I prototyped a small device named one knob and two keys. The idea is pretty simple, most of time in the “Read” mode, you can use the knob to scroll the page up and down. And it can have couple of other modes. For instance, in the “Media” mode, you can use the knob to turn the volume up and down.
As usual, I started with a breadboard as a typical Arduino project (left on the left), except I used Pro Micro chip, which is a relative small size and cheaper price comparing to an Arduino board. I also applied some soldering to it so that it can have some nice touch to the look.
But after playing with it for quite a few weeks, I felt it’s a bit bulky as you can see all the wires attached to it, therefore I spent some time and turned it into a PCB board prototype (right on the picture). It’s definitely far from industry ready, would be nice if it had a case to cover it, but at least now I can carry it to some other places with no worry to break the prototype. Since now I have done both versions, I’d like to share the experience, especially I’d like to comment on the differences.
Breadboard vs PCB
No matter whether you are new or experienced, the breadboard offers lots of benefits. It’s super easy to use, you don’t need any soldering experience. Just need a wire with two ends, one end plugged into a board pin, and another end to a breadboard slot. Wola, you can flash a light under second. It also make each row of the board to be connected, therefore giving you plenty of space to work with your plan without too much planning.
Practically, it’s really quick to amend your plan, which means it’s no brainer to debug your code or board. It’s matter of trial and error. If one way isn’t working, just keep trying until you find the right way. You don’t overthink too much details before starting to launch your plan.
The downside of breadboard come along the board as well. Because the board is bulky, your finished project normally won’t be any small in size. You can use short wires and clean ways to organize wires, but no matter how clean you are, it can be still messy in the end due to over tangling of the wires.
PCB is almost opposite of the breadboard. The size can be drastically reduced because we solder the wire directly to the electronic components, which means there’s no plug and play any more. You need to plan the location of the component as well as the wires in between. You need to gain some level of soldering experience because otherwise you won’t be able to get some component to the right place. This is also some time consuming part of the work. Moreover if you ever make a mistake, it can take you a while to figure out which part is wrong because trial and error approach isn’t available any more. You probably have to think of how to debug before doing it.
When everything is working out, PCB board can give you a product thrill, such as allowing you to take your piece wherever you want to. And if you know how to do woodwork, metal work, or plate work whatever, you might be able to polish it up to look really commercially useful.
What do I learn from them?
Now I have attempted both a little bit, I think PCB version is probably the next step in prototype after the breadboard version, especially in terms of the functionality. If you want to implement a feature, spending as much time as possible on the breadboard is more worthwhile, IMHO. Because it can save you tons of development and debugging time, this way you can focus more on the writing and testing the firmware. There’s just too much fun in there considering every idea can be fulfilled in a relatively cheaper way.
Once you are settled with your idea, your firmware has been tested thoroughly and you really want to pack them into a compact unit so you can play as a gadget, this is the time to consider a PCB version. The adventure can be a lot more diverse from there, because you will be facing the design question all the time, where do I put this and that, and how do I make it feel more user friendly. Of course not to mention, to put each idea to work, it might cost you more.
