Design Outdoor BLE Scale
Budget: $250 – $750 USD
I’m moving an outdoor Bluetooth Low Energy scale from concept to production and I’m looking for someone who can take full ownership of the design, optimise it for cost, and hand me a ready-for-manufacture package.
The target specification is straightforward: 200 kg maximum load, powered by a single 18650 Li-ion cell that recharges over USB-C. The scale will sit under a permanent, constantly changing load, so long-term accuracy and drift compensation matter. Energy efficiency is critical; the firmware must stay in deep sleep, wake on a configurable interval, sample weight, temperature and battery voltage, advertise the data, then drop straight back to sleep.
For the enclosure I’d like a mixed plastic-and-steel approach to balance weather resistance with price, though I’m open to going fully plastic or fully steel if you can prove a clear cost or performance benefit. A display is optional; please architect the electronics so a display header can be added without redesigning the core board.
Key deliverables
• Complete electronics package: schematic, PCB layout, Gerbers, pick-and-place files, tested BOM with unit cost targets.
• Embedded software: well-documented, low-power BLE firmware with a simple characteristic map and parameters to adjust the measurement cycle.
• Mechanical files: enclosure CAD, gasket details, and mounting points compatible with standard load cells.
• A brief test report demonstrating weight accuracy, temperature range performance, battery life projections, and baseline production cost.
I’m happy to iterate quickly, but the end goal is a design I can hand straight to my contract manufacturer, confident that every gram of material and every milliamp-hour has been justified. If this challenge fits your skill set, let’s talk timelines and get started.
The target specification is straightforward: 200 kg maximum load, powered by a single 18650 Li-ion cell that recharges over USB-C. The scale will sit under a permanent, constantly changing load, so long-term accuracy and drift compensation matter. Energy efficiency is critical; the firmware must stay in deep sleep, wake on a configurable interval, sample weight, temperature and battery voltage, advertise the data, then drop straight back to sleep.
For the enclosure I’d like a mixed plastic-and-steel approach to balance weather resistance with price, though I’m open to going fully plastic or fully steel if you can prove a clear cost or performance benefit. A display is optional; please architect the electronics so a display header can be added without redesigning the core board.
Key deliverables
• Complete electronics package: schematic, PCB layout, Gerbers, pick-and-place files, tested BOM with unit cost targets.
• Embedded software: well-documented, low-power BLE firmware with a simple characteristic map and parameters to adjust the measurement cycle.
• Mechanical files: enclosure CAD, gasket details, and mounting points compatible with standard load cells.
• A brief test report demonstrating weight accuracy, temperature range performance, battery life projections, and baseline production cost.
I’m happy to iterate quickly, but the end goal is a design I can hand straight to my contract manufacturer, confident that every gram of material and every milliamp-hour has been justified. If this challenge fits your skill set, let’s talk timelines and get started.