Trying to connect HC-05 to bluetooth OBD2 interface (elm 327)

Hello.
I am trying to pull data from the obd port of my car and read them with arduino.
Can someone explain me how can i pair the HC-05 module with the obd interface?
I've set the Hc-05 as master, but when i use AT+BIND i get error 0. I found the adress for the obd interface
in device maneger after i paired it with my PC.

nobody? :frowning:

Davaio:
I've set the Hc-05 as master,

Have you proven that with "AT+ROLE?" ?

It's easier to use an ESP32 with builtin bluetooth when interfacing with an ELM327. I've been able to successfully connect to my ELM327 both with an HC-05 and ESP32. For reference, check out this thread. More specifically, you should be interested in reply #3:

Enter the following commands after putting the HC-05 into AT mode:

  • AT
  • AT+UART=115200,0,0
  • AT+CMODE=0
  • AT+ROLE=1
  • AT+RESET
  • AT+INQM=0,5,9
  • AT+INIT
  • AT+INQ
    (discovered the address of the OBD-II scanner is 1D:A5:1F16BB - yours might be different)
  • AT+PAIR=1D,A5,1F16BB,20
  • AT+BIND=1D,A5,1F16BB
  • AT+LINK=1D,A5,1F16BB
  • AT+RESET

You may also be interested in the ELMduino.h library. It really helps make interfacing your Arduino with an ELM327 super easy and can be installed via the Arduino IDE's Libraries Manager.

Power_Broker:
It's easier to use an ESP32 with builtin bluetooth when interfacing with an ELM327.

I am looking for a module with builtin Bluetooth.
Which one do you use?

This one

Thanks! Something to do while stuck at home.

thank you for the responses but i scrapped this ideea and went with a CAN BUS connected directly to arduino.

ieee488:
I am looking for a module with builtin Bluetooth.
Which one do you use?

I found an interesting Bluetooth Dual Mode module, HC-05 only support Bluetooth Classic, as Bluetooth Low Energy becomes to be a new fashion, I think it may worth trying :smiley:

jerrywireless:
I found an interesting Bluetooth Dual Mode module, HC-05 only support Bluetooth Classic, as Bluetooth Low Energy becomes to be a new fashion, I think it may worth trying :smiley:

That's a really interesting device in the link. The ESP32 does have both standard Bluetooth and BLE, though.

jerrywireless:
I found an interesting Bluetooth Dual Mode module, HC-05 only support Bluetooth Classic, as Bluetooth Low Energy becomes to be a new fashion, I think it may worth trying :smiley:

I don't understand this. I would also be wary of it, as it might just be a packaging stunt.
I understand that standard BLE devices are backwards-compatible with BT Classic, so why is an HC-05 there? I also understand that the BLE HM-10 is not backwards compatible, but I'm not sure that justifies this device.

I also see that they promote their HC-05 as a master/slave two-in-one. Well no, actually it is just another HC-05 - made expensive by a cardboard box and a bit of superfluous plastic..

Nick_Pyner:
I don't understand this. I would also be wary of it, as it might just be a packaging stunt.
I understand that standard BLE devices are backwards-compatible with BT Classic, so why is an HC-05 there? I also understand that the BLE HM-10 is not backwards compatible, but I'm not sure that justifies this device.

I also see that they promote their HC-05 as a master/slave two-in-one. Well no, actually it is just another HC-05 - made expensive by a cardboard box and a bit of superfluous plastic..

Bluetooth classic played a very important role in the history of Bluetooth as well as some of my projects, but now I more likely to move towards BLE and maybe keep both, some OBDII devices do use BLE technology. They a lot more options that can be expected to get.

Davaio:
nobody? :frowning:

HC-05 is factory set as a slave and can communicate with a computer. When you set it to master mode it can communicate with a slave HC-05 only. You cannot pair HC-05 with Bluetooth OBD2.

eduardouk:
You cannot pair HC-05 with Bluetooth OBD2.

This is 100% false.

Why would you say this even though it was proven you can use an HC-05 to communicate with an OBDII scanner in earlier posts?