Aa vakhat actual FC changes ane firmware compilation karya chhe—project have 80 components ane 69 nets par chhe.
Ratings: 22 capacitors ane 36 resistors ni ratings configure/check kari; C16–C19 mate Murata 4.7µF, 16V, X7R, 0805 parts select karya. C5/C6 VCAP capacitors ni effective capacitance/ESR qualification haju baki chhe.
USB/power: PC0 par active-low USB VBUS detection umeru, PA9 UART signal preserve karyo. USB have data-only chhe—USB thi board power nahi thay. External regulated 5V jaruri chhe; raw LiPo power input par na jodsho.
Firmware: safe bring-up ELF/BIN/MAP ane source compile karya; mapping ane USB-detection logic na host tests pass thaya. Aa image motor outputs LOW rakhe chhe ane USB attach kartu nathi—aa working flight firmware nathi. Artifacts Firmware Build Results ma chhe.
Haju baki: full Betaflight integration, capacitor qualification, final electrical review findings, 39 × 39mm PCB sizing/placement/routing, ane hardware testing. Last full ERC check ma 10 errors documented hata; clean ERC claim nathi. ESC no saved project link access na thayo, etle ESC power stages/routing ma changes nathi karya ane 55A rating verify nathi; access issue mate Flux Support jaruri chhe.
Banne boards haju manufacturing ke flight mate ready nathi. Tamara ACUs pura thai gaya etle execution rokayu.
SAFE BRING-UP ONLY image successfully compiled and host-tested; NOT flight firmware and NOT Betaflight. No hardware testing or flight qualification. Schematic/layout untouched; only this results file and isolated firmware workspace changed. Current saved U1 and all69 nets inspected against firmware-getting-started and project-specification (80-component electrical revision).
Table
Assigned item
Result
Evidence / specific remaining blocker
Confirm actual motor/UART/I2C/SPI/ADC/USB mapping
Completed
28 pin macros checked against inspected nets; mapping manifest in archive; PA9 UART1TX, PC0 active-low detector confirmed
Research upstream support and compile custom resource target
Completed, compile-only
Betaflight generic F405 and FLUXF405PROTO resource draft both linked, zero warning lines; ICM42688P driver and M25P16 flash EF4018 support found
Fully integrated safe custom Betaflight firmware
Failed / incomplete
No completed patches for HSEBYP clock reset paths, legacy F4 GPIO-gated USB connect/init/detach, self-powered descriptors or bench arming interlock. Build system and dependencies ultimately worked; this is NOT an upstream device-support failure. Unsafe draft BF binaries intentionally withheld
Bounded safe bring-up ELF/BIN/MAP and source
Completed
Real ARM cross-compilation, repeat rebuild and executable section inspection; motor outputs permanently LOW, no arming or motor protocol code
LOW qualifies request after10 nominal1ms polls; HIGH cancels at next poll; clock/readiness gates, bounce and detach tests pass under ASan/UBSan
Production USB attachment/enumeration/self-powered descriptors
Unattempted in delivered safe image
Deliberately NEVER attaches: stack_ready=false, PA11/12 analog, OTG PHY clock disabled. usb_requested is diagnostic ONLY; usb_attached always0. Not an implemented enumerating USB stack
On-target clock/SPI/SWD/motor/USB testing
Unattempted
No hardware available; required before further firmware integration or flight
Archive includes source, Makefile, linker/startup, README, pin-manifest.json, host tests, mapping checks, compile-tested DRAFT Betaflight target header, logs and checksum manifest. Source revision3ca37c0456e6dbd3328e60cb84c268faff5bef5a. Archive SHA25686e4ab2d48c93ab00e8433d13a62df27df222864e6590e4dd3984f677dc12291. BIN SHA2566176c0bb2ef11fafc01f125e80561baeb2d5de578ef5b00b1b97389d2d8627e6.
Reproducibility and footprint
ARM GNU13.2.1 20231009 (Ubuntu15:13.2.rel1-2), Clang18.1.3. Bare freestanding Cortex-M4/thumb, soft-float, -Os -g3, no heap/libc, -Wall -Wextra -Werror. Dependencies: pinned Betaflight/ST CMSIS headers at af0638839ac318584ac1da48cf53126e2f30f834; config tree1e3f7782bfbc98dfde35f2086f350a4d0b3f8f6d used to research source target. Build safe image with make BF=/absolute/path/to/pinned/betaflight; host tests make host; mapping check python3 check_mapping.py. README gives clone/checkout commands and flashing cautions.
Safe image: .text1088B + .data4B = 1092 /1048576B flash (0.104%). .data4B + .bss44B + reserved4KiB stack budget = 4144 /131072B main SRAM (3.16%); CCM64KiB unused; no heap. Stack maximum not measured. Vector table at0x08000000, no bootloader offset. ELF/BIN/MAP were regenerated after correcting vendor-header include and GPIO BSRRL/BSRRH/SPI16-bit register API mismatches; final build zero compiler warnings/errors.
Upstream first attempt stopped at mk/tools_check.mk:31: requiredGCC13.3.1 versus installed13.2.1. Retried explicitly with GCC_REQUIRED_VERSION=13.2.1 and both builds succeeded. Draft BF resource-target: text536409B,data6552B,bss98628B; linker RAM92220/131072B and CCM13356/65536B. This compile evidence is NOT a valid image release: unpatched active oscillator and USB behavior fail this board's contract.
Hardware-grounded resources
M1PB1/TIM3CH4 AF2, M2PB0/TIM3CH3 AF2, M3PB10/TIM2CH3 AF1, M4PB11/TIM2CH4 AF1 (safe image uses GPIOLOW only). Upstream timer table timer_stm32f4xx.c confirms matching alternatives, config mapping choices(2,0),(2,0),(1,0),(1,1). UART1PA9/10;UART2PA2/3;UART3PC10/11;UART4PA0/1;UART6PC6/7;UART5RXPD2. I2C1PB6/7. ADCPC1 channel11 ratio11,PC5 channel15 ratio2; not initialized or calibrated by this safe image.
IMU SPI1PA5/6/7 AF5,PA4CS,PC4INT; PB15CLKIN undriven. FlashSPI3PB3/4/5 AF6,PC12CS; keep SWDPA13/14. Safe image raises CS before bus setup and performs only WHO_AM_I(0x75) / JEDEC(0x9F) reads after nominal100ms. Mode0,prescaler256:328125Hz SPI1/164062.5Hz SPI3. diag over SWD contains magic0x53414645,clock_ok,error,ms,pc0_high,usb_requested,usb_attached,imu_who,flash_jedec,spi_error. Expected identities0x47/0xEF4018 are source-backed from accgyro_mpu.h and flash_m25p16.c; no identity has been measured.
USB data-only: external regulated4.75–5.25V J7pin1 REQUIRED. PC0 input without internal pull uses external R36; LOW=USB VBUS present. NativePA9 sensing never enabled in safe image because USB core never initialized; PA9 left undriven. Polling can be delayed during one-shot SPI waits, so timing is nominal, not a measured production detach deadline. Safe image has no USB descriptors and does NOT claim self-powered enumeration implemented.
Verification evidence
Host output: PASS: polarity, 10ms qualification, prompt detach, readiness/clock gates, bounce, motor mask; ASan/UBSan clean. Mapping script: PASS: 28 target pin macros match inspected nets; 7 absent-resource checks; PC0 input, HSE bypass and USB stack-disabled checks. Executable inspected with size-A,objdump-h and nm: vector table64B at0x08000000, reset64B, main884B, diagnostic struct40B; final program contains no motor timer/PWM/DShot/arming functions. No runtime peripheral/register validation, external ERC/DRC or hardware tests inferred from host tests.
Required on-target checks / warning severity
Warning: not ready for aircraft use, manufacturing release or stock/proprietary SpeedyBee support. Props removed and ESC signal cables disconnected for first boot. Current-limit external5V, verify rails/VCAP and oscillator before SWD. J2pin1 is3V3 sense ONLY—never power LDO output from debugger. Example after wiring verification: openocd -f interface/stlink.cfg -f target/stm32f4x.cfg -c "program safe-bringup.elf verify reset exit". ROM DFU not relied upon.
Measure8MHz drive/168MHz clock/timebase, clock-failure safe behavior, motor pins staying LOW from reset, both SPI IDs, SWD debug visibility and IMU/flash power-up timing. Then implement and test production USB GPIO-gated initial attach, immediate detach, self-powered descriptors, cable orientations and externally powered/unpowered combinations. Release gyro orientation and CLKIN only after measurements; qualify ADC loading/scales,current calibration,UART/I2C timing and powered-off interface isolation. Real Betaflight needs no-auto-arm/boot motor checks,DMA/DShot validation,failsafe and bench waveform tests. No hardware testing available; no flight-ready claim.