Smart Espresso Scale
Worked for 2 mins 29 sec
Created 5 project docs
Firmware Starter — ESP32-S3 Smart Espresso Scale
MCU: ESP32-S3-WROOM-1-N8R8 (U4) Framework: Arduino on PlatformIO
View docBoard Bring-Up Plan — Smart Espresso Scale
Equipment: current-limited USB supply, multimeter, oscilloscope, USB-C cable, known calibration weights, Li-ion cell simulator or protected ...
View docTechnical Construction File — Smart Espresso Scale
Draft FCC Part 15 intentional radiator / modular transmitter integration review
View docSafety Analysis — Smart Espresso Scale
Draft Low-voltage, USB-C powered, single-cell Li-ion battery product. No mains voltage is present on the PCB.
View docPreliminary FMEA — Smart Espresso Scale
Design-stage FMEA for a USB-C rechargeable BLE espresso scale with Li-ion battery, load-cell ADC, display, and microSD logging. | Subsystem ...
View docDesigned the smart espresso scale schematic and renamed the project Smart Espresso Scale. The schematic now has 55 components / 44 nets, including USB-C power/ESD, BQ24295 Li-ion charger/power-path, 3.3 V regulation, ESP32-S3 BLE MCU, NAU7802 load-cell AFE, microSD logging, I2C OLED display, buttons, and status LEDs; verification found no open ERC/component/footprint errors in the checked categories.
Project files created:
- Project Specification
- Block Diagram
- Reference Recreation Ledger
- Power Budget
- Firmware Starter
- Board Bring-Up Plan
- Technical Construction File
- Safety Analysis
- Preliminary FMEA
Open items:
- Select the final Li-ion cell capacity and set BQ24295 charge current accordingly; firmware currently notes a conservative ≤512 mA target.
- Validate TLV1117 dropout/thermal margin during BLE + display + SD write bursts.
- Verify the exact OLED/display module pinout and 3.3 V compatibility before production.
- PCB layout still needs antenna keepout, charger/regulator thermal layout, and load-cell analog routing care.
Suggested next steps:
- Proceed to PCB board size/constraints and component placement.
- Choose the final battery capacity and enclosure/display mechanical constraints.
- Run PCB layout with ESP32 antenna keepout and load-cell analog separation.
- After placement, route and run full DRC/PI/SI checks.
Layout and fix risks
Proceed to layout
Fix open risks
Set design constraints
Run schematic review
Refine this doc
Ask about this doc
Project Specification — Smart Espresso Scale
Goal
Design a phone-connected smart espresso scale powered from USB-C with single-cell Li-ion battery operation, local data logging, and an integrated display.
Architecture Decisions
- Connectivity: BLE to phone; choose an ESP32-S3 module for mature Bluetooth support and firmware ecosystem.
- Measurement: 24-bit load-cell ADC front end for one 4-wire espresso-scale load cell, with provision for a second differential channel if the selected reference block includes it.
- Power: USB-C 5 V input with sink CC pull-downs and ESD protection; single-cell Li-ion charger/power-path manager; 3.3 V logic rail from the system/battery rail.
- Storage: microSD card for local shot logs and calibration/history data.
- Display: compact segment/OLED-style screen interface; use a 3.3 V I2C display where practical to avoid high-current display power rails.
- Human I/O: tare/start controls and status/charge indicators where supported by selected references.
Assumptions
- Board is low-voltage only; no mains.
- Display is a small low-power screen suitable for an espresso scale enclosure.
- Load cell is external or mechanically mounted off-board and connects via a small header.
- USB-C is for 5 V power and optional USB 2.0 device/programming, not USB-PD.
Power Budget Snapshot
Target 3.3 V loads: ESP32-S3 BLE bursts, NAU7802 load-cell ADC, microSD transients, I2C display, status LEDs. Size the charger/system rail and 3.3 V regulator for at least 500 mA peak margin due to ESP32 and microSD bursts; average scale operation is expected to be much lower.
Goal
Architecture Decisions
Assumptions
Power Budget Snapshot
