So I’ve been wanting to do this for a few years now, but I’ve never had the patience to really devote some time to it … Until now.

Rendering of partially designed board (top view)

I’ve been learning circuit board design and component selection. I’m hoping to not only simplify the entire wiring design for my cold brewer. I’m trying to expand its capabilities tenfold.

Bottom view of board concept

My core idea for my Designs has always been open source, community based. And I know my community right now is really quite small … But I figure, build it and they will come … to an extent.

It’s quite inspiring actually, that as consumers, we have the ability to affordably 3d print parts and design our own custom circuit boards in a small scale without owning any special equipment. These are actually two cornerstones of basically everything you can imagine. Add in some handy woodworking and some simple steel work and you can pretty much build anything!

I can go on and on about this, but this post is specifically about the skill of designing your own circuit board. I am not proficient at it, nor have I even fully completed a single prototype yet (currently in design stage). What I wanted to share is how satisfying the process actually is. Once you get over how daunting of a task it seems to be, you start to appreciate the “skill” part of the exercise.

I truly mean skill here. There are so many different methods and permutations to decide on, that your design truly is a work of art when you are finished with it. Working through the steps actually makes you appreciate others’ Designs that much more.

2 Layer routing details with all components

The starting point really is finding the right software. I did a little research and downloaded two: ExpressPCB and Eagle.

I was actually more hopeful of ExpressPCB with their software being more user friendly and much easier to get a quote and place your order.

But due to my favorite board distributer (Sparkfun) using Eagle and sharing all their Eagle files on the parts they sell, I decided to learn the more powerful and generally accepted Eagle.

After a few hours of playing with the Eagle software, I was able to get a general idea of how the software works. I managed to make a circuit diagram incorporating:

board mounted to servo structure

– header connections for the ESP32 (still my brains of the design)
– 2 servo headers (3 wire)
– 1 temperature sensor header (3 wire)
– 1 Peltier plate header (2 wire)
– 1 fan header (2 wire)
– 2 photo interrupters
– various capacitors, resistors and inductors to smooth and control the voltage
– 1 full h-bridge microchip (16pin) to control the Peltier plate, such an amperage hungry device

Now, to be fair, most of my time was actually spent deciding which parts to go with … Which chip … Etc.

After downloading the parts I wanted and custom making the chip on Eagle (not in the default library) … I was able to connect all the signals and then started working on the board design.

This is the part that feels good. When you start, this just looks like a rat’s nest of parts and wires. But the part when you start connecting components with the size constraints and wire crossing constraints is the fun part.

After you finish designing the board, you can use: 3d BRD Viewer (Webpage has been improved since I used it!)¬†to quickly view a render of your design. That’s where I got my renders.

To complete this post, I wanted to provide a proper update regarding the next design (shown above). I’m currently working on the mechanism (servos, boards, and valve). Shortly, I will be working on the coffee holder and then move onto the wire routing. There is still a long ways to go before I’m actually happy with my design.

Once this is complete, I’ll actually be able to use this design to retrograde update the “Personal” version. With this new design, I should be able to cut costs and add features as needed.

Stay tuned folks!