Reading data from serial port

Since it looks like you’ve never really done a serial terminal with Xojo, I would first get your communications and command structure ironed out using a dedicated terminal (e.g. Teraterm, Coolterm). You can then follow the SFE example @Norman Palardy & @Ulrich Bogun suggested. Something like (but seriously I would just run through the SFE tutorial):

command: ATZ … wait for response ... command: ATDP … wait for response ... command: AT@1 … wait for response ... command: ATRV

Once you have the cable talking to a dedicated serial terminal, then I would move to coding the desired commands and response capturing in Xojo. - I would do it this way even if I was seasoned doing serial terminals in XOJO (just until I understood very clearly how to structure the commands and how to expect the responses).

How are the wires connected, is it a pre-build cable ?

Yes, it is pre-built and in working condition.
From xojo application, when a command is sent over the cable to OBD II port of any car, indicator on the OBD II connector blinks. So command is actively going on the cable. But, no response is received.

Tried with CoolTerm and goSerial Applications … no response received. I ordered a new generic cable and will test again tomorrow :slight_smile:
Thanks to all for your help!

The issue I am seeing seems to be mac related as per this thread:
http://forums.the-meiers.org/viewtopic.php?f=4&t=535
But why would the same cable work flawlessly with diagnosis software of the car …

@Chakravarthy Cuddapah
Something is not making sense on this whole thread. Here you mentioned that the cable works without problems on Windows but you can’t get it to communicate in XOJO.

Here you say is not working in a MAC

Wouldn’t you think it would be easier to just keep one variable constant instead of trying to change serial terminals and computing platforms?

If it were me I would choose whichever platform it is working on, and then try the more common serial terminals there. As an example, if it works in Windows (with their software) I would try with Coolterm and Teraterm. One was done in XOJO and the other wasn’t… But I would not be jumping platforms left and right just to keep trying, otherwise why not go ahead and try Linux while you are at it.

Good News!
I bought this generic cable from Amazon:
https://www.amazon.com/gp/product/B01MQD1NB8/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
This cable supports all OBD II protocols.
Now, CoolTerm and my xojo application are able to talk with OBD II port in my car and receive data!
Thanks everyone for your responses to my questions.