My hobby project :-
The word "HI" is displayed when the board is waved with our hands. Persistence of vision refers to the optical illusion where multiple discrete images blend in to single image in the human mind . The main concept has been referred from the idea of propeller clock. When normal human waves his hand the vision would be the word which they enter.
FABRICATION OF PCB BOARD
The program board is designed in such way the 8 led’s are connected form PD0 to PD7 of ATmega8.
The circuit is designed through sprint layout software.
The PCB design is printed in the photolytic sheet.
The photolytic sheet is stuck with the copper board.
It is then heated thorough ironing process
The whole board is dipped in a solution of ferric chloride
for 15 mins for etching process to occur
This process turns the copper into plastic leaving the printed design part by applying acetone on it.
The components are then drilled and soldered
------THE BELOW PICTURE IS A SINGLE LAYER PCB BOARD DESIGNED AND FABRICATED BY ME------
CALCULATION OF DELAY :-
STEP 1- Determine the rpm of waving hand, which is found to be 70 rpm.
STEP 2- One complete circle has 360 deg therefore to complete 360 deg it takes 70 revolution per min
STEP 3- Therefore it takes 1.1667 secs.
STEP 4- One full rotation : 1/1.1667=0.8571 secs.
STEP 5- One deg movement : 0.8571/360=2.38 microsecs
STEP 6- Frequency of ATmega8 = 16mhz.
STEP 7-Therefore a delay of 2 to 2.5 micro secs delay should be given.
