Questions about Nordic Distance Measurement library sample

Question

1. The code uses a value 0xFF55AA5A to identify the adv packet as the one that supports distance measurement. Is this value checked by lower layers? 
 If not - why not just use 1 bit ? 
 2. The advertising interval in the sample is set to BT_GAP_ADV_FAST_INT_MIN_1 ( 30 ms ) 
 Have slower intervals been tested ? My concern is the device battery life 
 3. My application uses mesh and its scanner ( registers a scanner callback ) 
 Have the app been tested with mesh? 
 Thanks

Amanda Hsieh · Answer

Hi, 
 2): You should be able to reduce the time, but that means that it takes longer until the ranging starts. 
 3 ): We are working on this. 
 I will be back with the answer for Q1. 
 Regards, Amanda

Amanda Hsieh · Answer

Hi, 
 From the team: 
 1. The code uses a value 0xFF55AA5A to identify the adv packet as the one that supports distance measurement. Is this value checked by lower layers? 
 If not - why not just use 1 bit ? 
 This value is defined in the sample code and is used be the bt_scan module to identify device that support distance measurement. This value is not used by the subsys/dm module. 
 I thing the value could be shorter, such as 1 byte. The length of data passed to bt_scan is given in bytes. We used 4 byte value to avoid situations where other device that also advertise `MANUFACTURER_DATA` (but not support DM) have the same byte sequence after the company_cod field. 
 As for mesh, it will be nice if you wait a bit. If you want to try, you can use model messages to achieve synchronization as shown here: https://github.com/omkar3141/sdk-nrf/commit/53fb0582da728e3b35e125bfc971c1cb8d5962d8 
 To evaluate, flash the light and light_switch on two boards, and press SW0 on the light_switch sample. 
 -Amanda H.

Questions about Nordic Distance Measurement library sample

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