Espressif Systems ESP User Manual

Chapter 4. Software framework
4.1.60 When using ESP32-C3 BLE Scan, can I set it to only scan the Long Range devices?
• Yes, you can make tests based on esp-idf/examples/bluetooth/bluedroid/ble_50/ble50_security_client.
By changing the con󰝘guration .cfg_mask = ESP_BLE_GAP_EXT_SCAN_CFG_UNCODE_MASK
| ESP_BLE_GAP_EXT_SCAN_CFG_CODE_MASK
in
ext_scan_params to .cfg_mask =
ESP_BLE_GAP_EXT_SCAN_CFG_CODE_MASK, you can scan the broadcast packets whose primary
PHY type is LE CODED PHY.
4.1.61 Is there a limit to the name length of ESP32 as a Bluetooth device?
• The names should be no longer than 248 bytes. However, in practice, the name length is also limited by
the length of Bluetooth advertising packets. For the description of con󰝘gurations, please refer to CON-
FIG_BT_MAX_DEVICE_NAME_LEN.
4.1.62 How do I set the ESP32 BLE Scan to the permanent scan without generating a
timeout?
• You can realize this by setting“duration”to 0 before using the esp_ble_gap_start_scanning() function to start
BLE Scan.
4.1.63 How can I get RSSI of BLE devices through ESP32?
• You can use the esp_ble_gap_read_rssi() function to get RSSI of connected BLE devices.
• If you want to get RSSI of all scanned BLE devices around, please use the ble_scan_result_evt_param structure
in the ESP_GAP_BLE_SCAN_RESULT_EVT event to enable the printing of RSSI.
4.1.64 How can I increase the transmission distance of BLE5.0? How can I set BLE5.0
to long-range mode?
• In practice, the transmission distance of BLE5.0 is about 200 m. It is recommended to refer to the actual test
distance. ESP32-S3 supports the features of BLE5.0, and supports long-range communication through Coded
PHY (125 Kbps and 500 Kbps) and broadcast extension.
• You can realize long-range communication by using 125 Kbps Coded PHY and increasing the transmit power
(tx_power). Refer to the following settings:
esp_ble_gap_ext_adv_params_t ext_adv_params_coded = {
.type = ESP_BLE_GAP_SET_EXT_ADV_PROP_SCANNABLE,
.interval_min = 0x50,
.interval_max = 0x50,
.channel_map = ADV_CHNL_ALL,
.filter_policy = ADV_FILTER_ALLOW_SCAN_ANY_CON_ANY,
.primary_phy = ESP_BLE_GAP_PHY_CODED,
.max_skip = 0,
.secondary_phy = ESP_BLE_GAP_PHY_CODED,
.sid = 0,
.scan_req_notif = false,
.own_addr_type = BLE_ADDR_TYPE_RANDOM,
.tx_power = 18,
};
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Espressif Systems ESP Specifications

General

Brand	Espressif Systems
Model	ESP
Category	Motherboard
Language	English