exixe: Low-cost miniature Nixie tube driver modules
exixe is a low-cost miniature driver module for IN-12 and IN-14 Nixie tubes.
Instead of using obscure out-of-production driver chips, it uses a STM32 to handle display and dimming of all digits with hardware PWM. The module is controlled via standard SPI protocol, and has onboard RGB LED backlight.
exixe is cheap, small and modular for easy integration. It is compatible with Arduino, Raspberry Pi, ESP8266, and virtually all embedded dev boards today.
Since each tube has its own driver, there is no need for multiplexing. Thus reducing the power consumption, simplifying the circuit design, increases perceived brightness, and prolongs the tube life.
Video
Here's a short video of exixe14 modules in action on the high precision clock shown in the above picture:
https://www.youtube.com/watch?v=r3d2alzgjKc
Features
Compared to the traditional approach, exixe modules offers significant advantages:
Small and modular
- 2x4 cm (0.79x1.57 inches)
- Breadboard friendly
- Easy integration
Low-cost
- $3 in components
- No need for expensive obscure vintage driver chips
SPI interface
- High speed, up to 24MHz SCLK
- Available on virtually all embedded systems including Arduino and Raspberry Pi
- Simple 16-byte command packet
Advanced control
- Powered by ARM Cortex-M0 microcontroller
- Hardware PWM on all cathodes and LEDs for smooth dimming and animations
Tube overdrive
- Optionally allows twice the cathode current
- For poisoned cathodes in second-hand tubes
RGB backlight
- Because RGB
No multiplexing
- Brighter display
- Longer tube life
- Simpler design
- Less power consumption
Pinout, SPI command format and technical details
Please see technical_details.md
Getting started
Please see getting_started.md
Buying some
I can custom make some exixe modules for you in small quantities. However, soldering them together and testing them takes a long time, so it's going to be more expensive than just the cost of materials.
As for a larger scale, I don't have plans of putting it in production right now, however I might consider a small run if there is enough interest.
Also, I do have some extra empty PCBs in panels of 8, so if you want I can sell one to you. You still need to source the rest of the components and solder it together though.
Email me at dekunukem gmail com for inquires.
Making Some
Full BOM here: exixe12, exixe14
- The NPN transistor used on every cathode is BF820
- The single PNP transistor used in overdrive circuit is MSB92
- Microcontroller is STM32F042K6T6
- LED is Wurth Electronics 150141M173100
Making some exixe modules yourself is fairly straightforward, just order the PCBs and parts and solder them together. Since the component count is not small and they are densely populated, I suggest order the PCB in panels of 6 or 8 and get a matching stencil to apply the paste. Use of reflow oven or skillet reflow is also recommended, since soldering each and every component by hand is basically torture.