Electronic dice has option for 20 or 100 sides

[Bluewraith] built himself an electronic dice using a 555 timer and 4017 counter. This is a classic project and he enjoyed doing it but wondered about making a 20-sided dice. So he grabbed his Arduino and got to work. A switch on the final project selects between 20 or 100 sides. He used a MAX7219 to control the 7-segment displays, and a standalone AVR chip for the rest of it.

If you missed it back in October you should also look in on this 6-sided dice. It also uses an AVR running the Arduino bootloader but a mercury switch allows the player to shake the box in order to start a roll.

One last note, we made a conscious decision to use the word ‘Dice’ instead of the grammatically correct ‘Die’ which is its singular version. We think ‘Die’ can be a bit too confusing and we’re not the only ones.

Ikea LED matrix

8x8

[Spikenzie] has created an 8×8 LED array that fits inside an ikea frame. He multiplexed the 64 red LEDs on a PCB with connections on the back. He then used a MAX7129, an LED multiplexer and driver, driven by a PIC over SPI to do animations and play pong. He then encased the array in laser-cut cardboard and white acrylic to get large dots. This entire assembly was then placed inside an Ikea RIBBA picture frame. The result is an aesthetic homebrew display that is easy to control.

Related: 64pixels are enough

AVR ATtiny25 USB hit counter

[Bob] has a USB page hit counter that uses an ATtiny25 to run a MAX7219 which drives eight 7-segment displays. It is easy to implement USB on an AVR using just firmware, eliminating the need for any USB to RS232 conversion. The host software is written in Delphi and sits in the Windows tray. The code examples seem simple enough to expand upon into your own display programs.