STS error on DWM3220 message exchange

Wireless Connectivity Ultra-Wideband
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1

Hello,

I’m working on an RTLS project and I have a custom DWM3220 based device with two antennas acting as an anchor and a DWM3000 based device acting as a tag. I’m quite new to UWB and I used the examples from DW3XXX_API to work with the devices. I want to obtain PDOA values on the anchor side using examples 01h and 02h but so far I’m not able to get STS working.

This is my configuration:
{
.channel = DWM_CHANNEL_5,
.tx_preamble_length = DWM_PREAMBLE_LENGTH_128,
.rx_pac = DWM_PAC_8,
.tx_preamble_code = DEFAULT_PREAMBLE_CODE,
.rx_preamble_code = DEFAULT_PREAMBLE_CODE,
.sfd_type = DWM_SFD_TYPE_DW_8,
.data_rate = DWM_DATA_RATE_6M8,
.phr_mode = DWM_PHR_MODE_STANDARD,
.phr_rate = DWM_PHR_RATE_STANDARD,
.sfd_timeout = (129 + 8 - 8),
.sts_mode = (DWM_STS_MODE_1 | DWM_STS_MODE_SUPER_DETERMINISTIC),
.sts_length = DWM_STS_LENGTH_256,
.pdoa_mode = DWM_PDOA_MODE_3,
}

Function dwt_readstsquality() always returns -230 and STS quality is 0.
I tried setting STS key and iv as the default values before each tx/rx and it did not work.

Is there something wrong with the configuration or what could be the issue? Thank you!

2

Hello. The issue was with my code. PDoA values are coming now.

3

Hi, i think to have the same issue. Do you obtain correct values for the angles?

4

Hello, yes, I obtain correct values, with some variations of course. In the code that I was using there was a bug with the defines so I thought that STS was enabled but in fact it was not.

5

When i calculate the angle i obtain strange values: seems to be doubled.
Do you occure in the same problem? Can i ask you wich formula did you use to convert the pdoa values into deg angles?
Mine is: deg_value=pdoa_value180/(2048pi)
Thx and have a nice day

6

Hi,
Based on
https://www.researchgate.net/profile/Igor-Dotlic/publication/322408155_Angle_of_arrival_estimation_using_decawave_DW1000_integrated_circuits/links/5a5cd5430f7e9b4f783965fd/Angle-of-arrival-estimation-using-decawave-DW1000-integrated-circuits.pdf
the formula for obtaining the angle of arrival from the PDoA value is:
image
where alpha is your PDoA, lamdba is the carrier wavelentgh and d is your antenna pitch. The result will be in radians and to convert in degrees you have to multiply by 180 and then divide by Pi.