Prototype board module for the Sudoku solver

In my last post on the Sudoku solver, I mentioned I am building a prototype board intended for wire wrapping – one which I could use to test out my software and circuit diagram before ordering PCBs from a fab house.

… and sadly – it was a bust!

First of all, even before starting to put the board together, I knew it might cost me more to go that route than instead making a PCB layout of the circuit diagram and ordering the PCBs. But I still wanted to wire wrap the connections as opposed to using a protoboard (the later one felt, I don’t know – awkward and cumbersome?).

But with my current geo-location and conditions we live in at the moment with the C-19 pandemic, I knew that from the time I order to the time I receive the PCBs, I would wire wrap the entire board.

The thing is, I don’t have a wire wrap tool and wire either. Ordering and receiving that would take ages as well.

But I could still borrow one, right? 🙂

So… I first laid out everything, soldering wires for the programming header only and this was the result:

I then borrowed the tool and some wrapping wire only to realize the head of the bloody tool was big. Way bigger than the pitch between the holes on the perfboard (100mils or 2.54mm). C7@p!!

There was no way I could wire wrap with that! I quickly searched an interesting post on Instructables, and tried replicating the same. I like the idea, but me personal experience tells me – it ain’t working! … and once you try replicating the tool on your own, you soon realize why!?

But the antenna segment I picked was wider in diameter than the diameter of my pin plus the wire around it, resulting in little – to no friction between the “tool” and the wire – essentially twisting the wire itself around the “tool” rather than the pin!

Then I took the smallest/narrowest antenna segment with an inner diameter of roughly the pin plus the wire combined and attempted to wire wrap two pins before I waste the time of gluing the segment to the body of a pen (thus mimicking a tool screwdriver :)). But the twisting force and the crudeness of the “tool”itself, kept snapping the wire – although with occasional successful attempts.

For comparison, have a look at the real tool and the two antenna segments I used:

My final decision: I am planning on buying this tool and some spools of of wire, and still try to wire wrap the board. If it works, great – I can do my tests. If not, I will make my PCB layout and order PCBs with components from an online fab house and work on the “real deal”.

Hopefully, I will not introduce any errors (like the couple I’ve found and corrected already!) and/or screw up my routing!?