Nixie Driver Board Rev B

Last Modified: February 14, 2012


 

Overview

The Cogwheel Circuitworks Nixie Driver is a compact circuit board designed to drive a wide variety of gas-discharge display tubes in an 8 anode, 16 cathode multiplexed arrangement. Ample I/O options are provided for including on-board buttons, USB device, as well as wireless. High-voltage is generated by a hardware PWM under total software control. Precision time-keeping is provided by a battery-backed, temperature-controlled crystal oscillator. An Atmel ATmega 328 processor utilizes the same software development tools as the popular Arduino series. The entire hardware design, along with a complete clock/display source code are available under an attribution/open-derivative license.

Changes From Revision A

The Revision B board differs from the Revision A board in the following ways:

  • The Real-Time Clock that used to be made up of the Maxim DS1302 real-time clock and Maxim DS32khz battery-backed, temperature compensated crystal oscillator has been replaced with a single-chip Maxim DS3232 which which combines the functionality of the two and provides even more accurate time-keeping.
  • An N-channel MOSFET capable of driving 1.7A has been added to drive LEDs. Positions for 8 LEDs underneath the on-board IN17 tube sockets are provided
  • Serial Data arriving from the Bluetooth module is logically ORd with the USB Serial data before it is sent to the the ATMega microcontroller, allowing the board to be controlled simultaneously from either source.
  • Several minor changes to layout.

Features

  • High-voltage generation up to 250V
  • 24 channels of Supertexhigh voltage push-pull drivers (8 high side, 16 low side). Can drive:
    • Up 128 individual neon lights
    • Up to 8 regular nixie tubes
    • Large, multi-element nixie tubes such as B7971s
  • Powered by 12-24 VDC @ 300ma max
  • ATmega 328P processor with standard AVR ISP programming socket
  • FTDI FT232R USB Interface 100% comptable with Arduino boot loader
  • Maxim DS3232 battery-backed, temperature compensated crystal oscillator provides time-keeping accuracy to within +/- 2 ppm/yr
  • Optional on-board Roving Networks RN-41 Bluetooth Module for wireless operation
  • Positions for 8 on-board IN17x7 nixie tubes
  • Piezoelectric Transducer for Audio Alert

Applications

  • Nixie tube clocks
  • Numerical read-outs
  • Information Displays
  • Discrete neon dot-matrix displays

Block Diagram

 

High-Voltage Pin Out

Other Pin Outs

AVR ISP

The AVR ISP socket is used during manufacture to program the Arduino boot loader. Pin out is compatible with the AVR ISP connector found on Arduino compatible boards such as the Arduino pro

FTDI BASIC

The FTDI Basic connector is used only when the board is not populated with its own FT232R chip. The pin-out is compatible with the Sparkfun FTDI Basic Break out programming dongle.

Physical Layout

 

Board, Schematic and CAD FILES

See the Downloads Directory