Peers added to the scanning whitelist

Question

Hi, 
 
 I am looking at and testing the ble_app_hrs_c_pca10040_s132 example. 
 When the whitelist ist set up with the "whitelist request" we execute the following two lines: 
 peer_list_get(peers, &peer_cnt);
ret = pm_whitelist_set(peers, peer_cnt); 
 However, the function "peer_list_get" does not return the peers in the order of their rank according to my observations and also the documentation page of pm_next_peer_id_get which is called by "peer_list_get": The order in which peer IDs are returned should be considered unpredictable 
 So this means we just add the first 8 peers in the peer list which probably just correspond to the first 8 peers ever connected. 
 I think the example should use something like: 
 pm_peer_data_load(p_all_peer_ids[all_peers_cnt-1], PM_PEER_DATA_ID_PEER_RANK, &rank, &rankLenght); 
 to get the peer ranks and then order the peers accordingly before adding them to the whitelist. 
 
 Are those observations and conclusions correct? 
 Thank you for your response.

Erikk · Accepted Answer

The problem with the function pm_peer_ranks_get() is that it only returns the highest and the lowest ranked peers. If you want to put the last connected 8 peers into the whitelist this does not help. All the nordic examples using a whitelist are actually just putting the first 8 connected peers into the whitelist and NOT the 8 peers the device has been connected to last. I would suggest to use something like this in all the nordic examples in the next SDK. Where can I propose this? + /*************** ranks **************/ + UINT32_T ranks[MAX_PEERS_CHECKED]; + memset(ranks, 0xFF, sizeof(ranks)); + /*************** ranks **************/ // get all the peer IDs from peerlist pm_peer_id_t current_peer_id = pm_next_peer_id_get(PM_PEER_ID_INVALID); while (current_peer_id != PM_PEER_ID_INVALID) { - p_all_peer_ids[all_peers_cnt++] = current_peer_id; + p_all_peer_ids[all_peers_cnt] = current_peer_id; + + /******************************** printing MAC BEGIN *********************************************/ + NRF_LOG_DEBUG(" peer id in p_all_peer_ids = %u",current_peer_id); + pm_peer_data_app_data_load(p_all_peer_ids[all_peers_cnt], &sPeerAppData, &UINT32_PeerDataSize); + NRF_LOG_DEBUG(" MAC in p_all_peer_ids = %x %x %x %x",sPeerAppData.vUINT8_DeviceAddress[0], sPeerAppData.vUINT8_DeviceAddress[1], sPeerAppData.vUINT8_DeviceAddress[2], sPeerAppData.vUINT8_DeviceAddress[3]); + /******************************** printing MAC BEGIN *********************************************/ + + /******************************** Peer ranks BEGIN *********************************************/ + UINT32_T rank; + UINT16_T rankLenght = sizeof(rank); + ret = pm_peer_data_load(p_all_peer_ids[all_peers_cnt], PM_PEER_DATA_ID_PEER_RANK, &rank, &rankLenght); + ranks[all_peers_cnt] = rank; + NRF_LOG_DEBUG(" return code of pm_peer_data_load %u",ret); + // we could also use pm_peer_data_store/delete with the pm_peer_data_id PM_PEER_DATA_ID_PEER_RANK + NRF_LOG_DEBUG(" rank in p_all_peer_ids %u",rank); + NRF_LOG_DEBUG("---------------------"); + /******************************** Peer ranks END ***********************************************/ + current_peer_id = pm_next_peer_id_get(current_peer_id); + all_peers_cnt++; + } + + /******************************** order the peers by rank BEGIN ******************************/ + // we have two arrays: ranks and p_all_peer_ids. we want to order p_all_peer_ids according the the ranks + typedef struct + { + int index_from_A; + int value_from_B; + } index_value_wrapper; + + index_value_wrapper index_wrapper_array[all_peers_cnt]; + + for (int i=0; i < all_peers_cnt ; i++) + { + index_wrapper_array[i].index_from_A = p_all_peer_ids[i]; + index_wrapper_array[i].value_from_B = ranks[p_all_peer_ids[i]]; } + + int comparator (const void* lhs, const void* rhs) + { + // TODO switch left and right to get the decreasing order + int l = ((index_value_wrapper *)lhs)->value_from_B; + int r = ((index_value_wrapper *)rhs)->value_from_B; + return (r - l); + + //return (lhs.value_from_B - rhs->value_from_B); + } + + // sort the struct with the peer ids according to ranks + qsort(index_wrapper_array, all_peers_cnt, sizeof(index_value_wrapper), comparator); + + // extract the sorted peers and save in p_all_peer_ids + for(int extract_i=0; extract_i < all_peers_cnt; extract_i++){ + p_all_peer_ids[extract_i] = index_wrapper_array[extract_i].index_from_A; + NRF_LOG_DEBUG(" peer id in p_all_peer_ids AFTER SORTING = %u",p_all_peer_ids[extract_i]); + } + + + /******************************** order the peers by rank END ********************************/

Peers added to the scanning whitelist

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