HDD Activity Meter

20 LED versions

In this design the effect is of a pair of LEDs moving away from each other, (DOT mode), or, if using BAR mode, a row of LEDs expanding outwards away from each other.




Parts List with order codes for UK and US suppliers

20 individual LED version

As in all the board designs for the HDD meter, R3 is fitted in its alternate position and VR1 is replaced with a wire link. There is a total of three links on this board.



Component layout - top view.




Track layout - Viewed from above.



The finished board.

The PCB layout if using two 10 LED arrays

Again three links are used here.



Component layout - top view (left) and Track layout - Viewed from above (right)



The finished board.



Wiring detail between the LED arrays viewed from above.