6/6 Run schematic/design checks and fix actionable issues
Rename project, create specification, and record initial requirements/power budget
Select library parts for MCU, T/RH sensor, USB-C input, regulator, and protection
Add main components and supporting passives to the schematic
Wire USB-C power/protection, 3.3 V rail, MCU boot/debug, USB data, I2C sensor, and indicators
Create firmware/regulatory/bring-up project files
Run schematic/design checks and fix actionable issues
Thought for 46 sec
Reading project docs.
Getting a BOM overview.
Completed 11 design checks — found 114 issues.
Thought for 42 sec — Verifying eFuse features
Read U2, TPS259530DSGT datasheets.
Thought for a moment
Searching for eFuse solutions
I need to address the issue with TPS2596 that requires fixing since the user needs the reverse. It looks like I have to replace or add an ideal diode. To do that, I should search for a part with back-to
Thought for 6 sec
19 days ago
Thought for a moment
Searching for eFuse solutions
I need to address the issue with TPS2596 that requires fixing since the user needs the reverse. It looks like I have to replace or add an ideal diode. To do that, I should search for a part with back-to-back eFuse in the library. It’s essential to find the right replacement to meet the user's requirements. Let’s get started on that!
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A consumer USB-C powered temperature and relative humidity sensor node with Wi-Fi and Bluetooth Low Energy connectivity. The board uses a protected USB-C 5 V sink input, local 3.3 V regulation, a low-power Wi-Fi/BLE MCU module, and a digital I2C T/RH sensor.
Intended Use
Indoor consumer environmental monitoring node.
Powered from USB-C 5 V chargers, hubs, or ports.
Designed for prototype-to-production learning; not medical, industrial safety, or outdoor/weatherproof use unless later specified.
What the Device Should Do
Measure ambient temperature and relative humidity.
Connect over 2.4 GHz 802.11 b/g/n Wi-Fi.
Support BLE 5.x provisioning or local telemetry.
Power from USB-C default 5 V sources.
Survive common consumer input faults with reverse-current, overvoltage, undervoltage, and overcurrent protection.
Main Features
USB-C receptacle configured as sink-only with independent CC1/CC2 5.1 kΩ Rd resistors.
Protected 5 V input sized for 0.5–3 A capable sources, while the node itself is expected to draw well below 500 mA average.
3.3 V logic rail for MCU and sensor.
Native USB data/programming path where supported by the selected MCU.
Boot/reset controls, debug/programming access, and status LED.
System Architecture
Diagram
Hardware Subsystems
Power input: USB-C receptacle, CC pull-downs, VBUS ESD/TVS, protected power switch/eFuse or load switch with OVP/UVLO/OCP/reverse-current blocking.
Regulation: 5 V to 3.3 V rail sized for Wi-Fi transmit current peaks.
Compute/radio: certified ESP32-family module preferred to avoid custom RF matching and simplify regulatory work.
Sensor: digital I2C temperature/humidity sensor with local decoupling and one shared I2C pull-up pair.
User/debug: reset and boot controls, status LED, USB programming, optional exposed test/debug header.
Interfaces and Connections
External: USB-C 5 V power and USB 2.0 D+/D- for programming/debug.
Internal: 3.3 V rail, GND, I2C SDA/SCL, boot/reset, status LED GPIO.
RF: integrated 2.4 GHz antenna module; PCB layout must provide the module antenna keepout.
Power and Runtime Expectations
Source: USB-C 5 V default power only; no battery in this revision.
Source capability planning: tolerate 0.5 A, 1.5 A, and 3 A capable USB-C sources. Do not assume the device may draw 3 A unless CC current advertisement is measured/implemented.
Low-power behavior: firmware should sleep between samples and radio transmissions, but USB-powered operation makes absolute sleep current less critical than thermal and regulatory behavior.
Power Tree and Power Budget
Table
Rail
Load
Sleep
Typical active
Peak
3.3 V
Wi-Fi/BLE MCU module
~10–100 µA deep sleep
~80–240 mA radio active
~500 mA short Wi-Fi TX burst
3.3 V
T/RH sensor
<1 µA standby
~0.5–1 mA measuring
~1 mA
3.3 V
Status LED
0 mA off
~2 mA on
~5 mA configured max
3.3 V
Pull-ups/leakage
~1–2 mA worst when lines low
negligible average
~1.4 mA for two 4.7 kΩ pull-ups low
Estimated 3.3 V rail sizing target: 250 mA typical active, 510 mA transient peak. For an LDO from 5 V, input current is approximately output current; thermal at 250 mA is about (5.25 V - 3.3 V) × 0.25 A = 0.49 W, so a small SOT-23 LDO may be marginal during sustained Wi-Fi. Preferred choices are a high-current low-Iq regulator in a thermally capable package or a quiet buck regulator if sustained radio current/thermal limits demand it.