Many electronics projects begin with a clear idea: a sensor that reports temperature to a phone, a controller for a small machine, or a device for a research or education project. This article describes the typical stages between that idea and a working prototype, and what to prepare for each one.
Stage 1: Write down what the device must do
Before choosing parts, we agree on requirements in plain language. Useful questions include:
- What should the device measure, control or display?
- How is it powered: wall adapter, USB or battery? If battery, how long should it last?
- Does it need to connect to Wi-Fi, Bluetooth or a phone app?
- Where will it be used: indoors, outdoors, in heat or moisture?
- Roughly how many units might you need later?
Technical answers are not required at this stage. A clear description of the problem and the intended result is sufficient to begin.
Stage 2: Proof of concept
A proof of concept answers one question: can this work at all? It is usually built on a development board, such as an ESP32 or Arduino, with sensors and parts connected on a breadboard. These early builds are intentionally simple. The goal is to test the risky parts early, such as sensor accuracy, wireless range or battery life, before spending money on custom boards.
Stage 3: Circuit design
Once the concept works, the circuit is drawn as a schematic, which shows every component and how they connect. This is also when parts are chosen for real: available in stock, reasonably priced and suitable for the power and temperature conditions. Tools such as KiCad are commonly used for this step.
Stage 4: PCB layout
The schematic becomes a printed circuit board (PCB) layout: the physical shape of the board, where each part sits, and the copper traces between them. Layout affects size, heat, wireless performance and how easy the board is to assemble and fix. The design files are then sent to a board manufacturer.
Stage 5: Assembly and bring-up
When the boards arrive, components are assembled by hand or by an assembly service. "Bring-up" means powering the board carefully for the first time and checking it step by step: power supply first, then the microcontroller, then each sensor and connection.
Stage 6: Testing and revisions
The prototype is tested against the requirements from Stage 1. Expect to find things to improve: a connector in an awkward place, a sensor that needs filtering, or battery life that falls short. Fixes go into a second board revision. Planning for at least two revisions keeps the schedule realistic.
What affects time and cost
- Component availability. Some parts are out of stock or have long lead times.
- Board manufacturing and shipping time, which can range from days to weeks depending on the service.
- Number of revisions needed to meet the requirements.
- Enclosures. A 3D-printed or custom case is a separate design step.
- Firmware and app work. Software for the device and any companion app or dashboard.
What a prototype is not
A working prototype shows that the design works. It is not a product ready to sell. Selling electronics often requires compliance testing, for example for radio emissions or electrical safety, done by accredited labs. Plan for this separately if you intend to sell the device. We will tell you early if your project is likely to need it, design with those requirements in mind and prepare documentation that makes the lab's work easier.
How to prepare
- A one-page description of the problem and the ideal result.
- Photos or sketches, even rough ones.
- Any examples of similar products you like or dislike.
- Your timeline and an approximate budget range.
Ready to talk through an idea? Start here, or read more about our product design, prototyping and IoT work.