When compiling the code including the BluetoothSerial.h file, it prompts: undefined reference

[winseven2018]

Board

ESP32C3

Device Description

ESP32C3kit

Hardware Configuration

An I2C Device

Version

v2.0.2

IDE Name

Arduino

Operating System

Windows10

Flash frequency

80

PSRAM enabled

yes

Upload speed

115200

Description

I found that when compiling the code including the BluetoothSerial.h file, the console reported a lot of undefined references

Sketch

#include <BluetoothSerial.h>

#if !defined(CONFIG_BT_ENABLED) || !defined(CONFIG_BLUEDROID_ENABLED)
#error Bluetooth is not enabled! Please run `make menuconfig` to and enable it
#endif

BluetoothSerial SerialBT;


#define BT_DISCOVER_TIME	10000


static bool btScanAsync = true;
static bool btScanSync = true;


void btAdvertisedDeviceFound(BTAdvertisedDevice* pDevice) {
	Serial.printf("Found a device asynchronously: %s\n", pDevice->toString().c_str());
}

void setup() {
  Serial.begin(115200);
  SerialBT.begin("ESP32test"); //Bluetooth device name
  Serial.println("The device started, now you can pair it with bluetooth!");


  if (btScanAsync) {
    Serial.print("Starting discoverAsync...");
    if (SerialBT.discoverAsync(btAdvertisedDeviceFound)) {
      Serial.println("Findings will be reported in \"btAdvertisedDeviceFound\"");
      delay(10000);
      Serial.print("Stopping discoverAsync... ");
      SerialBT.discoverAsyncStop();
      Serial.println("stopped");
    } else {
      Serial.println("Error on discoverAsync f.e. not workin after a \"connect\"");
    }
  }
  
  if (btScanSync) {
    Serial.println("Starting discover...");
    BTScanResults *pResults = SerialBT.discover(BT_DISCOVER_TIME);
    if (pResults)
      pResults->dump(&Serial);
    else
      Serial.println("Error on BT Scan, no result!");
  }
}

void loop() {
  delay(100);
}

Debug Message

d:/tools/arduino/hardware/espressif/arduino-esp32/tools/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/8.4.0/../../../../riscv32-esp-elf/bin/ld.exe: libraries\BluetoothSerial\BluetoothSerial.cpp.o: in function `.L0 ':
D:\Tools\Arduino\hardware\espressif\arduino-esp32\libraries\BluetoothSerial\src/BluetoothSerial.cpp:651: undefined reference to `esp_spp_disconnect'
d:/tools/arduino/hardware/espressif/arduino-esp32/tools/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/8.4.0/../../../../riscv32-esp-elf/bin/ld.exe: libraries\BluetoothSerial\BluetoothSerial.cpp.o: in function `_stop_bt':
D:\Tools\Arduino\hardware\espressif\arduino-esp32\libraries\BluetoothSerial\src/BluetoothSerial.cpp:652: undefined reference to `esp_spp_deinit'
d:/tools/arduino/hardware/espressif/arduino-esp32/tools/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/8.4.0/../../../../riscv32-esp-elf/bin/ld.exe: libraries\BluetoothSerial\BluetoothSerial.cpp.o: in function `.LVL35':
D:\Tools\Arduino\hardware\espressif\arduino-esp32\libraries\BluetoothSerial\src/BluetoothSerial.cpp:253: undefined reference to `esp_bt_gap_set_scan_mode'
d:/tools/arduino/hardware/espressif/arduino-esp32/tools/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/8.4.0/../../../../riscv32-esp-elf/bin/ld.exe: libraries\BluetoothSerial\BluetoothSerial.cpp.o: in function `esp_spp_cb':
D:\Tools\Arduino\hardware\espressif\arduino-esp32\libraries\BluetoothSerial\src/BluetoothSerial.cpp:259: undefined reference to `esp_spp_start_srv'
d:/tools/arduino/hardware/espressif/arduino-esp32/tools/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/8.4.0/../../../../riscv32-esp-elf/bin/ld.exe: D:\Tools\Arduino\hardware\espressif\arduino-esp32\libraries\BluetoothSerial\src/BluetoothSerial.cpp:271: undefined reference to `esp_spp_disconnect'
d:/tools/arduino/hardware/espressif/arduino-esp32/tools/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/8.4.0/../../../../riscv32-esp-elf/bin/ld.exe: D:\Tools\Arduino\hardware\espressif\arduino-esp32\libraries\BluetoothSerial\src/BluetoothSerial.cpp:339: undefined reference to `esp_spp_connect'
d:/tools/arduino/hardware/espressif/arduino-esp32/tools/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/8.4.0/../../../../riscv32-esp-elf/bin/ld.exe: D:\Tools\Arduino\hardware\espressif\arduino-esp32\libraries\BluetoothSerial\src/BluetoothSerial.cpp:350: undefined reference to `esp_spp_disconnect'
d:/tools/arduino/hardware/espressif/arduino-esp32/tools/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/8.4.0/../../../../riscv32-esp-elf/bin/ld.exe: libraries\BluetoothSerial\BluetoothSerial.cpp.o: in function `.L0 ':
D:\Tools\Arduino\hardware\espressif\arduino-esp32\libraries\BluetoothSerial\src/BluetoothSerial.cpp:177: undefined reference to `esp_spp_write'
d:/tools/arduino/hardware/espressif/arduino-esp32/tools/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/8.4.0/../../../../riscv32-esp-elf/bin/ld.exe: D:\Tools\Arduino\hardware\espressif\arduino-esp32\libraries\BluetoothSerial\src/BluetoothSerial.cpp:141: undefined reference to `esp_bt_gap_set_pin'
d:/tools/arduino/hardware/espressif/arduino-esp32/tools/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/8.4.0/../../../../riscv32-esp-elf/bin/ld.exe: D:\Tools\Arduino\hardware\espressif\arduino-esp32\libraries\BluetoothSerial\src/BluetoothSerial.cpp:586: undefined reference to `esp_bt_gap_register_callback'
d:/tools/arduino/hardware/espressif/arduino-esp32/tools/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/8.4.0/../../../../riscv32-esp-elf/bin/ld.exe: libraries\BluetoothSerial\BluetoothSerial.cpp.o: in function `_init_bt':
D:\Tools\Arduino\hardware\espressif\arduino-esp32\libraries\BluetoothSerial\src/BluetoothSerial.cpp:595: undefined reference to `esp_spp_register_callback'
d:/tools/arduino/hardware/espressif/arduino-esp32/tools/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/8.4.0/../../../../riscv32-esp-elf/bin/ld.exe: D:\Tools\Arduino\hardware\espressif\arduino-esp32\libraries\BluetoothSerial\src/BluetoothSerial.cpp:603: undefined reference to `esp_spp_init'
d:/tools/arduino/hardware/espressif/arduino-esp32/tools/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/8.4.0/../../../../riscv32-esp-elf/bin/ld.exe: D:\Tools\Arduino\hardware\espressif\arduino-esp32\libraries\BluetoothSerial\src/BluetoothSerial.cpp:623: undefined reference to `esp_bt_gap_set_security_param'
d:/tools/arduino/hardware/espressif/arduino-esp32/tools/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/8.4.0/../../../../riscv32-esp-elf/bin/ld.exe: D:\Tools\Arduino\hardware\espressif\arduino-esp32\libraries\BluetoothSerial\src/BluetoothSerial.cpp:626: undefined reference to `esp_bt_gap_set_cod'
d:/tools/arduino/hardware/espressif/arduino-esp32/tools/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/8.4.0/../../../../riscv32-esp-elf/bin/ld.exe: libraries\BluetoothSerial\BluetoothSerial.cpp.o: in function `BluetoothSerial::disconnect()':
D:\Tools\Arduino\hardware\espressif\arduino-esp32\libraries\BluetoothSerial\src/BluetoothSerial.cpp:594: undefined reference to `esp_spp_disconnect'
d:/tools/arduino/hardware/espressif/arduino-esp32/tools/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/8.4.0/../../../../riscv32-esp-elf/bin/ld.exe: libraries\BluetoothSerial\BluetoothSerial.cpp.o: in function `BluetoothSerial::discover(int)':
D:\Tools\Arduino\hardware\espressif\arduino-esp32\libraries\BluetoothSerial\src/BluetoothSerial.cpp:953: undefined reference to `esp_bt_gap_set_scan_mode'
d:/tools/arduino/hardware/espressif/arduino-esp32/tools/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/8.4.0/../../../../riscv32-esp-elf/bin/ld.exe: D:\Tools\Arduino\hardware\espressif\arduino-esp32\libraries\BluetoothSerial\src/BluetoothSerial.cpp:956: undefined reference to `esp_bt_gap_start_discovery'
d:/tools/arduino/hardware/espressif/arduino-esp32/tools/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/8.4.0/../../../../riscv32-esp-elf/bin/ld.exe: D:\Tools\Arduino\hardware\espressif\arduino-esp32\libraries\BluetoothSerial\src/BluetoothSerial.cpp:961: undefined reference to `esp_bt_gap_cancel_discovery'
d:/tools/arduino/hardware/espressif/arduino-esp32/tools/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/8.4.0/../../../../riscv32-esp-elf/bin/ld.exe: libraries\BluetoothSerial\BluetoothSerial.cpp.o: in function `BluetoothSerial::discoverAsyncStop()':
D:\Tools\Arduino\hardware\espressif\arduino-esp32\libraries\BluetoothSerial\src/BluetoothSerial.cpp:962: undefined reference to `esp_bt_gap_cancel_discovery'
d:/tools/arduino/hardware/espressif/arduino-esp32/tools/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/8.4.0/../../../../riscv32-esp-elf/bin/ld.exe: libraries\BluetoothSerial\BluetoothSerial.cpp.o: in function `std::enable_if<std::__and_<std::__not_<std::__is_tuple_like<void (*)(std::_Any_data const&, BTAdvertisedDevice*&&)> >, std::is_move_constructible<void (*)(std::_Any_data const&, BTAdvertisedDevice*&&)>, std::is_move_assignable<void (*)(std::_Any_data const&, BTAdvertisedDevice*&&)> >::value, void>::type std::swap<void (*)(std::_Any_data const&, BTAdvertisedDevice*&&)>(void (*&)(std::_Any_data const&, BTAdvertisedDevice*&&), void (*&)(std::_Any_data const&, BTAdvertisedDevice*&&))':
d:\tools\arduino\hardware\espressif\arduino-esp32\tools\riscv32-esp-elf\riscv32-esp-elf\include\c++\8.4.0\bits/move.h:193: undefined reference to `esp_bt_gap_set_scan_mode'
d:/tools/arduino/hardware/espressif/arduino-esp32/tools/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/8.4.0/../../../../riscv32-esp-elf/bin/ld.exe: libraries\BluetoothSerial\BluetoothSerial.cpp.o: in function `BluetoothSerial::discoverAsync(std::function<void (BTAdvertisedDevice*)>, int)':
D:\Tools\Arduino\hardware\espressif\arduino-esp32\libraries\BluetoothSerial\src/BluetoothSerial.cpp:981: undefined reference to `esp_bt_gap_start_discovery'
d:/tools/arduino/hardware/espressif/arduino-esp32/tools/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/8.4.0/../../../../riscv32-esp-elf/bin/ld.exe: libraries\BluetoothSerial\BluetoothSerial.cpp.o: in function `.L0 ':
D:\Tools\Arduino\hardware\espressif\arduino-esp32\libraries\BluetoothSerial\src/BluetoothSerial.cpp:114: undefined reference to `esp_bt_gap_resolve_eir_data'
d:/tools/arduino/hardware/espressif/arduino-esp32/tools/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/8.4.0/../../../../riscv32-esp-elf/bin/ld.exe: libraries\BluetoothSerial\BluetoothSerial.cpp.o: in function `get_name_from_eir':
D:\Tools\Arduino\hardware\espressif\arduino-esp32\libraries\BluetoothSerial\src/BluetoothSerial.cpp:118: undefined reference to `esp_bt_gap_resolve_eir_data'
d:/tools/arduino/hardware/espressif/arduino-esp32/tools/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/8.4.0/../../../../riscv32-esp-elf/bin/ld.exe: libraries\BluetoothSerial\BluetoothSerial.cpp.o: in function `.L0 ':
D:\Tools\Arduino\hardware\espressif\arduino-esp32\libraries\BluetoothSerial\src/BluetoothSerial.cpp:413: undefined reference to `esp_bt_gap_cancel_discovery'
d:/tools/arduino/hardware/espressif/arduino-esp32/tools/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/8.4.0/../../../../riscv32-esp-elf/bin/ld.exe: libraries\BluetoothSerial\BluetoothSerial.cpp.o: in function `esp_bt_gap_cb':
D:\Tools\Arduino\hardware\espressif\arduino-esp32\libraries\BluetoothSerial\src/BluetoothSerial.cpp:415: undefined reference to `esp_spp_start_discovery'
d:/tools/arduino/hardware/espressif/arduino-esp32/tools/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/8.4.0/../../../../riscv32-esp-elf/bin/ld.exe: D:\Tools\Arduino\hardware\espressif\arduino-esp32\libraries\BluetoothSerial\src/BluetoothSerial.cpp:477: undefined reference to `esp_bt_gap_pin_reply'
d:/tools/arduino/hardware/espressif/arduino-esp32/tools/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/8.4.0/../../../../riscv32-esp-elf/bin/ld.exe: D:\Tools\Arduino\hardware\espressif\arduino-esp32\libraries\BluetoothSerial\src/BluetoothSerial.cpp:485: undefined reference to `esp_bt_gap_ssp_confirm_reply'
collect2.exe: error: ld returned 1 exit status

Other Steps to Reproduce

No response

I have checked existing issues, online documentation and the Troubleshooting Guide

• I confirm I have checked existing issues, online documentation and Troubleshooting guide.

[SuGlider]

Bluetooth Serial or SPP (Serial Port Profile) is part of BT 2.1 and uses RFCOMM to connect two peer devices.
It will only work for the ESP32.

ESP32-C3 has only BLE support. There is no SPP in BLE.
Therefore, BluetoothSerial will never work for the C3.

[SuGlider]

Closing it, given that there is nothing to be done, as already explained.

[lbernstone]

@SuGlider Maybe put a note on the readme for BluetoothSerial that bluetooth classic is only supported on ESP32

[QGB]

GATT (Generic Attribute profile is a BLE profile, it defines specifications for two BLE devices to communicate through Service and Characteristic, the two parties of GATT communication are Client/Server relationship, Peripheral is GATT Server, Central is the GATT Client, all the communications, both are initiated by Client, and receive the response from Server.

[summerfind]

the example of: SerialToSerialBT from Arduino IDE, passed compiling for ESP32 Dev Module, failed for ESP32 S3 Dev module, why?

[SuGlider]

the example of: SerialToSerialBT from Arduino IDE, passed compiling for ESP32 Dev Module, failed for ESP32 S3 Dev module, why?

SerialBT uses Bluetooth Classic protocol based on BR/EDR, which is only supported by the old ESP32.
ESP32-S3 and ESP32-C3 only support Bluetooth Low Energy (BLE), therefore these are incompatible with SerialBT.

For more details about comparing BT and BLE:
https://www.mathworks.com/help/bluetooth/gs/comparison-of-bluetooth-bredr-and-bluetooth-le.html