Electronic Dice EXTC Engineering

Abstract— Playing with dice is an age-old game. We all love to play with it too. Playing with dice needs us to pick up a dice and make sure that it is unbiased. Making a block as a dice and cutting it clearly to make sure that it is unbiased is all an old story. The dice becomes biased if the shape is not cut well.

Also, the dice can become biased due to deformations. If it is a wooden die, it can deform due to dampness in the atmosphere or due to mechanical stress. To solve all these problems which we have with a conventional dice, we have made a dice circuit which solves all the problems of a conventional dice.

I. Introduction

Dice is used to play many games like snake ladder, Ludo etc. Generally, dice is made up of wooden or plastic, which gets deformed with time and become biased. A Digital dice is a good alternative of old-fashioned dice, it can’t be biased or deformed. It operates at such high speed that no one can cheat. To create this digital dice circuit, we have mainly used 555 timer IC and 4017 IC.

An electronic LED dice which is nearly unbiased. There is no chance to cheat as the circuit operates at such a high speed that the circuit is almost imperceptible to the human eye. There is also little maintenance and there is hardly any impact on aging of the circuit. The frequency may vary a bit with change in power supply voltage, aging of the active and passive components but still the randomness will be preserved without any trouble.

II. Construction

This circuit uses 555 timer as an astable multivibrator. In this mode, the circuit is arranged with R2 = 100 KΩ, R3 = 100 KΩ and C2 = 0.1 µF.

With this configuration, the circuit operates as a pulse generator with a frequency in order of kilo hertz. This means that the circuit produces a clock cycle of about 0.000210 seconds which is imperceptible to the human eye. We cannot observe the values which change at that faster rate so there is hardly any possibility of getting the dice biased.

If the count is 1, LED-1 will glow. If the count if 2, LED-2 will glow and so on until the sixth count. When the count is six, the sixth LED will glow and after that for the next clock pulse the counter will advance and the count increments to seven. In this count, the circuit resets itself as the seventh count is given to the reset pin which is PIN-15.

This is how the circuit functions and you can increase the frequency of the circuit if you feel that you need more randomness so that it is very hard to perceive. This circuit can be implemented on a general-purpose PCB with a 9V DC power supply.

III. LIST OF COMPONENTS

LEDs X 6
555 Timer IC
CD4017 Decade Counter IC
Resistors – 2.2KΩ, 100KΩ X 2
Capacitors – 1nF and 0.1µF
Push Button
9V Battery
Breadboard
Connecting Wires

IV. WORKING

The 555 Timer IC is an integrated circuit (chip) implementing a variety of timer and multivibrator applications Depending on the manufacturer, the standard 555 package includes over 20 transistors, 2 diodes and 15 resistors on a silicon chip installed in an 8-pin mini dual-in-line package (DIP-8).[4]

The 555 has three operating modes:

Monostable mode: in this mode, the 555 functions as a “one-shot”. Applications include timers, missing pulse detection, bounce free switches, touch switches, frequency divider, capacitance measurement, pulse-width modulation (PWM) etc.

Astable – free running mode: the 555 can operate as an oscillator. Uses include LED and lamp flashers, pulse generation, logic clocks, tone generation, security alarms, pulse position modulation, etc.

Bistable mode or Schmitt trigger: the 555 can operate as a flip-flop, if the DIS pin is not connected and no capacitor is used. Uses include bounce free latched switches, etc.

4017 IC is a CMOS decade counter chip. It can produce output at the 10 pins (Q0 – Q9) sequentially, means it produce output one by one at the 10 output pins. This output is controlled through the clock pulse at PIN 14. At first, output at Q0 (PIN 3) is HIGH, then with each clock pulse, output advance to the next PIN. Like one clock pulse makes the Q0 LOW and Q1 HIGH, and then the next clock pulse makes the Q1 LOW and Q2 HIGH, and so on. After the Q9, it will start from the Q0 again. So, it creates sequential ON and OFF of all the 10 OUTPUT PINs. Below is the PIN diagram and PIN description of 4017:

This circuit uses 555 timer as an astable multivibrator. In this mode, the circuit is arranged with R2 = 100 KΩ, R3 = 100 KΩ and C2 = 0.1 µF.

The power supply pin and ground are not shown in the circuit diagram as it is the schematic generated by the software Proteus. However, the power supply of 9V is given to the 16th pin of IC 4017 and the 8th pin of IC 4017 is given to ground. This is how the circuit functions and you can increase the frequency of the circuit if you feel that you need more randomness so that it is very hard to perceive. This circuit can be implemented on a general-purpose PCB with a 9V DC power supply.

V. Result

The clock pulses are given to a counter cum decoder circuit made with flip flops with the seventh output given to reset. It has nine possible outputs out of which, the seventh is given to reset because we only need a count up to 6 as a dice has six faces only. The first six outputs are given respectively to the LEDs, so that the respective LED will glow for the corresponding count.