No connection to ELM327

Using Arduino Programming Questions
1

Hi!

I am trying to do a similar project like on this link. I have soldered two wires to the rx and tx pins on the ELM device, which are connected to the rx and tx pins on Arduino UNO Rev3. I am also using ELM327 v1.5a.

I have modified the code to work with the lcd display I have and thats it.

When I run the program on Arduino then the ELM device seems to get the test message (ATI) because the green and yellow LEDs flash but nothing gets sent back. I have also tried ATZ command but same result.

Is there a difference between the newer release ELM device and older one used in the guide or why doesn't this work?

Code is also on the link above.

Sorry for my bad english, not my native language.

Thanks in advance for any help.
Marek

2

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3

spycatcher2k:
Have you connected the grounds?

What grounds?

4

(deleted)

5

spycatcher2k:
The ground on the Arduino and the ELM327!

Yes, the grounds are connected.

6

So no one has any idea what could be the problem?