diy protoboard Shields and wire management

Date written and posted: 1/17/2020

While working on my capstone project last semester, I came across the issue of dealing with numerous solid core/jumper wires needing a secure but detachable connection to the solderless breadboard. At that point in the progress of our project, I was hesitant to fully commit to my wiring by soldering wires directly to the microcontroller (a Teensy 3.5, in this case) and I wanted the potential to reuse the microcontroller for future projects. So, I came up with this method of DIY protoboard shields to provide a more secure connection to the breadboard and spare the microcontroller from being soldered to directly.

I’m sure I’m not the first one who’s thought of this, but I found it quite useful and thought I’d share. It seems like it’d be one of those simple techniques that you’d pick up after a non-trivial amount of time building prototypes, so hopefully I will save you some time in that respect.

Pros: Can reuse microcontroller and other components, can make changes to wiring more easily/with less risk to the more expensive components, can swap out components

Cons: Requires more time, work, supplies/equipment

Supplies & Equipment:

  • Soldering iron & solder wire

  • Protoboards / solderable breadboards (same thing) - depending on your needs, either with or without connections between the vias

  • Solid core or male-male/male-female jumper wires

  • Male header pins (typically spaced 0.1” apart to fit standard breadboards)

  • Hacksaw or band saw

  • Sandpaper

  • Wire cutters/strippers (if using solid core wire)

  • Clamp (optional but very helpful)

Here’s a picture of the system I was working with:

On the right is a picture of just the switches going into the breadboard. The picture on the left shows all the wiring of the full system: 10 switches, one battery pack with two USB ports, two servo motors, and a stepper motor driver, complete with the DIY shields. In total, that’s 28 wires that need to be secured to this half-sized solderless breadboard for our system.

0. make a wiring schematic for your system

I would recommend this technique for an intermediate stage of your prototype, after you have planned out and tested all your wiring to make sure it works.

1. Select Appropriate Protoboard and Cut to size

I just used a hacksaw to cut the protoboards to the size that would fit on the breadboard. In the middle picture, I had already soldered the header pins to the breadboard but I wouldn’t recommend doing that before cutting.

Tips:

  • Don’t use too much force- trust in the sawing motion and serrated teeth. You can also use a bandsaw or even a scroll saw, but for smaller pieces I think it’s a bit safer to just do it manually.

  • Also don’t worry too much about making a perfectly straight cut, since you can always sand it down later. Just start your cut with enough distance from the holes you’re actually planning on using to account for this (for me, I started my cut 2-3 rows away from the ones I was planning on using).

  • On protoboard selection: you’ll notice that I used two different types of protoboards for my shields. The green one has holes that are conductive along the rows, like a standard breadboard without power rails. On the other hand, the section of the red protoboard that I used has holes that are conductive along the column, like the power rails of a standard breadboard. I found it helpful to mirror the breadboard structure when selecting which protoboards I would use.

2. Sand the protoboard and fit to the breadboard

Just grab some sandpaper (I used 80 grit) and sand down the edges so that they’re straight. Hold down the sandpaper to the table (or a flat surface) and then apply even pressure to the protoboard as you move it back and forth. This will help with making it even and it’s easier than keeping the protoboard fixed while moving the sandpaper. Check the fit with the breadboard and other protoboards as you go.

3. Solder wires and header pins to protoboards

Pretty self explanatory here- just solder the wires and header pins in a way that makes sense for the protoboard layout. I just soldered the wires in the row next to the header pins. In the first and third picture above, I didn’t cut the protoboard before soldering both the header pins and the wires, which I would not recommend.

Tips:

  • Use a breadboard for soldering and solder the header pins onto the protoboard before soldering the jumper/solid core wires. This will keep the protoboard stable and secure while you solder the jumper/solid core wires.

  • Label your wires (such as with blue tape) before soldering to the protoboard.

  • For the power rail, solder header pins both at the top and the bottom of the protoboard, for a total of four header pins. Although you only need two header pins for it to work, having four will add supports at both ends and increase stability.

  • For future improvement: The bits of uninsulated wire going into the protoboards are a little exposed for my liking (potential to short, although this was not what caused our Teensy to die), so either cut that shorter or consider heat shrink tubing for insulation.

  • You can also solder wires between the protoboard shields!

Bonus Wire management tip

For hobbyist servo motor wires that come in groups of 3, or really for any type of wiring that is more than 1 wire, I like to braid the wires together and use standard color coding to distinguish them. It really helps the wiring stay more organized and look polished, especially when there is more than 1 component (e.g. multiple servo motors, multiple sensors, etc.).

However, a situation when I would not use this strategy is when I have 1 wire coming from multiple of the same components. A nuance, for sure, but I think it would be a bad idea to do that since you’ll want to be able to easily trace each wire to its component for troubleshooting. For example, when I did the wiring for the switches (the large green protoboard with yellow, red, white, and turquoise wires), I did not intertwine the turquoise wires going to the breadboard, which definitely helped with troubleshooting. Of course, it would have been best for me to use different colored wires for each switch, but at the time I didn’t have that option.

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Final product

Peace of mind that any bugs or errors are highly unlikely to be caused by wires being unplugged, and the potential to frugally reuse the Teensy for future projects (we shorted it the night before the demo….but the potential was there!).