LAUNCHXL-CC2640R2: The AOA test result with CC2640R2 and BOOSTXL-AOA

gu jianhua

Dear,

I just test the AOA angle by using BOOSTXL-AOA board . The demo path is in simplelink_cc2640r2_sdk_2_20_00_49\examples\rtos\CC2640R2_LAUNCHXL\blestack\aoa_receiver .

the angle error range 0 to 20 degree almost. How can I i mprove it ? TKS!

over 6 years ago

0 Christin Lee over 6 years ago

TI__Guru 56215 points

Hi,

The environment which you perform the measurement matters a lot, if you are in an open space with no metal around you, then you should see better result than this.

The result can be affected by multi-path reflection which creates a false angle of arrival.
The best way to use this demo is to
1. test it in the well controlled environment(antenna chamber) and analyzing the I/Q data.
2. Design your own filter (the current one in the BLE STACK is only moving average). You can add filtering base on standard deviation or even use the rssi value to decide to trust the data or not.
3. Once you are done with your own filter, then you can bring it to outdoor testing and check how good your filter is.

Our project is an example of how to use I/Q data to calculate the angle, it's not an end product and the magic will be developed by end user to make it perfect.

For more information please take a look at our user's guide Localization Toolbox section, user's guide can be found here:

http://dev.ti.com/tirex/#/?link=Software%2FSimpleLink%20CC2640R2%20SDK%2FDocuments%2FBLE-Stack%2FBLE-Stack%20User's%20Guide

0 gu jianhua over 6 years ago in reply to Christin Lee

Prodigy 30 points

Thanks for your suggestion !

Could you tell me the best angle err in your test environment ?

And i still have another question:

The compensation values for antenna array2 described in path' http://dev.ti.com/tirex/content/simplelink_cc2640r2_sdk_2_20_00_49/docs/blestack/ble_user_guide/html/localization/index.html#id6 '

AoA_AntennaPair pair_A2[] =
{
    {/* v12 */
        .a = 0,
        .b = 1,
        .sign = -1,
        .offset = -55,
        .gain = 0.80,
    },
    {/* v23 */
        .a = 1,
        .b = 2,
        .sign = -1,
        .offset = -45,
        .gain = 0.90,
    },
    {/* v13 */
        .a = 0,
        .b = 2,
        .sign = -1,
        .offset = -85,
        .gain = 0.40,
    },
};

The values are not  the same  with  the ant_array2_config_boostxl_rev1v1  in the simplelink_cc2640r2_sdk_2_20_00_49\examples\rtos\CC2640R2_LAUNCHXL\blestack\aoa_receiver\src\app.
how can i select the right values for my board?

0 Christin Lee over 6 years ago in reply to gu jianhua

TI__Guru 56215 points

Hi,

Angle measurement accuracy when averaged over 3 packets at 3 different frequencies using the AoA boosterpack is +/- 4 degrees. The environment is antenna chamber.

Those values are not important as they are derived based on data collected from antenna chamber. As the user's guide started, the offset is a value we added to make sure known angle 0 degree will be 0 degree when calculated from I/Q data. Then the gain is the slope.

With a customized board, those values will definitely have to be changed. But if you really want to start with something out of box, then take the values from software.

0 gu jianhua over 6 years ago in reply to Christin Lee

Prodigy 30 points

I got it , tks !

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LAUNCHXL-CC2640R2: The AOA test result with CC2640R2 and BOOSTXL-AOA