Fearless Night

Zen Dice II

A truly random electronic dice and random number generator, times two.

Zen Dice II uses Zener avalanche technology to generate truly random dice rolls, decisions, and random numbers. The display is a pair of three color 8x8 LED arrays. Self-diagnostics insure that the random number generator is working reliably.

There are seven modes to choose from, click on a thumbnail for a bigger picture:

Double 6-sided Dice |
Double 20-sided Dice |

Double Heads/Tails Coin Flip |
Double Yes/No Decision Maker |

Decimal Random Number Generator |
Hex Random Number Generator |

Random 3-color Stars |

Operation

Press the POWER/MODE button to power on and select the desired random generator mode.

Hold the POWER/MODE button for 2 seconds to power off.

Press a ROLL button to generate a random result.

The device will automatically power off after 5 minutes of inactivity.

Operating Modes

The POWER/MODE button cycles through the operating modes, plus the diagnostic modes if they are enabled (see below).

Mode #1 - 6 Sided Dice | Two independent 6 sided dice. |

Mode #2 - Heads/Tails Coin Flip | Two independent coins. 'H' for Heads, 'T' for Tails. |

Mode #3 - Yes/No Decision Maker | Two independent decisions. 'Y' for Yes, 'N' for No. |

Mode #4 - 20 Sided Dice | Two independent 20 sided dice. |

Mode #5 - Decimal Random Number | Two independent random number generators, 0 to 99. |

Mode #6 - Hex Random Number | Two independent random number generators, 0x00 to 0xFF (0 to 255). |

Mode #7 - Random Stars Display | Continuous display of pixels chosen by the random number generator. |

Error Codes

The self-monitoring checks the random number generator hardware parameters to make sure that it's operating reliably.
If it's not operating within specifications then an error code will be displayed when a ROLL button is pressed.

E1 | Boost voltage out of range |

E2 | RNG signal rate not rational |

E3 | Probability space reduction failed (indicates bad RNG source) |

Diagnostic Modes

To enable the additional diagnostic modes hold down the left ROLL button while powering on.

Diagnostic #1 | Displays the boost voltage, which should be between 19 and 21 volts |

Diagnostic #2 | Displays RNG min and max events/ms, should be between 10 and 200 |

Diagnostic #3 | Statistical analysis results for maximum run length of 0's and 1's |

Diagnostic #4 | Statistical analysis results for 0/1 bias test |

Design Documents

Schematic Diagram | schematic_j720_zen_dice_2.pdf |

3D Print Files | mechanical_j720_zen_dice_2.zip |

PCB Gerbers | gerbers_j720_zen_dice_2.zip |

Source Code (Arduino) | code_j720_zen_dice_2.zip |

Source Code (PHP) | php_j720_zen_dice_2.zip |

Specifications

Power Requirement | 5V Micro USB Charger |

Dimensions | 103x103x26 mm (4x4x1 in.) |

Purchase

Available fully assembled and tested |

Buy it at Tindie |