Open-hardware electronics for a 5-inch 6S FPV quad: a flight controller, a 4-in-1 ESC and a GPS, designed in KiCad 10 and DRC clean.
 Kestrel H7 FPV flight controller |
 Kestrel 4in1 6S 4-in-1 ESC |
 Kestrel GPS GNSS and compass module |
Three boards, plus the most common off-the-shelf modules every FPV build already buys (a digital HD VTX, an ExpressLRS receiver, 22xx motors, 5-inch props and a 6S pack):
- Kestrel H7 (FPV flight controller, 40 x 40 mm, 6 layers): An STM32H743 flight controller for 5-inch 6S quads: two IMUs, a barometer, a 16 MB blackbox and its own 5 V and switchable 10 V BECs, on a 30.5 mm stack.
- Kestrel 4in1 (6S 4-in-1 ESC, 48 x 52 mm, 6 layers): Four STM32G071s running stock AM32, twelve half-bridge drivers and twenty-four 60 V FETs stacked through a 48 x 52 mm board, with battery current sensing for the flight controller.
- Kestrel GPS (GNSS and compass module, 28 x 28 mm, 4 layers): A u-blox MAX-M10S under a 25 mm ceramic patch, with an LIS3MDL compass, on a 28 x 28 mm board that plugs 1:1 into the Kestrel H7.
SPEC.md |
the system, each board's design, why each part, and what is not done |
BUILD.md |
the off-the-shelf parts, the harnesses, the FC's pad map, ordering and first power-up |
BOM.md |
the whole drone's parts; costs/ prices each board's BOM line by line |
RESULTS.md |
measured: ERC, routing, DRC, DFM, fab gate and parts cost per board |
| Firmware | a Betaflight target in kestrel-fc; stock AM32 on the ESC, mapped in kestrel-esc |
Not fabricated, assembled, powered or flown yet. SPEC.md says what each claim rests on, and every
number in RESULTS.md is read from the boards' own reports.
Designed with the HeyPCB method on KiCad 10.0.6, headless, by the heypcb-kicad pipeline: a written brief composed from reusable circuit blocks, every pin from KiCad's own symbol library, every part bound to an LCSC number from a dated catalogue read, then ERC, a netlist round trip, locked placement, Freerouting 2.4.1, pours and stitching, silkscreen, DRC with schematic parity, DFM and a fab gate, each stage gated by a measurement. Each board's design/make_brief.py regenerates its brief from code.
Hardware and documentation: CERN-OHL-S v2. The Betaflight target in kestrel-fc is GPL-3.0, the licence of the betaflight/config repository it builds in.