Bluetooth: how an active scanner can retrieve scan response data linked to a certain listened MAC address?

[ThLOCP]

Hi
I am struggling with Bluetooth API :

I am developing an active scanner that listens to a certain device complete name and it must continuously retrieve the corresponding scan response data of this device advertivements.

I am acostumized to work with Nordic nRF52 chips and nRF SDK where I could do it easily with the event BLE_GAP_EVT_ADV_REPORT and the p_gap_evt->params.adv_report in which both advertised data and scan response data are present. Using Zephyr API I do not find the way to do the same thing.

I could achieve in retrieving scan response data using a callback data_cb() but I do not known to which MAC address these data are link to?

Is anyone could help on that?

Thanks in advance,

Best regards,
Thierry

[Zebsi235]

Hello, sadly I don't have an answer for you but right now im kinda struggeling with the same Problem. Can you tell me how you even got the scan response data. I am able to read the advertising data, but I cant find a way to get the scan response even if I put the scan in active mode. I also did't really find something in the docu of Zephyr.

Thank you for your help!!

[ThLOCP]

Hi Zerberstian, Find attached what I use. No support but it works for me with zephyr 2.4.0. Hope this will help you. Regards, Thierry De : Zerberstian ***@***.*** Envoyé : mercredi 23 mars 2022 16:32 À : zephyrproject-rtos/zephyr Cc : LAMOTTE Thierry; Author Objet : Re: [zephyrproject-rtos/zephyr] Bluetooth: how an active scanner can retrieve scan response data linked to a certain listened MAC address? (Discussion #30383) Hello, sadly I don't have an answer for you but right now im kinda struggeling with the same Problem. Can you tell me how you even got the scan response data. I am able to read the advertising data, but I cant find a way to get the scan response even if I put the scan in active mode. I also did't really find something in the docu of Zephyr. Thank you for your help!! — Reply to this email directly, view it on GitHub<#30383 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AHBSE3UVEEV7WLSIVQDAFX3VBM2OBANCNFSM4UKIGWMA>. You are receiving this because you authored the thread.Message ID: ***@***.***> // ---------------------------------------------------------------------------- char *ble_get_scan_response_data_as_string(uint8_t device_state, uint8_t device_status) { char* str_pt; if (ble_is_connected()==true) { target_infos.scan_response_data[1]=(uint8_t)device_state; target_infos.scan_response_data[2]=(uint8_t)device_status; str_pt = conv2str((uint8_t*)&target_infos.scan_response_data[0], target_infos.scan_response_data_len); } else { char tmpscanresp[25]={0x41, device_state, device_status}; // short one str_pt = conv2str((uint8_t*)&tmpscanresp[0], 3); } return (char*)DEVICE_SCAN_RESP_DATA_IN_ASCII_BUFFER; } // ---------------------------------------------------------------------------- int ble_get_rssi_as_int(void) { return target_infos.rssi; } // ---------------------------------------------------------------------------- char *conv2str(uint8_t *pt, uint8_t len) { char tempstr[ADV_MAXSIZE]=""; memset(DEVICE_SCAN_RESP_DATA_IN_ASCII_BUFFER, 0, sizeof(DEVICE_SCAN_RESP_DATA_IN_ASCII_BUFFER)); for (int i=0;i<len;i++, pt++) { snprintk((char*)tempstr, (size_t)ADV_MAXSIZE, "%02X", (uint8_t)*pt); strcat((char*)DEVICE_SCAN_RESP_DATA_IN_ASCII_BUFFER,(char*)tempstr); } return (char*)DEVICE_SCAN_RESP_DATA_IN_ASCII_BUFFER; } // ---------------------------------------------------------------------------- static uint8_t* get_complete_name(uint8_t *buf_pt) { // parse the adv (LEN, TYPE, VALUE) fields for (uint8_t len=*buf_pt; len<ADV_MAXSIZE; ) { len = *buf_pt; if (*(buf_pt+1)==BT_DATA_NAME_COMPLETE) // looking for type complet name only { return (uint8_t*)(buf_pt+2); // point to start address of the complete name } // jump to the next adv (LEN, TYPE, VALUE) field buf_pt+=len+1; } return (uint8_t*)0; } // ---------------------------------------------------------------------------- static void device_found(const bt_addr_le_t *addr, int8_t rssi, uint8_t type, struct net_buf_simple *ad) { char addr_str[BT_ADDR_LE_STR_LEN]; uint8_t zero_val[6]={0,0,0,0,0,0}; if ((default_conn) || (strcmp(BLE_TARGET_NAME,"")==0)) { return; } // only close devices if (rssi < -70) { return; } /* We're only interested in connectable events */ if ( type != BT_GAP_ADV_TYPE_ADV_IND && type != BT_GAP_ADV_TYPE_ADV_DIRECT_IND && type != BT_GAP_ADV_TYPE_SCAN_RSP) { return; } if (type == BT_GAP_ADV_TYPE_SCAN_RSP) { if ( (memcmp((void*)target_infos.mac_addr.a.val, zero_val, sizeof(bt_addr_t))!=0) // i.e. has been init at least once && (memcmp((void*)&target_infos.mac_addr, addr, sizeof(bt_addr_le_t))==0)// Scan Resp correspond to our target complete name ) { bt_addr_le_to_str(addr, addr_str, sizeof(addr_str)); // Keep a copy of the scan response data memset((void*)target_infos.scan_response_data, 0, sizeof(target_infos.scan_response_data)); if (ad->len<=sizeof(target_infos.scan_response_data)) { char* str_pt; memcpy((void*)&target_infos.scan_response_data[0], (void*)&ad->data[6], ad->len-6); target_infos.scan_response_data_len = ad->len-6; str_pt = conv2str((uint8_t*)&target_infos.scan_response_data[0], target_infos.scan_response_data_len); /* ... */ } ble_request_delayed_connection(false); } } else { uint8_t *ptto_crt_complete_name = get_complete_name((uint8_t*)&ad->data[0]); if ( (ptto_crt_complete_name!=(void*)0) && (strstr((void*)ptto_crt_complete_name, (void*)BLE_TARGET_NAME )!=NULL) ) { bt_addr_le_to_str(addr, addr_str, sizeof(addr_str)); /* ... */ // Keep a copy of the MAC address to be used & checked by the Scan Response use case memcpy((void*)&target_infos.mac_addr, addr, sizeof(bt_addr_le_t)); target_infos.rssi=rssi; } } } // ---------------------------------------------------------------------------- static void start_scan(bool reinit_dbg_retry_limit) { int err; memset((void*)&target_infos,0,sizeof(target_infos_type)); //bt_le_scan_cb_register(&cb); /* We require active scan to retrieve scan response data*/ bt_le_scan_stop(); err = bt_le_scan_start(BT_LE_SCAN_ACTIVE, device_found); if (err) { printk("Scanning failed to start (err %d)\n", err); return; } printk("Scanning successfully started\n"); }