Interactive electronics resource
Electronic Dice Kit Instructions
Build, understand and experiment with the Electronic Dice Kit. This resource brings the original kit material into the current MitchElectronics format with the schematic, circuit explanation, component and PCB information, construction guidance, troubleshooting and practical ideas where available.
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!
Schematic
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).
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!
Try it yourself
Circuit simulation
Not available in mobile view
What you need
Component List
| Component | Quantity | PCB Reference |
|---|---|---|
| 16 DIP Socket | 1 | U3 |
| 8 DIP Socket | 2 | U1, U2 |
| 4017 | 1 | U3 |
| 555 | 2 | U1, U2 |
| 2N3904 | 2 | Q1, Q2 |
| 330R Resistors | 3 | R6, R7, R8 |
| 470R Resistor | 1 | R5 |
| 1K Resistor | 1 | R3 |
| 10K Resistor | 4 | R1, R2, R9, R10 |
| 680K Resistor | 1 | R4 |
| 100nF Capacitors | 6 | C2, C3, C4, C5, C6, C7 |
| 100uF Capacitor | 1 | C1 |
| Tactile Switch | 1 | SW1 |
| Red LED | 7 | D7 to D13 |
| 1N4148 | 6 | D1 to D6 |
| PP3 Connector | 1 | BT1 |
| Electronic Dice PCB | 1 | — |
Inspect the board
Interactive BOM
Board reference
PCB & assembly
The PCB silkscreen and component references should be checked against the component list before soldering each part.
Before applying power
- Check every component against its PCB reference.
- Confirm the orientation of all polarised components and ICs.
- Inspect for solder bridges, unsoldered pads and clipped leads that could cause a short.
- Check that no loose wire or solder debris remains on the board.
Build with confidence
Construction tips
Recommended build order
A reliable way to assemble Electronic Dice Kit is to work from the lowest-profile components to the tallest. This keeps the PCB easy to access while you solder.
- Fit resistors, links and other low-profile components first.
- Fit small capacitors and diodes, checking polarity where applicable.
- Fit IC sockets and small semiconductors, observing the orientation markings.
- Fit larger capacitors, potentiometers, switches and other controls.
- Fit LEDs, connectors and the remaining taller components.
- Insert socketed ICs only after soldering around the socket is complete.
- Inspect every joint and check for solder bridges before applying power.
Electronics construction guidance
If you are new to kit construction, use the Soldering Guide alongside these instructions. Identify each component before fitting it and compare its reference with the component list and PCB silkscreen.
When it does not work
Troubleshooting
Nothing happens when power is applied
- Confirm the supply is connected to the correct input and with the correct polarity.
- Check that ICs, diodes, LEDs, transistors and electrolytic capacitors are fitted in the correct orientation.
- Compare component values and positions against the component list and PCB reference.
- Inspect for missed joints, dry joints and accidental solder bridges.
The circuit powers up but does not behave as expected
This kit is intended for electronic random dice display. If the output is stuck, unstable or outside the expected behaviour, use the schematic to trace the circuit a stage at a time rather than replacing several parts at once.
Check the components around the part of the circuit responsible for the output or timing first. A misplaced resistor, reversed semiconductor or poor connection can allow a circuit to power up while preventing it from operating correctly.
The circuit works intermittently
Intermittent behaviour is often caused by a marginal solder joint, a loose connector or a component lead that has not been fully soldered. Gently inspect the board with power removed and reflow any joint that looks dull, cracked or incomplete.
If the fault remains, compare the assembled board with the schematic and PCB reference one connection at a time.
Ready to test and experiment?
Modify the dice to slowly count down instead of suddenly. This could be done by combining the Voltage Controlled Oscillator kit with an RC circuit As the voltage across an RC tank circuit falls, the output frequency of the VCO falls, and this would result in a slower count Eventually, a comparator would reset the VCO and prevent further counts after the RC voltage has reached a minimum level
Once the board is working, compare its behaviour with the schematic and the explanation above. Try changing only one input, control or permitted component value at a time so you can clearly see what effect that change has on the circuit.