Your prototype runs on an Arduino, ESP32 or Raspberry Pi. What changes when you move to a custom PCB for production?

Moving a prototype from an Arduino, ESP32 or Raspberry Pi dev board to a production product changes almost everything around the chip. A development board quietly supplies a USB-to-serial chip, a regulator, the reset and boot circuit, protection parts and pin headers, and none of it is built for a commercial product: the board is too big for most cases, draws too much power when it's supposed to be asleep, and can't be programmed or tested quickly on a production line. For a first run of a few hundred to a few thousand units, the usual path is to keep the same chip family on a custom PCB shaped to fit your case, use a Wi-Fi or Bluetooth module that already holds FCC approval if the product has a radio, add test points and a programming connector for the factory, and turn the firmware into a production build that can be flashed, tested and updated. A product built on a Raspberry Pi usually moves to a Compute Module on a custom carrier board. Plan on two or three board revisions and about four to nine months.

What circuits does a dev board provide that your custom PCB has to include?

A dev board is built so anyone can plug it into a laptop and start. That convenience comes from parts you don't see: a USB-to-serial chip for flashing and the serial monitor, a regulator sized for USB power, a reset and boot circuit, a crystal with its load capacitors, pull-up resistors on the boot pins, and protection on the USB port. Newer chips such as the ESP32-S3, ESP32-C3 and RP2040 have USB built in, so a production board can drop the USB-to-serial chip and still be flashed over USB. A first custom board that gets the boot pins, the reset circuit or the crystal wrong often won't boot at all; with a module, the crystal and flash memory are already inside it. A practical first step: open the dev board's published schematic and decide, block by block, whether to keep it, replace it or drop it on purpose.

What changes from a dev board to a custom production PCB?

The table compares, area by area, what an Arduino, ESP32 or similar dev board provides and what a custom production PCB needs.

Area	On the dev board	On a production PCB	Why it matters
Size and shape	A fixed outline, often with stacked pin headers	An outline, mounting holes and connector, button and LED positions drawn together with the case	The board has to fit the case, and both are designed from one 3D model
Connections	Pin headers, breakout boards and jumper wires	Parts on one board, plus locking connectors where cables are needed	Loose wires fail when a product is dropped or shaken, and are slow to assemble
Power	A regulator sized for USB power	A regulator, battery charger and protection chosen for the product, with the sleep current measured	A dev board can draw about 10 mA "asleep" against a target near 10 µA, which turns months of battery life into days
Programming	A USB port and a USB-to-serial chip	A programming header or pads, with control of the boot and reset pins, or the chip's own USB	The factory still has to load firmware into every unit
Factory test	None	Test points on every power rail and key signal, reachable by spring pins (pogo pins), and a test mode in the firmware	Each unit gets flashed, tested and logged in a minute or two
Radio	A module or chip with its antenna wherever the dev board put it	A module at the board edge, with copper kept clear around the antenna and space between it and the case, battery and metal	Range can drop sharply once the board is inside the case
Protection	Protection on the USB port	Protection against static, reversed power and overcurrent wherever users touch or plug in	Missing protection shows up as random failures in the field
Firmware	A sketch built with whatever libraries were installed	A version-controlled build with a fixed toolchain, a watchdog, an update path and security settings	Any engineer can rebuild it, the factory can load it, and units in the field can be updated
Parts	Whatever the dev board's maker chose	Parts in stock at your volume, with alternates and published production lifetimes	One part with a 26-week lead time can hold up a whole run

Should you use a Wi-Fi or Bluetooth module that already holds FCC approval, or put the bare chip on your PCB?

For a first run of a few hundred to a few thousand units, use a module that already holds FCC approval, often called modular approval, rather than the bare chip.

• Radio approval. A module with modular approval covers most of the radio testing, as long as you meet the conditions of its approval: use an antenna the approval lists, put "Contains FCC ID" with the module's ID on your product, and check whether the approval assumes people stay at least 20 cm away. A wearable or handheld product, or a second radio, may need extra evaluation, and labs usually recommend a quick check of the radio inside your product. The finished product also needs its own emissions testing under FCC Part 15B, which checks that the electronics don't give off too much radio noise; see Who buys the parts for a first production run. Putting the bare chip on your board means getting the radio approved yourself. US labs list about $9,000 to $12,000 to test a Bluetooth or Wi-Fi radio for the FCC, with Canada and Europe on top; one documented approval in 2019 at a low-cost lab came to about $4,000 for the FCC and $12,200 for the US, Canada and Europe together.
• Engineering. A bare radio chip also needs antenna design and tuning with RF test equipment, usually a four-layer board, and weeks to months of RF work, with each RF revision adding weeks.
• Unit cost. The module's premium over the bare chip is small for some chip families: ESP32-family Wi-Fi and Bluetooth modules list for around $2 to $4 each in quantity, while modules built on other chips often cost more. And the bare chip still needs a crystal, usually external flash memory, antenna parts and often more board layers, all of which a module already includes. Savings of $1 to $4 a unit, before those parts, pay back the one-time cost of a bare-chip design only in the tens of thousands of units. The payback math is in Where does unit cost drop on a second production run.

Keep the antenna clear. One chip maker's layout guide puts the module's antenna at the edge of the board, cuts the board away around it, and keeps at least 15 mm between the antenna and anything else inside the case. Keep the USB lines, serial lines and their test points away from the antenna too, and test range in the finished case, with the battery in place. A metal case usually needs an external antenna that the module's approval covers, or a plastic window over the antenna, so decide that before the case is tooled.

Can you use a Raspberry Pi in a commercial product?

Yes, in three ways:

• A standard Pi board inside the case. No board design, but a fixed size and connectors, its own power needs, and an SD card to boot from, which can wear out or corrupt when power is cut, so products usually use a read-only file system or boot from other storage. It fits low volumes and products like kiosks, where size matters less.
• A Compute Module on your own carrier board. You design only the carrier board: power, connectors and the outline that fits your case. Versions with onboard flash boot from it instead of an SD card, the radio option holds modular approval, and the maker publishes production dates: Compute Module 4 until at least January 2034 and Compute Module 5 until at least January 2036. Prices have risen several times since late 2025 as memory costs climbed, so check current prices for the memory size you need. A Compute Module on a custom carrier board is the usual route for a commercial product built on a Raspberry Pi.
• A fully custom processor board. The most engineering by far, and rarely right for a first production run.

As with any module, the carrier board and the finished product still need their own emissions testing.

How does Arduino or ESP32 firmware change for production?

• From sketch to production build. On the ESP32, for example, the Arduino framework wraps the chip maker's own framework, ESP-IDF, and exposes only part of it. Features a product needs, such as secure boot, flash encryption, update rollback and power management, are easier to reach in ESP-IDF directly. You can run your Arduino code as a component inside an ESP-IDF project and move it over piece by piece.
• A build anyone can repeat. Keep the code in version control, fix the toolchain version, define the memory partitions, and add a watchdog that restarts a hung device, handling for low-voltage resets, and a test mode the factory can trigger.
• Per-unit data and keys. Many Wi-Fi and Bluetooth chips come with a factory-set network address, but you still need your own serial numbers, and often a device certificate or key for your cloud service. The factory writes these into each unit as it's flashed, so the board needs a way to do it. Keep your firmware signing key yourself: the factory needs only signed firmware. Where you can, have each unit generate its own private key and send out only a signing request, or use a security chip that arrives already loaded with keys, so private keys never sit in a file at the factory.
• Security settings. On many chips, secure boot and flash encryption are one-time settings: on the ESP32, once flash encryption is in release mode, a unit can't go back. On the original ESP32, the current secure boot scheme needs chip revision 3.0 or later, so check the module version before you buy. Decide these settings before the pilot build, because they change how the factory flashes units and how returned units can be reworked. Encrypting on first boot can take up to a minute per unit on the line, and power must not be cut while it runs.
• Updates. Build over-the-air updates in before the first run, with two firmware slots and automatic rollback, and test every update with the same bootloader the shipped units have.

Can you use an Arduino in a commercial product, or copy its board design?

This is general information, not legal advice:

• An unmodified Arduino board inside your product. You can sell a product with one inside without publishing your design, though, as above, a dev board rarely makes a good product.
• A board derived from Arduino's design files must be shared under the same Creative Commons Attribution-ShareAlike license. Designing your own board around the same chip from the chip maker's datasheet is a different matter from copying Arduino's files.
• Firmware built with the Arduino core and libraries. Many are under the LGPL, which doesn't make you publish your source code but does require letting users relink your firmware with updated versions of those libraries, for example by providing object files. Not every library uses the same license. A GPL library compiled into your firmware generally means releasing your whole firmware's source, and the version 3 licenses, GPLv3 and LGPLv3, also require letting buyers of a consumer product install modified firmware, which conflicts with locking units with secure boot. Keep a list of what's compiled in, and check it before you lock the first units.
• The name. "Arduino" is a trademark; don't use it in your product's name.

How much does a custom PCB cost to develop, and how long does it take?

Replacing a dev board with a first custom PCB typically costs about $8,000 to $40,000 in board design and $7,500 to $50,000 in firmware, over two or three revisions and about four to nine months. These are planning ranges from engineering firms and a module vendor, not quotes:

• Board design: about $8,000 to $40,000 for a first custom board around a module, depending on complexity.
• Firmware: about $7,500 to $50,000, depending on how much of the prototype code survives.
• Prototype boards: about $1,000 to $5,000 for each round of five to ten boards.
• Revisions: budget for two or three; some engineers say three to five for a whole new product.
• Time: about two to four months to the first working revision, then one to two months per revision, and four to nine months in all.

The per-unit saving is real, though smaller than retail prices suggest: an ESP32 dev board sells for about $8 while the module on it lists for $2 to $4, but a custom board still pays for its own circuit board, assembly and the parts around the module. A custom board also fits the case and lasts on a battery, which a dev board often can't.

Example: a plant sensor, 1,000 units

This is an illustration, not a customer project. The product and all the numbers are made up.

A team's prototype is an ESP32 dev board, a soil sensor and a temperature sensor on breakout boards, and a battery charger board, wired together inside a 3D-printed case. In testing, the battery lasts nine days, because the dev board draws about 8 mA between readings.

Their production board:

• Shape: a four-layer board, 45 × 30 mm, four layers for the small size rather than for the radio. It's drawn with the case so the sensors line up with openings, and the Wi-Fi module sits at the edge, with its antenna away from the battery.
• Power: a switching regulator, a charger and battery protection. Sleep current measures 15 µA, so battery life moves from days to months, depending on how often it wakes to send data. The battery pack already has a UN 38.3 test summary, which shipping requires, and the IEC 62133 certificate many retailers ask for.
• Factory test: programming pads and test points under the board. A pogo-pin fixture loads the firmware, writes a serial number and device key, and checks the sensors and Wi-Fi in about a minute.
• Revisions: revision A shows weak Wi-Fi with the battery in place, so revision B moves the battery and adds a missing pull-up on a boot pin. Revision C, with small fixes from B's testing, goes into the pilot build.

In this made-up example, the dev-board version cost about $31 a unit in boards and modules, and the custom board about $11 at 1,000 units. The custom path took a made-up $27,000 for board design, porting the firmware, three rounds of prototype boards and the test fixture, at the low end of the ranges above because the board is simple and most of the prototype code carried over. At $20 saved per unit, it pays back after about 1,350 units, so on the first 1,000 alone it is still about $7,000 behind. That leaves out the labor of wiring breakout boards into every case, which favors the custom board. The bigger reason is that it's the only version that fits the case and lasts on its battery. Emissions testing is needed either way.

Where we come in

If your prototype runs on a dev board, this is one of the situations Anamor takes on. Your firmware stays yours: we flash it on the line, and the programming fixture is itemized in the quote. We do not test or certify products ourselves; if you need FCC, UL or CE testing, we arrange it with an accredited lab, and the cost is itemized in your quote.

Anamor takes US hardware teams with a working prototype into their first production run: we redesign the product for production, line up partner factories and suppliers in the US and overseas, price it at your quantities, and run the build through to shipping.

Send what you have: photos or a video of the prototype, the dev board and parts you used, CAD if you have it, and how many you plan to make. Need an NDA? We'll send our mutual NDA, or review yours, before you send files. Within two business days, a real person on our team will reply with a free first look at your production run and a few times to talk.

Frequently asked questions

Can you sell a product with an Arduino or ESP32 dev board inside?

Yes. An unmodified Arduino board inside a product doesn't require you to publish your design, though you can't use the Arduino name for your product. But a dev board rarely makes a good product: it's too big for most cases, draws too much power asleep, and is slow to program and test on a production line.

Can you use a Raspberry Pi in a commercial product?

Yes. A standard Pi board inside the case suits low volumes and products like kiosks, but it usually boots from an SD card, which can wear out, and has a fixed size and connectors. Most products use a Compute Module on a custom carrier board instead, which can boot from onboard flash and has a published production lifetime. The product still needs emissions testing.

How much does it cost to turn a dev board prototype into a custom PCB?

Engineering firms' planning ranges are about $8,000 to $40,000 to design a first custom board around a module, $7,500 to $50,000 for firmware, and $1,000 to $5,000 for each round of five to ten prototype boards. Budget two or three revisions and four to nine months in all. Certification testing is extra.