Environmental Node Requirements
User-requested product
Consumer-use, low-power temperature and humidity sensor node powered by USB-C at 5 V, with a digital temperature/relative-humidity sensor and an ultra-low-power MCU supporting both 2.4 GHz IEEE 802.11 b/g/n Wi-Fi and Bluetooth Low Energy 5.x.
Power requirements
- USB-C receptacle, 5 V default operation.
- Include reverse-current/polarity protection as applicable to the chosen power path, overvoltage protection (OVP), undervoltage lockout (UVLO), and overcurrent protection (OCP).
- Plan for sources rated 0.5–3 A. Source rating is available capacity, not permission for the sink to draw that current: determine allowed input current from the applicable USB connection and Type-C advertisement before drawing above the permitted level.
- No USB Power Delivery voltage negotiation requested.
- Size the regulator and input path for radio burst loads while minimizing idle consumption; numerical budgets remain to be established.
Design direction to evaluate, not yet verified
- Integrated Wi-Fi/BLE MCU module with antenna to reduce RF implementation risk; verify exact Wi-Fi and BLE versions, low-power modes, and consumer-product certification implications before selection.
- Digital I2C temperature/humidity sensor, positioned away from regulator and MCU heat and near enclosure ventilation.
- Protected 5 V input feeding an efficient 3.3 V regulator, with suitable transient and ESD protection.
- USB-C sink CC termination and a current-awareness strategy appropriate to the actual load and supported sources.
- Consumer enclosure with airflow, connector access, and RF antenna clearance; mechanical requirements remain undefined.
Open requirements
- Temperature/RH accuracy, measurement range, reporting interval, and acceptable sensor self-heating/error.
- Wi-Fi/BLE operating roles, whether simultaneous operation is required, provisioning flow, and data endpoint/protocol.
- Size, mounting, indoor/outdoor environment, enclosure protection, indicators, and user controls.
- Meaning of low power: target average consumption, always-connected versus duty-cycled radio operation.
- Whether USB data is needed or USB-C is power only; firmware programming/update interface.
State at session end
Only this requirements handoff was created. The project started with zero components and zero nets; no schematic, component selection, PCB layout, enclosure, firmware, live research, or electrical verification was performed. No part numbers or protection thresholds have been validated.
Resume work
Resolve only requirements that materially affect architecture, select and verify an appropriate radio MCU/module and digital sensor, establish current and thermal budgets, then design the protected USB-C input and regulator. Capture and verify the schematic before proceeding to PCB placement/routing and enclosure design. Include firmware/provisioning and consumer compliance planning in the product scope.
Execution could not proceed because the account's ACUs ran out.