Momentary button to toggle LED - LabVIEW FPGA

[muahang1234]

I have started to learn something with hardware (cRio starter kit).  I want to implement what is called "memory" in motor control  that is when I press a push button (PS1), the LED (LED1) will change its state and stay until PB1 is pressed again.  I tried to implement it but failed completely.  It should be done with a register but I just could not keep it from blinking.  

[GerdW · Accepted solution]

Hi muahang,

use a shift register to keep the previous state of the button. Compare the current state of the button with it's previous one. When you detect a rising edge you invert the boolean value of a second shift register. Write the boolean from the second shift register to your LED...

Keywords: boolean, rising edge detection, shift register

[muahang1234]

Thank you very much.  I never thought about using the second shift register to achieve it.

[GerdW]

Why didn't you think of using a second shift register? 😄

[trky34]

Dear GerdW,

I can't see the picture. Can you share it again?

[GerdW]

Hi Ayse,

no, I cannot reattach that picture. It's long time ago.

But from my description it's quite easy to recreate it from scratch:

[trky34]

🙂 Thank you very much. I am new at Labview so I can't visualize it