Case study · IoT hardware · Product development
From PCB to product: portable industrial data logger
Most hardware startups hit the same wall: the electronics work, the firmware runs — but translating a validated PCB into a manufacturable, market-ready product is an entirely different problem. This project documents exactly how that gap gets closed.
Electronics are the easy part
Environmental monitoring is a solved problem at the circuit level. BME280 sensors, ESP32 microcontrollers, LiPo charging circuits — the components exist, they're cheap, they work. The hard problem is everything that happens next: how do you package those components into something a human can hold, a factory can assemble, and a supply chain can reproduce at scale?
The PDL-1 project was built to answer that question end-to-end. The brief was deliberately constrained: a battery-powered IoT logger measuring temperature, humidity, and pressure — using off-the-shelf modules, a compact two-part enclosure, and a functional prototype that could be handed to a manufacturer as a starting point for tooling.
“The real challenge wasn't fitting three boards into one shell. It was giving each board its own standoff height, its own clearance, and its own access point — without turning the enclosure into a maze.”
Defining what goes inside before designing the outside
Before any geometry was sketched, the internal architecture had to be fixed. Component selection directly constrains enclosure geometry — a decision made in the BOM shows up as a wall thickness, a keep-out zone, or a snap-fit tolerance three weeks later.
The ESP32-S3 Feather was chosen because its integrated charging circuitry removes the need for a separate power management board — eliminating one PCB, reducing internal height by roughly 4 mm, and simplifying cable routing. These are the kinds of decisions that only matter once you're designing an enclosure around them.
Hardware specifications — selected components
Brass inserts and a pressure-equalising membrane
The cover does more than close the enclosure — it carries the hardware that holds the whole assembly together and manages environmental sealing for the sensor. Four threaded brass inserts are heat-set into the cover to receive the assembly screws, and the enclosure houses a pressure membrane that lets the internal sensor (BME280) read true ambient pressure without exposing the electronics to moisture or dust.
That single conflict between sensor exposure and component protection drove most of the mechanical decisions that followed.
Hardware BOM
| Component | Part number | Function |
|---|---|---|
| Threaded inserts | 071M3 | Heat-set into the cover; receive the body-to-cover screws |
| Pressure membrane | PE30509 | Equalises pressure to the internal sensor while sealing against dust and moisture |
| Body-to-cover screws | 1154257 — M3 × 4 | Secure the cover to the body via the 071M3 inserts |
| PCB mounting screws | 200075 — M2.2 × 12 | Secure all PCBs to their standoffs inside the body |
Designing the plastics around the stack
With the cover's sealing strategy fixed, the body was developed around the actual standoff heights and cable paths required by the board layout. Every post in the body has a defined job: some carry screw bosses for the M2.2 PCB screws, some are pure structural standoffs, and others double as alignment guides during assembly.
The rounded cutout on the side wall lines up with the USB-C connector on the main board, and the body's outer profile carries the four corner bosses that receive the inserts from the cover.
The choices that shaped the product
Every mechanical design is a negotiation between competing constraints. Here are the decisions that most directly shaped this enclosure:
Three separate boards vs. one consolidated PCB
ProEach board can be developed, sourced, and revised independently — lower risk during early validation.
ConRequires three distinct standoff heights and more internal volume than a single board would need.
Brass inserts vs. self-tapping into plastic
ProWithstands repeated assembly and disassembly cycles without stripping — consistent clamp force every time.
ConAdds a secondary heat-insertion step and higher per-unit cost compared to self-tapping screws.
Dedicated membrane window vs. open vent
ProThe sensor reads true ambient pressure while moisture and dust stay off the PCB surface.
ConAdds one more component and a sealing surface that must be held to a tighter dimensional tolerance.
M2.2 PCB screws vs. snap-fit board retention
ProEach board is independently serviceable without disturbing the position of the others.
ConAdds extra fasteners and assembly steps compared to a clip-in retention design.
A serviceable, sealed, multi-board enclosure
The PDL-1 project delivered a complete mechanical package built around a real multi-board stack: a body with individually sized standoffs and cable routing, and a cover combining structural screw bosses with a dedicated, sealed pressure-sensing window.
Final deliverables included the full body and cover CAD models, a defined hardware BOM covering inserts, membrane, and fastener part numbers, and a structure ready to be carried into prototype manufacturing.
From device to dashboard
To support evaluation of the PDL-1 concept, a prototype monitoring interface was developed to visualize environmental data collected by the device. The platform demonstrates how temperature, humidity, atmospheric pressure, battery status, and alarm conditions can be presented through a centralized dashboard.
Features include historical trend visualization, device status monitoring, report generation, and a location-based map view for identifying active and offline devices. The interface was developed as a proof of concept to validate the overall user experience and system architecture of a connected environmental monitoring solution.
Try it below: select a device on the map, change the alarm limits, compare two rooms on the chart, acknowledge an alarm or export the data. The readings are simulated in your browser — no real device data is shown.
Interactive demo of the PDL-1 monitoring dashboard. Simulated readings: 4 devices, one reading every 10 minutes for the last 7 days.
Services behind this project
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