EmbeddedEric saw last week’s Oscilloscope Christmas Tree post, and decided it would be a fun project to do with his kids. He writes:

I thought this would be a fun project to replicate with my 2 and 4 year old daughters, but I wanted to make a small tweak and display a picture of Frosty the Snowman. My two year old discovered the old Frosty the Snowman cartoons this year and is constantly asking to “watch a frosty”.

I downloaded John’s Arduino sketch and took a look at it to see what I’d have to do to change the picture displayed on the scope. His code is very well laid out and the picture is defined by the number of points and the X Y coordinates stored as two arrays.

Now how do I draw a picture of a snowman and get X Y coordinates out of it? I tried GIMP and Paint, but ended up using Scilab…… yes a fancy math program to draw a snowman! The nice thing about Scilab is you can plot pictures using the same X & Y arrays needed for the Arduino sketch.

I could have gotten all fancy and used sin & cos equations to get a nice smooth circle, but a line segment circle gets the job done too, and is equally impressive to a two year old 🙂

…

My daughters had fun making him taller and shorter and skinny and fat all with a few button presses.

🙂 Awesome!

Source code and more at his blog. Nice work, Eric!

Editor’s note: Something which I neglected to mention when I originally posted the Christmas Tree was that I used the Eagle PCB editor to generate the drawing points. I enclosed a square 2.56″x2.56″ and then did my drawing in there, with a 0.01″ snap, using the line tool. Then I simply multiplied by 100 to get the points for the matrix. One of the nice things about Eagle is that the window needn’t be active for the coordinates to be “live”, so you can type into the Arduino IDE without having to go back and forth between them — just mouse over the point of interest. Thought I’d share that, since I forgot to mention it before.