Freematics Forum

Hi
About a year ago we purchased a couple of adapters to connect to our board so we can read the RPM
lately we ordered some more, but I get different data via the UART read,including NO DATA, which outcomes as a 0 RPM.
Is there a difference between the 2 adapters, and how should I deal with this problem?

Maccabi

You are using the same code?

stanley wrote:You are using the same code?

using the same code, and yesterday I actually tried the old adapter that worked fine

Using the same code and it works fine with the older adapter

That's quite weird. They are only different in voltage step down module.

Hi Stanly,

After opening the two adapters, I see quite a bit of differences.
Attached is a doc file with pictures of adapter boards - both sides.
The blue card is the old one.
Thanks

Maccabi

I just committed a fix for current issue. Please update your OBD library with the latest revision in github and give another try.

I dont think I am using the OBD library.
I am only using the UART adapter with our board and code

What's your initialization code like?

Hi
In the mean time I overcame the problem, after finding out that the new adapters respond with the right protocol all the time,
only with a larger interval between requests to OBD.
In details:
After connecting a new OBD adapter cable, the RPM and speed tend to show 0, from time to time.
1. We have the 2 old connectors that work fine with 21 mls intervals between requests for SPD or RPM, and 25 mls for SPD and RPM together.
2. The new adapter needs around 34 mls between each OBD request (for SPD and RPM together).
3. The other new adapter I tested has a worse timing problem. It needs around 62.5 mls between each OBD request (for SPD and RPM together).

seems the change in voltage has affected our system timing.
I will later on be checking out other new adapters we have.
I will appreciate if you check out your side what can be done.

Maccabi