The 4017 counter is a highly versatile and easy to use device. It counts from 0 to 9 and gives the result on one of its 10 output pins. In the dice circuit, the count range needs to be restricted to the range 0 - 5 (six separate numbers) by connecting output 6 to the reset pin. For simplicity, the example circuits use a virtual 2KHz test signal. For a real circuit, you need to replace this with a signal from a fast astable.
| } | ress SW1 to 'roll' the dice |
The circuit shown is for low current LEDs which give good illumination from CMOS outputs. e.g. Rapid part no. 56-0415 Standard LEDs will give disappointing light output unless they are driven by transducer drivers. CircuitWizard does not (as yet) include low current LEDs in its gallery so R3 has been set to 180R. With low current LEDs you can set R3 to 1K.
Note: As only one LED can possibly be on at one time, only one limiting resistor (R3) is required.
This circuit is easily modified to produce a heads or tails game by:
| ¡ | Omitting D3 - D6 |
| ¡ | Moving the reset connection from output 6 to output 2 |