Helix Vape — Power Board

KiCad hardware design for the Helix temperature-control vape mod: a single-cell, USB-C powered board capable of delivering 1.0–10 V at up to 80 W into a heating coil, with closed-loop current/voltage sensing and an ESP32-C6 running the Helix-FW firmware.

The power stage is based on TI's PMP20410 reference design, re-implemented and integrated with the MCU, sensing, and user-interface circuitry on a single board.

Renders

Front	Back

Schematics

Power & analog front-end	MCU & digital

Click either schematic to open the full-size SVG.

How It Works

The board is a digitally-controlled buck-boost regulator. The MCU sets a target output via a DAC that injects into the regulator's feedback node, the ADC measures the actual coil current and voltage, and the firmware closes the loop with a PID controller. Because the regulator both bucks and boosts, it can hold a precise output regardless of where the battery sits in its discharge curve.

USB-C / Battery ──► LM5175 Buck-Boost ──► Q1–Q4 Power FETs ──► Coil
                         ▲                        │
                    MCP4726 DAC          RS1 / Rshunt sense
                         │                        │
                    ESP32-C6 ◄──────── ADS1015 ADC

Key Components

Ref	Part	Function
U1	LM5175PWP	4-switch synchronous buck-boost controller — the main 80 W power stage
U5	ESP32-C6-MINI-1U	RISC-V MCU + Wi-Fi/BLE module; runs the control loop, UI, and safety logic
U4	ADS1015IDGS	12-bit I²C ADC — differential coil-current sensing plus single-ended Vout/Vbat
U3	MCP4726	12-bit I²C DAC — injects into the LM5175 feedback node to set output (inverse scaling)
Q1–Q4	BSC010NE2LSI	25 V, ~1 mΩ power MOSFETs — the buck-boost switching bridge
U2	LMR62014XMF	Boost regulator for the auxiliary/gate-drive rail
U6	LP3986-30B3F	3.0 V LDO — clean rail for the MCU and analog parts
U8	USBLC6-2SC6	USB-C data-line ESD / TVS protection
J1	USB-C Receptacle (16P)	Charging and power input
RS1 / Rshunt1	2 mΩ / 10 mΩ shunts	High-side and coil current sensing
L1	680 nH, 23 A	Main power inductor (Chilisin)
BT1	1042 cell	Battery connection
SW1 / SW2	Push buttons	User input

Full bill of materials with LCSC part numbers is in PRODUCTION_FILES/BOM-helix_vape.csv.

Design Notes

• Inverse DAC feedback: higher DAC voltage produces lower output, so any logical fault or DAC reset biases the regulator toward a safe low-power idle (~1.0 V) rather than full power.
• Shared I²C bus @ 400 kHz ties together the ADC and DAC; the firmware arbitrates access to keep latency predictable under contention.
• Differential current sensing through the ADS1015 gives the firmware accurate, real-time coil current for PID power control and over-current safety.

Files

Path	Contents
helix_vape.kicad_pro / .kicad_sch / .kicad_pcb	KiCad project, schematics, and board layout
mcu.kicad_sch	MCU subsheet
PRODUCTION_FILES/	Gerbers, BOM, and CPL (pick-and-place) for JLCPCB
jlcpcb/	JLCPCB fabrication / assembly outputs
images/	3D renders and exported schematics

Manufacturing

Production files target JLCPCB assembly:

• PRODUCTION_FILES/GERBER-helix_vape.zip — fabrication Gerbers
• PRODUCTION_FILES/BOM-helix_vape.csv — bill of materials (LCSC part numbers)
• PRODUCTION_FILES/CPL-helix_vape.csv — component placement / pick-and-place

Firmware

The board is driven by Helix-FW, an async Rust (Embassy) firmware with a host-testable safety and control logic core.