**Designing a Retro Nixie Clock**
I recently embarked on a project to create a retro-style Nixie clock, and I'm excited to share my journey with you. The first step was to design the PCB (Printed Circuit Board) layout, taking into account the positioning of the Nixie tubes next to each other at a defined distance, which I had figured out beforehand. I then defined a size for the outline of the PCB and started arranging the remaining components around the tubes.
**Special Considerations**
Two special things about this PCB design are worth noting. Firstly, most of the components were positioned on the back side in order to save space on the top side, allowing the housing to easily close later. Secondly, I had to increase the clearance of the ground copper layer due to the high voltage.
**PCB Design Completion and Ordering**
Once my PCB design was complete, I ordered 10 PCBs with a black solder mask and an eco surface finish from JLC PCB at a relatively low price. After waiting for a week, the quality of the PCBs was certainly impressive, and it was time to start assembling the components.
**Component Assembly**
The first step in assembly was to solder all the SMD (Surface Mount Device) components followed by the 5V regulator and 16-pin IC. I then soloed male headers to the Arduino Pro Mini and pushed them into the PCB, making sure everything was securely in place. Later, I repeated the same procedure for the RTC breakout boards.
**Nixie Tube Assembly**
The Nixie tube assembly was the most challenging part of the project. My tactic was to shorten all the pins, remove the sockets, hot glue it in place right above the solder points, push the Nixie tube in place with a lot of patience, solder the pins, and then remove the hot glue. After adding all the remaining components, the electronics for the clock were complete.
**Testing and Programming**
I hooked up 12V, ground, and 170V for testing and connected an FTDI breakout to the Arduino to program it. I created a simple function that allowed me to display a different number on each display as a first test. However, I soon noticed a few problems.
**Problem-Solving**
The first problem was that the numbers were counting down instead of up, which was due to a layout error in the driver IC's output connections. To fix this, I simply reversed the numbering inside my created function. The next problem was that the next tube could only display uneven numbers, which according to the truth table, could be a problem with input A (aka pin 11). It turned out that for some reason, pin 11 of the Arduino was not able to properly pull the input of the driver IC. To fix this, I hooked up a 2710 ohm pulldown resistor to the pin.
**Final Assembly and Enclosure**
With those problems solved, I uploaded the ds1:03:07 test sketch from the Magic Designs ds1:03:07 library to the Arduino in order to use the serial monitor to set the time of the RTC. All I had to do was include this library in my code and add a few more lines to read the time and display it.
**Enclosure Design**
It was time for me to design a proper enclosure for my Nixie clock using 1-2-3D design software, with the help of a wood filament 3D printer. I designed not only the lids with cutouts for the tubes but also the main enclosure after drilling a hole in it to later glue a DC input jack in place.
**Final Assembly and Completion**
I connected all the components to one another with wire, secured the power supply to the bottom with M2.5 bolts, pushed the main PCB in place, and closed the door up with the lids, which I secured in place with M3 bolts. And just like that, my retro Nixie clock was complete.
I hope you enjoyed watching my journey of creating this project. If so, don't forget to Like, share, subscribe, and hit the notification bubble. Stay creative, and I will see you next time!