2021/04/28

Go back in time with a Divergence Meter Nixie clock

Clocks are useful things, mostly they tell the time and this is generally a good thing.

Though we live in a digital age, people do have a thing for clocks, especially those that are worn on the wrist and these come in a multitude of varieties. These were analogue, then came the invention of the digital watch and then people spent a lot of money on analogue versions again.

Clocks (as in actual clocks) have tended to remain analogue, circular discs with hands that move around pointing to digits painted (or embossed) around the edge. Clocks can be powered with some clever electronics so they keep time accurately such as using a radio time signal.

Digital clocks to exist and they use flat displays such as e-ink, OLED or LCD. They tend not to be very pretty.

In the past, lots of devices used something called a Nixie display, they look like vacuum tubes, except rather than warming up they have a variety of cold cathodes inside, shaped to look like numbers or digits. They were popular in the 1960's but there has been a recent resurgence and a numeric variety the IN-14 is still available.

Nixie tubes are filled with low pressure neon (and sometimes some other gasses or mercury to change the colour) and when a voltage (around 200V) is applied, the cathode will glow. If the gas is neon based, it's usualy a nice orange glow.

Some enterprising Ukrainians have decided to design and build pretty clocks based on Nixie tubes. These come in several varieties and can be Arduino or Raspberry Pi based using IN-14 or IN-18 Nixie tubes and in kit form or preassembled. This review is on the Arduino Shield NCS314 IN-14 variety and has an external DS18B20 temperature sensor. It's also possible to connect an external GPS that uses NMEA protocol and the clock will maintain time, however the GPS unit does need to maintain visibility of the sky so may not be suitable for indoor use.

There are also RGB LEDs that illuminate the base of the Nixie tubes, but these can be distracting rather than adding aesthetics. This also uses the Arduino MEGA board which runs the software (all available on Github).

There is a mode button which switches between time, date and alarm mode (and up and down buttons to change settings). The LEDs are turned on and off by long pressing the down button and then using the up and down buttons to change the colour.

If you're into pretty old fashioned "digital" clocks, you cant go wrong with a Nixie clock (it is beautiful). The costs vary depending on what options are selected (with/without tubes, sockets, temp sensor, GPS, Arduino Uno/MEGA), but the version shown is about $170.00

No comments: