Electronic Dice Circuit (555 + 4017) – B2P12
A binary counter can be used to create some interesting circuits and an electronic dice is one of them. The circuit is very similar to the previous one so let’s start by taking a look at the schematic.
We have a 555 timer configured in the astable mode, but instead of the 1Hz frequency used previously, we increase it to about 48Hz so that you can’t easily manipulate the result. Instead of feeding the clock directly, we add a switch in between which means that the 4017 counter will only count when the switch is pressed and it will hold on to its count when the switch is released.
Since a dice has 6 outputs, we connect 6 different LEDs to the output pins and we connect the 7th output back to the reset pin. This way, the 4017 counter will reset itself and start counting from 0 after 6. In digital electronics, we start counting from 0, so when I say that we connect the 7th output to reset, I mean we connect output pin 6 to the reset pin as shown in the schematic.
Here’s what the assembled PCB looks like. Pressing the switch allows the clock pulses to reach the 4017 counter and the result can be viewed when the switch is released.