TimeRuler is a time-space measuring tool, using light-painting technique. It can be used for fun, for measuring high speed movement in different sports or as an educational device for schools.
What you need:
Step 1: Wiring, testing
int delt=9; //delay time 9 ms - set this to 99
int blit=0.1; //delay time 0.1 ms - set this to 1
Step 2: Making the box
Build a box from plywood. The assembled box size is 62*85*77 mm (2.44*3.34*3.03 inch)
copy with the help of a carbon paper the blue outline on the black cardboard and cut out the shapes carefully. Stick tracing paper on the back of the cardboard - this will diffuse the light. These blue lines are inset 1 mm, because it is hard to make precise holes in the plywood.
Step 3: Solder, mount
Step 4: On-Off
Make a hole, where the Arduino has it's power socket, insert the plug, than mount the battery outside the box with a velcro. I used this this improvised ON-OFF system instead of buttons. to have smoother and faster start. When i push the cable to the plus end, than the animation starts automatically.
Set your camera to a few seconds long exposure with self timer, than paint some light in a dark space. Adjust ISO and aperture until you got the desired quality. Additionally if you want the painter to be visible in the picture you can give him/her a radio trigger, which is triggering a flashlight.
Play, Measure, Enjoy
Thanks for Midlands Makerspace Athlone for the helping me with Arduino.