ELECTRONIC DICE KIT INSTRUCTIONS

Table of contents

1. Introduction
2. Schematic
3. Simulation
4. How It Works
5. Component List
6. PCB
7. Project Ideas
8. Going Further

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SCHEMATIC

SIMULATION

INTRODUCTION

If you find yourself inside on a rainy day and without dice to play your favourite board games then look no further as the MitchElectronics Electronic Dice kit is just for you!

Built using three main sub-circuits this kit will simulate a dice with a simple cool-down system so you can watch the numbers roll. Press and hold the switch to start the dice rolling and then let go when your feeling lucking for that number which gets you past those expensive hotels or away from that ladder!

HOW DOES THE ELECTRONIC DICE WORK?

Overview

The Electronic Dice kit is an … electronic dice … which can be used in place of dice for board games and other dice applications. When the user presses and holds the switch (SW1), the circuit rolls the dice and when the user lets go of the roll button the dice continue to roll for a short amount of time before landing on the final value.

This project relies on three main sub-circuits which include

✓ - 555 Monostable circuit (U1)

✓ - 555 Astable circuit (U2)

✓ - 4017 counter (U3)

The function of the monostable and astable will not be covered here but can be learned from the other MitchElectronics kits found in the links above.

Retriggerable 555 Monostable

When the button is pressed and held the two transistors Q1 and Q2 are turned on. Q1 is connected to the trigger input of the 555 monostable U1 and so this causes the monostable to trigger. However, Q2 is connected across the timing capacitor C1 for the monostable and this discharges C1. C1 can only begin to charge when the user releases the button and so this is a 555 monostable that can be retriggered as well as held before starting the countdown.

Dice Counter

The 555 monostable (U1) is used to enable the 555 astable (U2) which acts as the clock source for the dice. Normally, the 555 monostable output is low and this keeps the 555 astable from oscillating but when the button is pressed and the monostable output goes high the 555 astable (U2) begins to oscillate.

The 555 astable is connected to the 4017 counters clock input so every time the 555 astable output (U2) goes from low to high the 4017 increments. The outputs of the 4017 are configured with diodes to create the pattern of the dice faces in the LEDs and upon counting more than 6 times the 4017 resets itself (by connecting Q6 which is the 7th output to the reset input).

Component List

Component	PCB Reference	Quantity	Looks Like
8 DIP Socket	U1, U2	2
16 DIP Socket	U3	1
555 Timer IC	U1, U2	2
4017 Counter IC	U3	1
2N3904 NPN Transistor	Q1, Q2	2
330R Resistor	R6, R7, R8	3
470R Resistor	R5	1
1K Resistor	R3	1
10K Resistor	R1, R2, R9, R10	4
680K Resistor	R4	1
100nF Ceramic Disc Capacitor	C2, C3, C4, C5, C6, C7	6
100uF Electrolytic Capacitor	C1	1
Tactile Switch	SW1	1
3mm Red LED	D7 - D13	7
1N4148 Diode	D1 - D6	6
PP3 Connector	BT1	1

PCB

PROJECT IDEAS

Board Game Dice

By far, the best use for the Electronic Dice Kit is board games. The project could easily be mounted inside an enclosure while the LEDs are made visible through an opening with semi-transparent black acrylic.

But this project could easily be combined with multiple Electronic Dice Projects to create two simultaneous dice that roll either in sync or roll one after the other. Either way, it would be impossible to cheat with these dice!

Construction Tips