Hello world! Ever wondered how those beautiful Nixie tube clock that light up with the digits of the time like something out of an old world magical movie is made? Well, today let’s learn all about it and make one of our own.
So what we’re making today can be described as an Arduino based nixie clock that runs on a break out board, voltage set up the chip, Arduino uno and 14 in nixie tubes. Come and see how to make one within a budget (Although you could spend as much as you can to get it to look as good as you want 😊 ) !
These are Material Required to build the project.
- A PCB of your choice to solder everything on
- Arduino Uno
- Arduino Uno Prototype shield
- ds1307 clock breakout board
- 6 numbers of .1 uF capacitors
- 6 numbers of 15K resistors
- 6 numbers of Nixie Tube Drive IC Chip
- 6 numbers14 in Nixie Tube
- 3 numbers of Shift Register IC Chip
- 12V DC 2.5 amp power supply
- Voltage Step Up Chip
- On/Off toggle switch
- 16 pin IC socket (qty 9)
- Electrical connectors
Step 1: Gather all the materials required
Now that we have all the components required, let’s Set up the wall outlet. To set up the particular wall outlet that we mentioned in our list. First, we get the too bare wire from the outlet. Take one of the female multiple tail ends and cut off one of the female ends close to the end of the base. Now we can observe 2 wires inside the single black insulation, one red and the other black. The black wire is the ground wire(GND) and the red wire is the live(or hot) wire. Remove the Initial black insulation of the wire at least 2 inches to get the red and black wires and after that, we can remove the insulation from the red and black wires and get the copper strands about half an inch in length.
Add a connector to the two ends of the power supply and then cut off the 2 lengths of the solid core wire, preferably, the red and the black wires. Cut the length of each of red and black wires at least 5 inches and remove the insulation at both ends. Add another wire connector that will attach to the wire connector at the end of the wall power supply and one end of the core wire. Now, connect the 2 wire connectors to get a solid core end for both live and ground wires. The other end will be used later so keep the insulation removed.
Add electrical tape (or heat shrink) around each wire connection to avoid any metal on metal contact after the wires are connected. This step is pretty much left to your convenience in selecting between the electrical tape or heat shrink or even soldering the wires into the wire connectors, based on how important the look of the project is to you.
Now, we have to set up the Step up chip. The step up chip we’re using has an input and an output terminal, we have to solder the parts onto the PCB. Add power to the chip’s input and measure the output on a multimeter. Increase or decrease the output voltage using a block on the step up chip. Use the wall power supply since this is what will be used finally on the clock.
Step 2: Use the wall power supply.
- Cut off a female end right at the base from the part of the wall supply that has multiple ends. Remove the black insulation. Now we can see two wires, one black, which is the ground wire and another red which is the live(or hot) wire. Remove the insulation from both ends of each wire so that the copper wires can be used.
- Attach an electrical connector to each end of the bare metal. I prefer shovels and clip style connectors that must be crimped onto the wire. Add solder to where the copper wire meets the electrical connector. Attach an electrical connector to both the hot and ground wire.
- Get two pieces of solid core wire. Use red and black wires so that it matches the wires in the wall power supply. Remove a little bit of insulation at each end to expose bare metal. Attach an electrical connector to one end of each of our two wires. Solder each connector for better surface contact. Also, attach an electrical connector that will connect to the connectors we used on the wall power supply.
- After we have the electrical connectors on both the wires on the wall power supply as well as the two solid core wires, plug them in. ensure that you have good contact between the connectors by checking on a multimeter.
- Now let’s Plug our wall power supply into an outlet after we have everything connected. Ensure that the red and the black wires don’t touch at all or we could end up with a short circuit, which will not be redeemable. Check if the wall outlet power supply is always on 12 volts.
- Now that we have a solid 12 volts DC current coming from the wall power supply, use electrical tape(or heat shrink) to first tape each individual connection, one for the hot wire and one for the ground wire, and then tape both of the taped portions together.
- Plug the wall power supply into your step up chip. The input side of the step up chip will be marked with a “GND” or ground, and a hot wire input. Plug each wire into their respective terminal spot. It could be trouble if you mix it up since the input and output voltages vary highly.
- For this step, we will need to have someone hold the probes of the multi-meter on the output terminal to get a reading the voltage coming out of the step up chip. Adjust the output voltage by using a small screw driver to turn the variable block on the step up chip. Get an output voltage of about 178V – 182V. Once this is done, our step up chip is ready.
Let’s use a variable power supply or bench supply next
If you have a variable power supply, set it up to 12 volts and set the amps to a minimum that will allow 12 volts. Connect the ground and hot wire to the corresponding terminals that are marked as the 12 volt input, and then measure the output voltage. Set the terminal block to the required output voltage. Preferably around 178 volts.
Now that we have the step up chip set to the required voltage, we are ready to begin testing our tubes individually.
Step 3: Testing Each Individual Nixie Tube
It’s obviously a good idea to test individual legs of the nixie tube so that we know it’s working faultlessly. There are several explanatory websites and videos on the internet for doing so. Check one out to test all the digits.
Step 4: Building and Testing a Dual Tube Circuit
Using LEDs’ instead of the actual nixie tube to remove the power supply and tube portions of the circuit will help to troubleshoot easier. Since we are running a circuit with two 74141 chips we need 10 LEDs’ to test the circuit.
Follow the given circuit diagram to create a circuit and replace the nixie tube cathodes with LEDs’. Connect the individual pin of the 7414 pin leg which displays a nixie tube digit to a ground leg of the LED. Connect the other leg of the LED to the power bar on the breadboard. Follow the schematic and attach the shift register to the 74141 IC chip. Perform a trial to see if it is possible to count from 0 to 9 without much delay. If the trial is successful and the tubes are functioning properly, then we can introduce the ds1307 time breakout board to make each time unit appear. We can use the 3 Arduino inputs to switch between seconds, minutes, and hours.
Step 5: Ds1307 Breakout
Copy and paste bits of code from the Arduino sketch ds1307 into a new sketch and then use the comm port to see if we get the time to be displayed correctly. Once this is achieved, we can move on to the next step.
Step 6: Running One Set of Nixie Tubes With the DS1307
Now let’s discuss using the DS1307 to convert each digit into a digit on each tube. We can use nixie tubes or LEDs depending on our ease to use them. The code will be the focus on this step. We need to use code to convert the time from the DS1307 breakout board to read each time digit and display it on the tube. Considering each set of tubes will use 3 output pins from the Arduino, the best way is to have 3 output pins beside each other for each unit of time.
It is important to notice that the tubes will go through anti-poisoning cycles at certain Intervals, that is, a particular digit being on for extended periods of, without using the rest of the digits, can cause damage to the tube. This is applicable in particular to the digit on the tens place if we are to use military time since it needs to accommodate only 3 digits to cover 24 hours.
Since this tube changes twice or so within 24 hours, the best idea would be to cycle the tube at intervals to increase its longevity. We could use intervals to do some cools stuff limited only by our creativity. The important thing to know is that it is essential for the code that you come up with, has to include these cycles through all the digits of the tube. One such example is to count each tube from 9 and inducing a delay of a few seconds. Again, this is only one of many possible solutions.
If we were to come up with a good idea to test this, plugging the individual sets of tubes into outputs of each set of tubes into the Arduino to test the time unit would be ideal. This way we can ensure each of them works and get ready for the final assembly.
Step 7:Final Assembly
Now that we have all of the time units working, we can move onto assembling. This step can be complicated or easy depending on how some of the necessary steps are performed. As always, we’re taking the easiest steps.
1. Soldering Up The Prototype Shield:
The prototype shield for the Arduino uno is the most important factor in this step. We can run all of your 5v logic and ground using a GND and 5V row on the prototype shield. Solder in pin headers (female) and stick the 5V and GND wires into them.
For the high voltage wire, we will solder in 4 pinheads and a row of 5 pinheads for the high voltage ground. We need to tie all the pinheads together with the solder on the bottom of the protoboard.
Finally, we need to add the DS-1307 breakout boards to pins A2 to A5. Point the breakout board into the protoboard and leave the last pin not inserted into anything.
2. Dual Tube Circuits to Arduino:
At this point in the building we’ll have three circuits with two tubes on each, Each circuit having
- 2 anode resistors for the tubes
- 2 Nixie Tubes
- 2 IC chips to run each tube (74141 chip)
- 1 shift register running the two 74141 IC chips
Also, we’ll have the following inputs:
- 1 high voltage positive wire
- 1 high voltage ground wire
- 1 red 5v logic wire
- 1 black 5v logic ground wire
- 3 other wires that are used to control the shift register.
Plug in the high voltage red wires to the row of female headers we soldered on to the protoboard. Plug in the high voltage ground wires to the female headers we soldered into the protoboard. Plug in the 5v red logic wires to the proto board. Plug in the 5v ground wires to the soldered on female headers.
Finally, plug in the data wires that control the shift register. Arduino digital pins 2, 3, and 4 will control the seconds. Arduino digital pins 5, 6, and 7 will control the hours’ circuit. Arduino digital pins 8, 9, and 10 will control the minutes.
3. On/Off switch
Now we have to wire in the on/off switch. The easiest way to do so is as follows:
Run the on/off switch between the wall power supply and the step up chip. The idea here is the Arduino stays on all the time and we can turn the tubes on and off. If the components were to go bad, the tubes will most probably take the fall. This will keep the battery of the DS-1307 alive longer and maximize the time it would work functionally without any maintenance.
4. Power Supply:
Hook up the external wall power supply. This can be done by splitting the end of the wall supply at two points, leaving us with two sets of red and black wire at 12 volts. Run one set of wires ( a red and black one) to the voltage step up chip, and another set to the Arduino board. Plug the red (12V wire) into the Vin of the Arduino board and the black wire (GND) into the GND pin on the Arduino shield.
Step 8: Case and Completion
If you’ve followed through all the steps, congratulations!! You’re now in possession of a fully functional Arduino nixie clock. Celebrate this moment with building yours own custom case. We’d like to leave some important things to remember while doing so. Most importantly, LEAVE ROOM. This is important for multiple reasons. One of which being, the wires could go haywire and drive you insane in a confined space. Also, you never know when inspiration strikes to add to this wonderful project. And finally, the most important thing of all, Check some cools ideas online.