Bluetoothserial with Password pairing only works on ESP32 v1.0.1

[Manasmw01]

Board

ESP32

Device Description

So, there's this Code
which I am using for getting data using UART and sending that data to the Bluetooth terminal for further processing.
The only thing I want to add here is password pairing for Bluetooth.
I tried the ESP-IDF example named gatt_security_server and it works well. But I faced issues in incorporating Bluetooth Serial in it.
I also searched a lot in this, but all I can see is open issues with no solutions.
PS: The code is working fine if I downgrade the ESP32 version to 1.0.1 in Arduino IDE. I found this method in one of the comments: LINK
I was wondering if you guys could help me out so that this code works with the latest ESP32 version.

Hardware Configuration

Only serial.

Version

v1.0.6

IDE Name

Arduino IDE

Operating System

Windows 10

Flash frequency

40MHz

PSRAM enabled

no

Upload speed

115200

Description

Works with v1.0.1 but not with the latest board version

Sketch

https://github.com/espressif/arduino-esp32/blob/master/libraries/BluetoothSerial/examples/SerialToSerialBTM/SerialToSerialBTM.ino

Debug Message

No

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.

[euphi]

Example code that works fine with v1.0.1 and can't connect with v2 (v2.0.2 and latest):

#include "BluetoothSerial.h"
BluetoothSerial SerialBT;

uint8_t address[6] = { 0x20, 0x13, 0x01, 0x18, 0x02, 0x26 };
const char *pin = "1234";
bool connected;

void setup() {
  Serial.begin(115200);
  SerialBT.begin("ESPBT", true); 
  SerialBT.setPin(pin);
  Serial.println("The device started in master mode, make sure remote BT device is on!");
  
  connected = SerialBT.connect(address);
  
  if(connected) {
    Serial.println("Connected Succesfully!");
  } else {
    while(!SerialBT.connected(10000)) {
      Serial.println("Failed to connect. Make sure remote device is available and in range, then restart app."); 
    }
  }
}

void loop() {

  if (SerialBT.available()) {
    Serial.write(SerialBT.read());
  }
  delay(5);
}

Tested with platformio:

[env:esp32-v1]
platform=espressif32
board = esp32doit-devkit-v1
framework = arduino
build_flags = -DCORE_DEBUG_LEVEL=6


[env:esp32-v2.0.2]
platform = https://github.com/tasmota/platform-espressif32/releases/download/v2.0.2idf/platform-espressif32-2.0.2.zip
board = esp32doit-devkit-v1
framework = arduino
platform_packages = framework-arduinoespressif32@https://github.com/espressif/arduino-esp32.git
build_flags = -DCORE_DEBUG_LEVEL=6


[env:esp32-v2-upstream]
platform = https://github.com/platformio/platform-espressif32.git#feature/arduino-upstream
board = esp32doit-devkit-v1
framework = arduino
platform_packages = framework-arduinoespressif32@https://github.com/espressif/arduino-esp32.git
build_flags = -DCORE_DEBUG_LEVEL=6

Debug output is not helpful:

V1 (OK):

entry 0x400806a8
[I][BluetoothSerial.cpp:571] _init_bt(): device name set
[I][BluetoothSerial.cpp:243] esp_spp_cb(): ESP_SPP_INIT_EVT
[I][BluetoothSerial.cpp:126] btSetPin(): pin set
The device started in master mode, make sure remote BT device is on!
[I][BluetoothSerial.cpp:803] connect(): master : remoteAddress
[I][BluetoothSerial.cpp:324] esp_spp_cb(): ESP_SPP_DISCOVERY_COMP_EVT
[I][BluetoothSerial.cpp:326] esp_spp_cb(): ESP_SPP_DISCOVERY_COMP_EVT: spp connect to remote
[I][BluetoothSerial.cpp:351] esp_spp_cb(): ESP_SPP_CL_INIT_EVT
[I][BluetoothSerial.cpp:334] esp_spp_cb(): ESP_SPP_OPEN_EVT
Connected Succesfully!
[V][BluetoothSerial.cpp:307] esp_spp_cb(): ESP_SPP_DATA_IND_EVT len=90 handle=129
[V][BluetoothSerial.cpp:307] esp_spp_cb(): ESP_SPP_DATA_IND_EVT len=1 handle=129
[V][BluetoothSerial.cpp:307] esp_spp_cb(): ESP_SPP_DATA_IND_EVT len=64 handle=129
[V][BluetoothSerial.cpp:307] esp_spp_cb(): ESP_SPP_DATA_IND_EVT len=26 handle=129
L5,004000,0,0,4150,4151,4152,287,0,298,1,240,1699,13250,25930;
$FLB,850,99319,2113,0;
[...]

V2 Upstream (not OK):

entry 0x400805e4
[␀␘␂␂␂��m␑um����2-hal-cpu.c:211] setCpuFrequencyMhz(): PLL: 480 / 2 = 240 Mhz, APB: 80000000 Hz
[   562][I][BluetoothSerial.cpp:622] _init_bt(): device name set
[   567][I][BluetoothSerial.cpp:251] esp_spp_cb(): ESP_SPP_INIT_EVT
[   570][I][BluetoothSerial.cpp:134] btSetPin(): pin set
The device started in master mode, make sure remote BT device is on!
[   581][I][BluetoothSerial.cpp:867] connect(): master : remoteAddress
[  1683][I][BluetoothSerial.cpp:336] esp_spp_cb(): ESP_SPP_DISCOVERY_COMP_EVT
[  1684][I][BluetoothSerial.cpp:338] esp_spp_cb(): ESP_SPP_DISCOVERY_COMP_EVT: spp connect to remote
[  1690][I][BluetoothSerial.cpp:363] esp_spp_cb(): ESP_SPP_CL_INIT_EVT
Failed to connect. Make sure remote device is available and in range, then restart app.
Failed to connect. Make sure remote device is available and in range, then restart app.
[ 31849][I][BluetoothSerial.cpp:283] esp_spp_cb(): ESP_SPP_CLOSE_EVT: 0

platformio-project:

esp32-issue6061.zip

BLE works fine with 2.0.2.

[euphi]

Is it easily possible to increase debug-level of the IDF/BlueDroid? (using platformio).

I tried the IDF SPP_INITIATOR_DEMO and this also can't connect.
When connecting by directly using the adress, the connection is initiated (ESP_SPP_CL_INIT_EVT) but then fails with
mW (36287) BT_RFCOMM: port_rfc_closed RFCOMM connection in state 1 closed: Peer connection failed (res: 16)

[SuGlider]

Try calling setPin() before begin().

void setup() {
  Serial.begin(115200);
  SerialBT.setPin(pin);    // setPin() shall come before begin()
  SerialBT.begin("ESPBT", true); 
  Serial.println("The device started in master mode, make sure remote BT device is on!");
  
  connected = SerialBT.connect(address);
  
  if(connected) {
    Serial.println("Connected Succesfully!");
  } else {
    while(!SerialBT.connected(10000)) {
      Serial.println("Failed to connect. Make sure remote device is available and in range, then restart app."); 
    }
  }
}

[euphi]

@SuGlider thanks for the hint, but it does not solve the issue. I suspect that cause is lying "deeper", so I opened an issue at espressif/esp-idf.

[euphi]

Workaround:

I was able to connect with Arduino-ESP32 2.0.2, by using an own SDK configuration that disables SSP.

See https://community.platformio.org/t/using-latest-esp32-arduino-but-with-own-idf-configuration/26000/2 :

platformio.ini:

[env:esp32-v2-upstream]
platform = https://github.com/Jason2866/platform-espressif32/releases/download/v2.0.2/platform-espressif32-2.0.2.zip
board = esp32doit-devkit-v1
framework = arduino, espidf
platform_packages = framework-arduinoespressif32@https://github.com/espressif/arduino-esp32.git

SDK-Config: https://github.com/euphi/ESP32_BTTacho/blob/main/sdkconfig.esp32-v2-upstream

Patch for BluetoothSerial.cpp (commenting out symbols that need SSP enabled):
https://github.com/euphi/ESP32_BTTacho/blob/main/framework-arduino-esp32-BTSerial.patch

[cattledogGH]

In my testing with trying to connect an ESP32 using the Arduino core as Bluetooth Serial Master to an HC05 in slave mode, failure to connect begins with any version after 1.0.6.

I think that the issue is with the change from
ESP-IDF v3.3.5 to ESP-IDF 4.4. used by the Arduino core. I'm not clear if there were any versions of the ESP-IDF used in the core between these two versions, so the observation is that the problem is associated with ESP-IDF 4.3.2 may be correct.

[VojtechBartoska]

Hello, can you please retest this on v2.0.3-rc1?

[cattledogGH]

@VojtechBartoska
v2.0.3-rc1 exhibits the failure of BT master to connect with an HC05.

[euphi]

As already mentioned the problem lays "deeper":
The problem can be reproduced without using Arduino framework, but IDF only. So root cause is in the IDF: espressif/esp-idf#8394 .