Espressif Systems ESP Faq page 8

4.1.44 How can I input the PIN code via mobile phone during ESP32' s Classic Bluetooth Pairing
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4.1.45 How much memory does ESP32 Bluetooth occupy?
4.1.46 When I use the "gattc_gatts_coex.c"example on ESP32 to test BLE multi-connection,
it can only connect to four devices even after I set the BLE Max connections in
menuconfig to five. What is the reason?
4.1.47 Does ESP32-C3 BLE support master and slave mode at the same time? What is the number
of connections in master mode and slave mode?
4.1.48 What is the maximum MTU Size of ESP32 Classic Bluetooth?
4.1.49 How can I resolve the frequently occurred ELxXX error (such as ELx200) when Wi-Fi and
Ble co-exit？
4.1.50 How does BLE capture packets?
4.1.51 When I use an ESP32 development board to test several versions of bluefi example under
ESP-IDF for networking, the following error kept printing. What is the reason?
4.1.52 When I use ESP32, can Light-sleep mode be enabled for Bluetooth and can Bluetooth be
kept connected in Light-sleep mode?
4.1.53 How can I modify the Bluetooth device name of ESP32?
4.1.54 What is the maximum supported broadcast length of BLE 5.0 broadcast after it is set to
legacy mode?
4.1.55 How can I set a BLE broadcast package as unconnectable package?
4.1.56 How can I send Bluetooth HCI commands directly to ESP32-WROOM-32D module
through the serial port?
4.1.57 Does ESP32 support transmitting audio stream using A2DP?
4.1.58 How many devices can be connected at the most as suggested by the White List of ESP32
Bluetooth LE?
4.1.59 Can ESP32 Bluetooth LE use PSRAM?
4.1.60 When using ESP32-C3 BLE Scan, can I set it to only scan the Long Range devices?
4.1.61 Is there a limit to the name length of ESP32 as a Bluetooth device?
4.1.62 How do I set the ESP32 BLE Scan to the permanent scan without generating a timeout?
4.1.63 How can I get RSSI of BLE devices through ESP32?
4.1.64 How can I increase the transmission distance of BLE5.0? How can I set BLE5.0 to long-
range mode?
4.1.65 I have changed the name of the Bluetooth device with esp_ble_gap_set_device_name() in
ESP32-C3. It works for Android devices and the customized device name can be shown.
However, it does not work on IOS devices. The device name is still the default Bluetooth
name. How can I make it work on Apple devices as well?
4.1.66 I want to use two ESP32 development boards to test the Bluetooth connection. How
can I set the specified key to automatically connect them with gatt_security_client and
gatt_security_server examples?
4.1.67 After setting
gatt_security_client to ESP_IO_CAP_OUT mode, I deliberately set the wrong passkey.
However, the two development boards can still be connected. What is the reason?
4.1.68 Does ESP32-C3/ESP32-C6/ESP32-S3 support Bluetooth AOA/AOD?
4.1.69 What is the maximum length of data in a BLE advertising packet supported by ESP32-C3
with the BLE5.0 feature?
4.1.70 Does ESP32 have any API to check whether BLE advertising has started or stopped?
4.2 Ethernet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
4.2.1 When building an example on ESP32 Ethernet development board, an error occurred as
"emac: Reset EMAC Timeout". What could be the reasons?
4.2.2 When ESP32 connected to LAN8720 externally, with GPIO0 providing CLK, the initial-
ization of Ethernet example failed. How to resolve such issue?
4.2.3 When using the Ethernet example in ESP-IDF, an error occurred as "Timed out waiting
for PHY register 0x3 to have value 0xc0f0 (mask 0xfff0). Current value 0xffff". How to
resolve such issue?
4.2.4 When using ESP-IDF v4.1, how to set the static IP for ESP32 Ethernet?
4.2.5 Is there any impact on Ethernet functionality if replacing the module of ESP32-Ethernet-
Kit with ESP32-WROOM-32D?
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gatt_security_server
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to ESP_IO_CAP_OUT mode
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and setting
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