NEW >>> K8090 8-Channel USB Relay Card

is there a possibility of a connection between K8090 and an android phone ??

I believe there is only an iOS app available

I had quite a battle to get the drivers installed on Win8.1 so for those still struggling

1)Move the mouse to the top right of the screen and select the search icon from the charms

2)In the search box enter “advanced start up options”

3)You will get a list of matched applications, choose “Change advanced startup options”

4)An Update and Recovery screen will open, choose “Advanced Startup” click “Restart Now”

5)Choose an Option screen will open, click the middle option “Troubleshoot”

6)A Troubleshoot screen will open, choose the third option “Advanced Options”

7)An Advanced Options screen will open, choose the fifth option “Startup Settings”

8)A startup settings screen will open, choose “Restart”

9)The system will now reboot and you will be presented with a list of options, choose option 7 “Disable driver signature enforcement”

The system will continue to boot normally, once booted follow the given instructions to update the driver. This time the driver install will proceed, you will be told the driver is unsigned but click install anyway.

The driver install takes a few minutes, once complete you should see the board listed in device manager and the demo will run. Reboot to set your startup options back to the default. Job done!

We are currently trying to get the driver up to date for Windows 8. We hope to have this resolved by the end of the week.

A new driver is available that is compatible with Windows 8

This driver does not require you to disable Driver Signature Enforcement

I have been playing with the board for a week now. My programming language is Liberty BASIC which can create GUI style interfaces with relative ease. This is where I have got to, it’s just a bit more functional than the demo but its just a start. The button modes can be changed, the timers set and started. I have in mind a sequencer. Anyways this is what I have if you like to try you can download the .zip folder. There is no install, simply run the .exe in the folder and delete the folder when your done. It uses the serial com port to talk to the board.

The interface:

The download:

The Liberty BASIC forum if you wish to discuss the code:

I need to create a program using the K8090 in C,
and I’d like to know the status of a relay.

For example, on the relay 1, I’ve a lamp and I’d like to know if it is already on or not.
I tried with :


But I found out that the BOOL returned by that function is not the relay status, but just indicate that the command worked or not.

EDIT : And I’ve just seen that the third param is useless too for that command

So how can I get the relay status (with an example if possible)?

Sorry if my english is not perfect.

Thank you in advance.

If you’re using C you probably don’t need the dll, it’s easier just to read from or write to the COM port. The dll will only work in a windowed application, not a console application.

I need to create a program using the K8090 in Labview,
but I have no experience to create a dll to control the relay-card via Labview.

Can anyone help me?

Thx a lot!


I have the same problem like Karsten. i use the VM8090 and I need to controll it with Labview.
I tried to inculde the dll in Labview but nothing is working. :frowning:

If someone could help us would be great :slight_smile:

Sorry, we do not have any experience with Labview at this time.
Maybe a forum member can assist?

If anyone is curious on a simple way to get this working under Linux via USB I used:

With good success on Debian. Follow README and simple example for first relay:

k8090cmd -c on -r 0 k8090cmd -c off -r 0


In sample01 you can toggle all the relais.

How can i only toggle one.

I am working with visual studio 17.

Thanks Bart

Hi, I have K8090 relay board and I want write programs to read and write data using python. One program should write in Windows 10 and the other in Linux (raspberry pi). Can I get some sample codes for those if possible since I don’t have deep knowledge in programming?

Thank You !

Hi Could please share me the code. I am trying to implement functions for reading writing and status of relays. It would be helpful if I have sample code


Here is my first question.
Im using the VM 8090 and it works perfect.

For me it wouldt be very fine if the red dots on the program are changeing to green - or so - if it is on.
From dark red to red is very hard to see.

Is there a way to change it?

kind regards