02 April 2017

Just ordered my first PCBs

After fiddling with KiCad for few month, reviewing the same circuit over and over again, I decided to stick with a relatively general purpose PCB for four ZM1332/NL5870S nixies. It is a multiplexed design that includes the decoder IC on-board (7441 or equivalent). Anodes must be multiplexed on the logic board since everyone has his preferred way of doing it (pnp, optoisolator, pmos).

This is the 3D render (by KiCad) of the boards I have ordered on firstpcb.com:
Since I was not satisfied with the result of the embedded autorouter I did it myself. I have never designed a 2-layer PCB, so I used this extra degree of freedom only when I was stuck. I ended up with only two vias, and other transitions were handled at pads when needed.
ZM1332 cold cathode displays are small and not too tall, so I put all components on the back side of the board, leaving only tubes on top. There are no overlapping components, so it won't matter which side I start soldering.
In order to simplify routing I have remapped the outputs of driver IC to actual digits, so this will have to be taken into account in the firmware. The two headers mantain a 0.1" spacing even if they are far apart.

I am really curious to see the resulting boards, and to build them of course! By the way, the size is 10x5 cm.

If all goes as planned, I will publish what is needed to reproduce this project. Fabricator emailed me they should ship on April 7th, 2017. No idea how long it will take to get here!

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