KiCad Export


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.
the PS/SYNC (U4 pin 7) on the 3V3 net? or should it be on GND?
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.
check the current schematic, how is it now?
I’ll inspect U4 pin 7’s current net and verify the surrounding TPS63001 connections.
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

D1
U1
U2
J1
U3
C1
Capacitance
1uF
L3
Inductance
2.2uH
C10
Capacitance
1uF
C3
Capacitance
4.7uF
C2
Capacitance
4.7uF
C7
Capacitance
0.1uF
C11
Capacitance
4.7uF
C5
Capacitance
10uF
C6
Capacitance
10uF
C9
Capacitance
0.1uF
C8
Capacitance
22uF
C4
Capacitance
10uF
Buck-Boost Regulator
R10
Resistance
10kΩ
R2
Resistance
5.1kΩ
R13
Resistance
1.0MΩ
R9
Resistance
10kΩ
R11
Resistance
10kΩ
R6
Resistance
46.4kΩ
R7
Resistance
100Ω
D2
R5
Resistance
4.12kΩ
J2
R15
Resistance
10kΩ
R14
Resistance
1.0kΩ
R3
Resistance
1.13kΩ
SW1
R4
Resistance
1.18kΩ
R8
Resistance
10kΩ
R1
Resistance
5.1kΩ
R12
Resistance
1.0MΩ
SW2
F1
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


ModuleMPNTechnologyBandNotes
U1ESP32-C6-WROOM-1-N8Thread / 802.15.4, Wi-Fi 6, BLE2.4 GHzUse 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


SubsystemFailure ModeEffectMitigation
LiPo chargerOvercurrent or thermal stressHeat, reduced battery lifeBQ24074 charger, PTC fuse, verify charge settings and thermal rise during bring-up
USB inputESD eventMCU/USB failureD1 USB ESD protection, shield/GND connection
Buck-boost regulator3V3 out of rangeMCU/sensor malfunctionVerify 3V3 under RF bursts; keep switching layout compact
Battery connectorReverse polarityDamage riskUse keyed JST PH connector; verify polarity in bring-up plan
RF module layoutAntenna blocked by copper/enclosurePoor Thread range, certification riskKeep 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