How to reset K8055 counters in Linux?


I have rewritten the Linux software linked from the K8055 page ( I have a good understanding of most details and can read and write to all ports.

What I don’t understand is how I should reset the counters, which seems possible according to the DLL documentation.

Any hints on this? The software writes a 0x05 in the first byte to the K8055, which i assume is some control register of some kind. Should some other value be put here? which? I have experimented and have seen various results, but no counter reset.

Thanks for any advice.


Dear sir,

Velleman doen’t support at this time no Linux software !

Oh well… let me rephrase that question then to make it platform independent. What is the byte sequence that needs to be written on the USB bus in order to have the counters reseted?

Obviously I can write to the outputs using offsets 1-3, read the counters at 4-7.
It appears the counters could be reseted using the first byte, but I have not been able to find out exactly how. It just makes the counters be random.

In any case, you may download my results this far. It is basically a simple GTK+ GUI built on the K8055 utility for Linux ( I have tried contacting the author of K8055 for Linux without and success. You find my program at There are a couple of things that could be improved but eventually I will release a new version.
Needless to say, my program can not yet reset the counters.

The byte value should be:
3 - reset pulse counter1
4 - reset pulse counter2

Have you looked the K8055D.DLL source? May be helpful.
You may download it from:

Years back (2007) I got this source code off a Vellman K8055 thread.
It’s been modified to read and write to text files called input.txt and output.txt.

You’ll need to download and install libUSB-devel before you run ./configure
The executable resides in src dir after compile, called cueib.
Copy cueib, input.txt, and output.txt to a seperate DIR and run.
Use a bash or whatever script to read and write to from input.txt and output.txt.