Bluetooth connection to ELM237 ODB2 Interface

[digidax]

Hi,

have trying to connect to a Bluetooth ELM237 adapter. Doing this with the Android app "Serial bluetooth terminal" is working fine but can't do it with the ESP32 example:

Code: Select all

//This example code is in the Public Domain (or CC0 licensed, at your option.)
//By Victor Tchistiak - 2019
//
//This example demostrates master mode bluetooth connection and pin 
//it creates a bridge between Serial and Classical Bluetooth (SPP)
//this is an extention of the SerialToSerialBT example by Evandro Copercini - 2018
//

#include "BluetoothSerial.h"

BluetoothSerial SerialBT;

String MACadd = "AA:BB:CC:11:22:33";
uint8_t address[6]  = {0xAA, 0xBB, 0xCC, 0x11, 0x22, 0x33};
//uint8_t address[6]  = {0x00, 0x1D, 0xA5, 0x02, 0xC3, 0x22};
String name = "OBDII";
char *pin = "1234"; //<- standard pin would be provided by default
bool connected;

void setup() {
  Serial.begin(115200);
  //SerialBT.setPin(pin);
  SerialBT.begin("ESP32test", true); 
  //SerialBT.setPin(pin);
  Serial.println("The device started in master mode, make sure remote BT device is on!");
  
  // connect(address) is fast (upto 10 secs max), connect(name) is slow (upto 30 secs max) as it needs
  // to resolve name to address first, but it allows to connect to different devices with the same name.
  // Set CoreDebugLevel to Info to view devices bluetooth address and device names
  connected = SerialBT.connect(name);
  //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."); 
    }
  }
  // disconnect() may take upto 10 secs max
  if (SerialBT.disconnect()) {
    Serial.println("Disconnected Succesfully!");
  }
  // this would reconnect to the name(will use address, if resolved) or address used with connect(name/address).
  SerialBT.connect();
}

void loop() {
  if (Serial.available()) {
    SerialBT.write(Serial.read());
  }
  if (SerialBT.available()) {
    Serial.write(SerialBT.read());
  }
  delay(20);
}

get this output on serial monitor:

Code: Select all

rst:0xc (SW_CPU_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:1
load:0x3fff0018,len:4
load:0x3fff001c,len:1216
ho 0 tail 12 room 4
load:0x40078000,len:9720
ho 0 tail 12 room 4
load:0x40080400,len:6352
entry 0x400806b8
[I][BluetoothSerial.cpp:510] _init_bt(): device name set
The device started in master mode, make sure remote BT device is on!
[I][BluetoothSerial.cpp:225] esp_spp_cb(): ESP_SPP_INIT_EVT
[I][BluetoothSerial.cpp:722] connect(): master : remoteAddress
[I][BluetoothSerial.cpp:290] esp_spp_cb(): ESP_SPP_DISCOVERY_COMP_EVT
Connected Succesfully!
[I][BluetoothSerial.cpp:735] connect(): master : remoteAddress
[I][BluetoothSerial.cpp:290] esp_spp_cb(): ESP_SPP_DISCOVERY_COMP_EVT

No reaction when I do send a command. Also stupid, after some times when no other bluetooth device is present, it shows also "Connceted", Is there any way for getting more detailed debug infos? Have tried to set the name and also the MAC address (seen in serial bluetooth terminal) for the connecting info.

Does anyone have an useful hint please?

Thanks, Frank