A few different points that may or may not be of use to you: 1) For best timing with metro, be sure that Overdrive is checked in the Options menu. 2) Screen drawing operations are considered low priority, so they may be affected by strong demands in other timing-critical areas. 3) The button object has its own built-in on-off flash time that is already pretty close to 200 ms, so the flashing at that rate may not always appear obviously to be 5 times per second. 4) If you want to build your own flashing graphic in lcd, as shown in the example below, you have more control over the flash duration. 5) Screen drawing operations can be rather "expensive" computationally, so you might question whether this particular flashing button is really necessary. 6) A button flashing constantly 5 times per second does show that something is happening at a fast rate, but beyond that, it doesn't really provide all that much useful information. Maybe just a toggle or a LED showing that the metro is on would be sufficient from a GUI standpoint, and would save a lot of screen drawing.

thank you for your reply. I didn't realise how much processing it took to flash an led/button on screen.

The flashing signal is to be routed to an arduino, then to a control panel. its only flashing so the eye can spot it quickly. when the user pushes the button, the led remains on.

I shall look into the LCD object it looks very interesting .

I think i can make my patch more efficient also,. as its becoming a mess . a tidy up should help. : )

Thanks again : )