Dad an I made a doofer that has ten red LEDS. They flash one by one, they start from right to left. They speed along as fast as lighting.
It took heaps of soldering, I did most of it but Dad made some mistakes so he did the rest. He also burnt his own fingers. I am going to bring it to my cousin's house when I go this holiday.
by Emma.
[The design for this came from here. The mistakes in the implementation were entirely mine. That Emma was soldering with her left hand was also my fault. Things got better after she switched back to her right. The burn was inconsequential - I only said Ow! Dad.]