@Gojir4 thanks, I am trying that right now. I’ve added a 1s delay in my image grabbing thread. Let’s see. Fingers crossed!

@Wieland, this float number is represent the speed Value of DC motor in RPM, may you mean I it should be in double type or something else!!.
in fact I don't know obviously whit's the type I should use this is the GUI I built
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you can see in Stack-overflow here:
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may you get what I need, I'am sory to be annoying but I spent alot of time in this problem :(

I didn't saw that there was no tooltip for them… At least there is for the flag and quote :)

Thanks :)