Led cube, 3mm blue LED’s in a 8x8x8 matrix.

I made this in december 2006. avr controller and a couple of i2c chips to drive the anodes.

The base is made of wood.

Top plate is a blank pcb, I simply scored lines in it with a knife, drilled holes in the matrix patter, then painted the top. The LED cube was then inserted in the holes and soldered on the bottom side of the circuit board.

Of course, I could have made the whole circuit in smd on that board, but for one-off projects like this I prefer to use boards with holes and wire everything up. Microcontroller circuits like this are so simple you do not really need a schematic to understand it, just the data sheets for the specific ic’s.

This is made with an Atmel Mega8. I used avr gcc, and avrlib for the i2c routines. It was very easy to get this working with avrlib. I still remember when I made my mp3 player with an 6811F1, also with gcc, I had to write my own i2c routines, and even an assembly startup file.

The columns are driven by 4 SAA1064 ic’s. Normally these are used to drive 4 digit displays, but they can also be used as 16 current sink’s, with current control. I prefer current controlled drivers for LED’s instead of resistors. A bit more uniform led control, and you can modify the current setting in software.

Row’s are handled by  a 74hct138, driving 8 mosfet’s. One button on the back to choose between different patterns, or cycle between patterns.

 

Only a couple of patterns were made, the most interesting ones were “rain”, “flock” and “game of live”. Patterns with randomness are always interesting…

And for people interested in some code: blueCube Source Code