USB bluetooth dongle with PuTTY

2
votes

I have a USB Bluetooth dongle that I am trying to use in order to extract information from an ELM327 OBD-II interface.

I am trying to communicate with the ELM327 through PuTTY. According to the ELM327 documentation, I need to use baud rate 38,400 if the PP 0C pin hasn't been changed or 9,600 if pin 6 = 0 V.

I tried setting PuTTY according to the Device Manager details with:

  • Baud rate 9,600 or 38,400

  • 8 data bits

  • No parity

  • 1 stop bits

  • No flow control

When I open PuTTY, the window is blank, and I cannot send commands to the device. What could be the issue here?

1
bluetoothputtyobd-iidongleelm327
I am having a similar issue but with the ELM327-USB interface... – jchanger
I have solved my problem on Windows 10. What operating system are you using for running PuTTy? – jchanger
@jessag Windows 10 – Kobbi Gal

1 Answers

2
votes

Your problem might be with PuTTY and Windows 10. Neither PuTTY nor Hyperterminal allowed me to connect to my ELM327 on Windows 10 (I am using the USB connection for talking to ELM327). It might be some kind of problem of these software on the latest version on Windows.

Looking for a similar software that works well on Windows 10 I found RealTerm. You can download it from this link. A brief tutorial about how to use RealTerm is available here (pay attention to the procedure to open a serial port by clicking twice on the button "open", an how to send commands from the send tab).

After downloading it, just configure your serial connection with the values you were using:

  1. Baud rate 38,400 (or 9,600)
  2. 8 data bits
  3. No parity
  4. 1 stop bits
  5. No flow control

Also, do not forget to add a CR (carriage return) at the end of the commands you send to the ELM327, if you forget it, the ELM327 will ignore the commands. You can do it by clicking on the EOL options shown in the figure below.

Enter image description here

This solved my problem and now I am able to talk to the ELM327 and receive its answers, e.g. the commands atz returns the ELM327 version. The OBD2 command 0100 returns the PIDs available on a car's ECU. I don't know why but the CR is shown on the RealTerm display and hides some characters (as it happens with the 'a' of the "atz" command in the figure).

I hope this helps you.