Hardware Development Guide — The Design Phase

So you’ve made the commitment to get your hardware project off the ground. You’re ready to hire a design company to get your first prototype off the napkin and into your hands — but what do you do next?

Chances are you’ve chosen to invest in rapid prototyping because it allows you to create tangible products from your computer-aided (CAD) files, as opposed to just 2D drawings, with a relatively quick turnaround time.

This guide covers the first part of the rapid prototyping process — the design phase. You’ll learn about each of the steps involved in designing your hardware prototype so you’ll know exactly what to expect once you begin.

The major points we’ll cover include:

  • The product requirements document (PRD)
  • The four prototype components and the process for creating each one
  • Planning your project budget and timeline accordingly

As I detailed in “Ten Rules to Take Your Hardware Product From Concept to Market,” (I totally recommended reading it, by the way) these tips are based on a decade of creating hardware, including my own prototypes, and seven years of working with entrepreneurs to create their prototypes with my hardware design company, Jaycon.

With that said, I’m happy to share my experience with you so you can enjoy success with your own prototype!

Product Requirements Document

Many customers come to me and ask me to “ballpark” the cost of their project by briefly telling me about their idea. The reality is that product design companies work with all sorts of projects — simple and complex. Because no two projects are alike, a detailed product requirements document (PRD) is required to get the process started — and, of course, to even get a quote.

The PRD is one of the items discussed in my “Ten Rules” article and will be used every step of the way in the rapid prototyping process. It sets the tone for how your product will be designed and manufactured. I like to think of it as a list of the non-negotiables of your product. It’s in the PRD that you’ll include the following:

  • Your main product application — where it’ll be used, how and by whom
  • The minimum or maximum size you’d like your product to be
  • How long your battery should last (think of the use cases for your product)
  • Whether or not it should be waterproof, weather resistant, fireproof, etc.
  • Accuracy of any feature you may have (remember, the more accurate you want something to perform, the more expensive it gets)
  • Any integrations — how it should work with other systems

Let’s say you’re trying to make a smartwatch. A lot of time will be spent picking parts with a lower power consumption and optimizing it for a longer battery life. For a device like an Amazon Echo, on the other hand, you wouldn’t really be concerned with battery life since you have to plug it into the wall. These are the types of items that should be well documented in your PRD.

A design company, such as Jaycon, will gather the information in your PRD and start designing your product around these constraints — along with what will be realistic based on your budget and available technologies. They’ll take the information in your PRD and make into a statement of work (SOW), which will outline project-specific activities, timelines, deliverables and other payment-related information.

The last important thing in the PRD is that it’ll cover each of the four components of your prototype, which you’ll read about next.

The Four Components of a Typical Hardware Prototype

Most hardware products we design usually consist of four different parts:

  1. An enclosure made of plastic, metal or another material
  2. A printed circuit board or other electronic components
  3. Firmware, or the code that runs on the electronic device
  4. Software, or the code that runs on the computer or phone to interact with your newly developed hardware

However, prototypes don’t always have all of these parts (see example below). For instance, an iPhone case would only have a plastic component and none of the others would matter. Or maybe you are just trying to launch an educational development kit (such as the Arduino), so you don’t really need a case or software.

Not all hardware products have a circuit board or an enclosure.

First Component: The Enclosure

The hardware enclosure design is usually a two-step process.

Industrial design sketches are provided to the client to help guide the direction of the product’s aesthetics.

The first step is to have the design company’s industrial designer sketch out several different concepts of what the product could look like based on what it’ll be used for. The sketch is often done by hand but some industrial designers use software.

Several sketches may be required in order to ensure that the hardware enclosure not only meets your vision but is feasible for manufacturing. We usually do four or five sketches to gather feedback before settling on something the customer really wants.

If a customer is still in the initial steps of product development and only wants a minimum viable product (MVP) or a rough prototype to analyze its use cases, we may skip refining the drawing and just work from an initial sketch. At this point, functionality is more important than aesthetics and adding industrial design to the mix would just be more costly and lengthy for someone who just wants it for testing purposes.

The mechanical engineer then takes the industrial design sketches and 3D models them in a CAD software program, making any needed modifications to ensure the design is manufacturable.

After the sketch is finalized, a CAD designer will create a model for the prototype using software such as SolidWorks, AutoCAD Inventor, Pro Engineer or Catia. It’s in this step that the engineer will specify tolerances, fittings, assemblies, DFM (design for manufacturability) features, etc. The 3D drawings usually take a lot of time to model. It can take two to three weeks or several months depending on the complexity of the product.

The end result will be a set of different types of files usually composed of 3D CAD files, 2D drawings for manufacturing, and any BOM for off-the-shelf parts that go into the product. The actual 3D printing or CNC of your prototype, based on these files, will happen after the design phase is complete and the next phase begins.

Want to see what an injection molding optimized file looks like? I made our popular injection molding pencil holder files available for download here.

Second Component: The Circuit Board

The design of the circuit board, or the brains of your product, also often follows a two-step process.

The first step is the research and development of your product. Some of the products we work on are very innovative and have never been done before. That means it’s hard for us to estimate how long it would take to prove out the concept before trying to design it.

Example of a POC

The second step is a proof of concept (POC). Working in uncharted territory usually results in a proof of concept that will test your product’s function and technology — but it’ll look nothing like the final product as we’ll most likely use breadboards and off-the-shelf electronic parts. The POC's only purpose is to make sure that your product idea is doable using what is technologically feasible at the present moment. We’ll use breadboards, microcontrollers, sensors, jumper wires and other electronic components in order to get a POC.

Yet, a lot of our products skip the POC if the product involves technology we know will work. If that’s the case, we’ll usually jump straight to the circuit board design.

It’s almost always a good idea to do the circuit board design in tandem with the enclosure design, unless your product does not have an enclosure.

After the POC (on the left) is completed, the electrical engineer has to design the PCB (printed circuit board) in conjunction with the design of the case (on the right) to ensure proper fitting.

Unlike the enclosure design process, however, the circuit board design normally takes longer to make once the first design is ready. This is because the circuit board prototyping process is very slow. Not only do we have make a POC, but once it’s done we have to design the PCB on the computer, make the bare circuit board, create a stencil for the board and order all the components before you can actually assemble the final preproduction prototype and test to ensure the design worked.

It’s not like we can just go to a 3D printer and hit “print.” Every time we have an error we need to address, we have to make a new version, make a new bare board, populate it, program it, test it, rinse and repeat. This process can take between one and three months.

Tip: If you’re creating your own prototype or want to test out a concept, there are many great tools available to design your own circuit board, including Altium, Eagle and KiCad.

At the end of the circuit board design stage, we end up with a Gerber File that shows the schematics of the board and a Bill of Materials with the components that will be populated into the board. Most of the time we also deliver one finished, assembled prototype that the customer can now test in its environment before going into production or making changes.

See for yourself what type of files we generate for the PCB portion of a hardware product. I made the folder available here.

Third Component: Firmware

Firmware is software that gives your product life. To design it, we basically have to convert your product requirements into code.

For example, if you want a blue light to come on when your device is connected, we need to program that feature. Turning on an LED is easy, but add 50 other things that need to happen in a multitude of scenarios, and you may run into some pretty complex problems. And most programmers will know that these firmware design problems can take forever to figure out.

Estimate several months if not a year to work out all your firmware issues.

Tip: If you are just getting into the electronics space, I’d recommend getting an Arduino Starter Kit and working through some of the examples you will find online. Within a couple of weeks, you can build your understanding of how this stuff really works. It’ll help you understand your product better and give you the ability to request more enhanced features.

Programming is not for everyone but if you think you can work through it, it’s totally worth the effort. We usually program everything in C but have also written in C++, Python and many other languages. If you’re interested in learning more advanced languages, I’d definitely recommend a Raspberry Pi kit.

Fourth Component: Software

The last part of many modern hardware products is the software, a program that allows your hardware to send and receive data over a connection while displaying it to you in a usable way.

This is usually a program that runs on your computer — or on the web — or an application that runs on your phone. Fitbit, for example, uses a wristband with a microcontroller, accelerometer and battery to send your step count to your phone. The application on your phone converts this data into useful information. You can also use the application to configure how often the band reports information to the phone to conserve battery life.

Example hardware-controlled dashboard design by by Gururaj

Not all products require a software application to work — think of a Bluetooth speaker. If that’s the case, you’d only need firmware development.

You’ll probably spend even more on software development than you would on firmware development, mostly due to user interface (UI) and user experience (UX) design. Although they may bring hefty costs, investing in UI/UX will certainly help your application in being more effective, user-friendly and aesthetically pleasing — especially if the software is the part where your customers will interact with your product the most.

Keep in mind that software and firmware developers command a very high salary. Expect this part to be the largest part of your hardware product design budget. An average application can cost anywhere from $10,000 to $100,000.

Budgeting for Hardware Product Design

Now comes the most asked question: how much should you budget for your hardware prototype design?

The answer is, it depends.

I love this video below of a Spider-Man drawing done in 10 minutes, five minutes, and 10 seconds. Product design companies can do the same thing when it comes to hardware product design — but of course, many of them, like Jaycon, don’t work with unrealistic budgets. Making a world-class work of art from a 10-second Spider-Man drawing would be a lofty goal. Frankly, we’re proud of our work and strive to keep it that way.

Let’s say you wanted to design an alarm clock. You could spend $25,000, $50,000 or $100,000 for the full product design. All of these would get you an alarm clock prototype, but the difference between them would be the Earth and moon apart.

In the end, the more funding you have for rapid prototyping, the more engineering time you can spend on it and the better the product can get.

With that said, don’t be afraid to share your prototyping budget with your design team. They can help you optimize it to get the best results.

And remember, if you have any questions about bringing your hardware idea to life, don’t hesitate to add me on LinkedIn. I’m always eager to learn about entrepreneur’s experiences. You can also feel free to comment below to share your thoughts or questions with readers who might’ve had similar experiences.

Hardware Product Design Takeaways

In conclusion, here some major takeaways about the hardware design phase.

Steps involved in hardware product design (some may overlap):

  1. Creation of a product requirements document (PRD)
  2. Enclosure design
  3. Circuit board design
  4. Firmware development
  5. Software development

Total average time for design: Three months to a year

Total average budget for design: $25,000-$100,000


  • Design files for the enclosure
  • Design files for the circuit board
  • Firmware documentation and source code
  • Software documentation and source code

About the Author

Hi, I’m Jay, the founder of Jaycon Systems. I’ve been developing hardware ever since I can remember and love learning about disruptive technologies. In my blog I share with you tips on building great hardware products; my take on new disruptive technologies; and other random & relevant thoughts about tech and entrepreneurship. If you like my posts, don’t be shy — give it a nice round of applause and add me on LinkedIn, I’d love to connect with you.