KiCad Export

Thought for 55 sec

Sorry—my previous answer was incorrect. Flux does not currently offer a native KiCad .kicad_pcb export.

In Flux’s Export menu, the PCB fabrication option is Manufacturing Files (Gerbers, etc.). These Gerber/drill files can be viewed in KiCad’s Gerber Viewer, but they are not an editable KiCad PCB project.

amirghasemi21

the PS/SYNC (U4 pin 7) on the 3V3 net? or should it be on GND?

Thought for 7 sec

flux

For this battery-powered sensor, U4 pin 7 (PS/SYNC) should normally connect to GND.

GND/LOW: enables power-save mode, improving light-load and ESP32 sleep efficiency.
3V3/HIGH: forces PWM operation, giving lower ripple but consuming more standby current.
It should not normally be powered from U4’s own 3V3 output, because that output is unavailable during startup.

Use 3V3 only if you deliberately need forced-PWM operation; otherwise connect pin 7 directly to GND.

amirghasemi21

check the current schematic, how is it now?

Thought for 4 sec

flux

I’ll inspect U4 pin 7’s current net and verify the surrounding TPS63001 connections.

Worked for 26 sec

flux

Currently, U4 pin 7 (PS/SYNC) is connected to the 3V3 net, along with VOUT and FB. That selects forced-PWM operation.

For this battery sensor, I recommend moving PS/SYNC to GND to enable power-save mode and reduce sleep/standby consumption. U4’s GND, PGND, and exposed pad are already connected to GND.

Fix and verify regulator

Move PS/SYNC to GND

Verify regulator wiring

Run schematic review

Explain power-save mode

Files

Schematic

Layout

3D View

Technical Construction File — ESP32-C6 CO2 Sensor

Status

Draft — schematic stage.

Product Description

Battery-powered environmental sensor using ESP32-C6-WROOM-1-N8 for Thread wireless communication and SCD41 for CO2/temperature/humidity measurement. USB-C provides charging and data/programming.

Applicable Regulations

FCC Part 15 intentional radiator: required because ESP32-C6 includes 2.4 GHz radio.
CE RED: required for EU wireless products.
ISED/UKCA: likely required depending sales region.
Battery/charger safety review: required because the design charges a LiPo cell.

Wireless Technology Summary

Table

Module	MPN	Technology	Band	Notes
U1	ESP32-C6-WROOM-1-N8	Thread / 802.15.4, Wi-Fi 6, BLE	2.4 GHz	Use module certification and obey antenna keepout/integration rules.

Current Compliance Evidence

Schematic includes ESP32-C6 certified module rather than bare RF IC.
USB D+/D- ESD protection added with D1.
USB-C sink CC resistors added on CC1/CC2.
LiPo charging handled by BQ24074 power-path charger.

Required Documentation Checklist

Product description drafted.
Wireless module identified.
Preliminary safety/FMEA notes included below.
Final schematic export.
Final PCB layout/Gerbers after layout.
ESP32-C6 module grant/certification documents.
Antenna keepout evidence from final PCB layout.
EMC/RF test reports from accredited lab.
Final user manual and labeling.

Preliminary Safety / FMEA Notes

Table

Subsystem	Failure Mode	Effect	Mitigation
LiPo charger	Overcurrent or thermal stress	Heat, reduced battery life	BQ24074 charger, PTC fuse, verify charge settings and thermal rise during bring-up
USB input	ESD event	MCU/USB failure	D1 USB ESD protection, shield/GND connection
Buck-boost regulator	3V3 out of range	MCU/sensor malfunction	Verify 3V3 under RF bursts; keep switching layout compact
Battery connector	Reverse polarity	Damage risk	Use keyed JST PH connector; verify polarity in bring-up plan
RF module layout	Antenna blocked by copper/enclosure	Poor Thread range, certification risk	Keep antenna keepout clear in layout

Open Items Before Manufacturing

Confirm ESP32-C6-WROOM-1 module certification identifiers and integration constraints.
Confirm final enclosure/battery labeling requirements.
Complete layout with antenna keepout and USB differential-pair routing constraints.

Status
Product Description
Applicable Regulations
Wireless Technology Summary
Current Compliance Evidence
Required Documentation Checklist
Preliminary Safety / FMEA Notes
Open Items Before Manufacturing