From dev board to custom PCB: what changes and what to prepare
What happens when an ESP32, Arduino or Raspberry Pi prototype becomes a real product, and what to have ready before you hire an engineer.
A dev-board prototype is the fastest way to prove an idea. It is also full of things a product cannot have: a USB cable for power, a programmer on the board, headers, jumper wires, and components chosen because a tutorial used them. Moving to a custom PCB replaces all of that with a circuit designed for your product.
What changes
Power
Dev boards run from USB and waste power on LEDs, regulators and USB bridges that sit idle. A product usually runs from a battery or an external supply, needs protection against reverse connection and surges, and has to sleep at microamps. The power design is often the largest change.
Radio
If your prototype uses Wi-Fi or Bluetooth, keep a pre-certified module on the first custom board. It keeps the radio certification of the module valid for your product (subject to the module's conditions) and lets you focus on everything else. The antenna area needs a clear zone free of copper, metal and batteries.
Programming and debugging
The on-board programmer disappears. The custom board gets a small debug connector or test pads, and a production programming method.
Robustness
Every connector that a user can touch needs ESD protection. Inputs need defined behaviour when unplugged. The board needs to survive the temperature range where it will live.
Cost and supply
Each part is chosen for price at your volume, availability at two distributors and a lifecycle that outlasts the product.
What stays
Your application logic, your sensors if they were chosen well, and most of your firmware above the driver layer. A good transition keeps the same microcontroller family so the software carries over with minimal changes.
What to prepare before you hire an engineer
- A list of every module, sensor and dev board in the prototype, with links.
- A wiring description or photos from several angles.
- The firmware source, and a note on which parts are yours and which are libraries.
- How the product is powered, where it is used, and how long it must run on a battery.
- Target size, number of units and cost per unit.
- What must not change, for example the app or the cloud protocol.
With that, a hardware engineer can quote a fixed price for schematic and layout without a single meeting.
Related questions
Can I keep using the ESP32 on my custom board?
Yes, and it is often the best choice for the first product revision. We usually keep a certified ESP32 module and redesign power, protection and connectors around it.
How long does it take to go from dev board to custom prototype?
Typically six to ten weeks for a medium-complexity board: two to four weeks of design, two to three weeks of fabrication and one to two weeks of bring-up.
Send us what you have. We tell you what it takes to finish it.
Answer five questions and see an indicative budget in two minutes. When you are ready, sign our NDA, upload your documentation and get a fixed quote. Everything by e-mail, with a call whenever you prefer.