLOAT(pdoa_deg));
}
dwt_rxenable(DWT_START_RX_IMMEDIATE);
}

I used Murata’s EVB directly against DWM3000, but the result is the following data, where am I wrong???

app: rx_ok_cb:pdoa_val= -870
app: rx_ok_cb:pdoa_deg= -24.33
app: rx_ok_cb:stsq=22
app: rx_ok_cb:pdoa_val= -709
app: rx_ok_cb:pdoa_deg= -19.83
app: rx_ok_cb:stsq=22
app: rx_ok_cb:pdoa_val= -571
app: rx_ok_cb:pdoa_deg= -15.97
app: rx_ok_cb:stsq=22
app: rx_ok_cb:pdoa_val= -814
app: rx_ok_cb:pdoa_deg= -22.77
app: rx_ok_cb:stsq=21
app: rx_ok_cb:pdoa_val= -443
app: rx_ok_cb:pdoa_deg= -12.39
app: rx_ok_cb:stsq=22
app: rx_ok_cb:pdoa_val= -633
app: rx_ok_cb:pdoa_deg= -17.70

kk
thanks

6

What are you suggesting is wrong with the data that you are receiving?

7

It looks like you are using the DecaWave DW3000 chip and are trying to read the phase of arrival (PoA) of a received signal using the dwt_readpdoa function. The PoA value is returned as a 16-bit signed integer, and it is expressed in units of 1/512 of a chip.

In your code, you are converting the PoA value to degrees by dividing it by (1<<11), which is the same as dividing by 2048. This is not the correct conversion factor, as 1 degree is not equal to 2048/512 = 4 chips.

To convert the PoA value to degrees, you can use the following formula:
float pdoa_deg = (float)pdoa_val * 180 / (3.1415926 * 512);

This formula takes into account the fact that there are 2π radians in a full circle (360 degrees), and that the PoA value is expressed in units of 1/512 of a chip.

I hope this helps! Let me know if you have any further questions.