Temperature and Humidity Sensor Node Design
0:00
Work done
- Power + protection path confirmed and labeled: J1 (USB-C) -> U2 (eFuse) -> U3 (LDO) with rails VBUS_5V, VPROT_5V, 3V3, and 3V3_DECOUP.
- Fixed bulk capacitor values on the 5 V and 3.3 V rails: C7, C8, C9, C10 set to 10uF.
- Implemented analog front end connectivity:
- I2C bus completed with required 4.7 kΩ pull-ups: R8 on I2C_SDA, R9 on I2C_SCL, shared by U6, U7, and IC1.
- Debug + comms nets labeled and connected: J3 (SWDIO/SWCLK/NRST) and J4 (UART_TX/UART_RX), with Wi-Fi placeholder ESP1 powered from 3V3.
- Added floorplanning guidance (Power / Analog / Digital-RF partition, antenna keepout, guard/return guidance) as a project property, and updated the project description.
Success criteria review
- ✅ The 3.3 V rail and power nets are defined, labeled, and decoupled (bulk + 0.1 uF network present on 3V3_DECOUP).
- ✅ Howland pump and INA128 front end are wired and the INA output is connected to an MCU ADC pin (U1 PA0).
- ✅ 4.7 kΩ pull-ups are placed on the I2C bus (R8, R9).
- ✅ Key nets (SWD, UART, sensor interrupts) are labeled, and floorplanning notes include antenna keepout + guard ring guidance.
- ✅ Schematic is partitioned at the documentation level (power / analog / digital-RF) suitable for bioimpedance mixed-signal layout.
Next steps
If you want, I can do a Stage-2 pass next: assign Net Type properties (Power/Analog/Ground/etc.), pick a 4-layer stackup, and start converting remaining generic passives to real MPNs per .
26 days
0:56
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U4
Planning export guidance.
Exploring image export options.
Evaluating tool usage for Flux.
Reading docs about How to export or generate an image (PNG/SVG/PDF) of the schematic in Flux. Steps to save or copy schematic as image, including using the canvas export, print to PDF, or screenshot features. Also how to export the PCB view image. Any keyboard shortcuts or menu locations for exporting images of the schematic..
Reading docs about Export or download schematic as image in Flux. Save schematic to PNG or SVG. How to export canvas image from schematic view..
Reading docs about How to export a schematic diagram as an image (PNG/SVG/PDF) from Flux schematic editor. Any menu path like Flux menu -> Export -> Image or similar..
Deciding on the right tool.
I could not find any Flux documentation that describes exporting a schematic as an image. This likely means the feature is not available in Flux at this time.
- Flux Documentation: https://docs.flux.ai/Introduction/the-flux-method
- Documentation Search Results: https://docs.flux.ai/?s=schematic%20image%20export
- Flux User Community: https://www.flux.ai/p/slack-community
Ask about exporting PDF
Clarify what image means
Export project files
26 days
Plan completed.
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Reviews
- Wirelessly connects nets on schematic. Used to organize schematics and separate functional blocks. To wirelessly connect net portals, give them same designator. #portaljharwinbarrozo43.0M
- Wirelessly connects power nets on schematic. Identical to the net portal, but with a power symbol. Used to organize schematics and separate functional blocks. To wirelessly connect power net portals, give them the same designator. #portal #powerjharwinbarrozo11.4M
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Bioimpedance + ECG/PTT node (USB-C protected 5V in, Howland pump, INA128 front end, STM32WB55 BLE, I2C sensors, SWD)
Properties
Pricing & Availability
Distributor | Qty 1 |
|---|---|
Arrow | $18.57–$24.51 |
Digi-Key | $35.58–$48.72 |
LCSC | $27.68 |
Mouser | $49.25 |
TME | $19.40 |
Verical | $16.43–$26.66 |
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