Drone Autonomy Spec

Worked for 7 sec

flux

Escalated internally to the Flux engineering team with:

Compute Vision Board link
HTTP 524 preflight failures
Partial auto-route corruption
Airwire increase from 247 to 442
Ground-fill/stitching-via corruption when applying routing rules
Clean recovery commit c52f37c6
Current safe board state

For a human support case and status follow-up, use Contact Support and reference the KRYSTAL Compute Vision Board routing/rules corruption issue.

olivier1970

write a reportwith all info for a new engineer to take over the PCB and fix it.

Thought for 9 sec

flux

I’ll create a structured takeover report covering both boards, architecture, completed work, current live state, known blockers, recovery history, verification gates, and the exact order a new engineer should follow.

Worked for 2 mins 22 sec

flux

Created the comprehensive PCB Engineering Takeover Report.

It covers:

Both project links and board responsibilities
Current CM5 and S32K344 architecture
Power, camera, radar, autopilot, Wi‑Fi, FHSS and SIYI interfaces
Board dimensions, stackups and enclosure direction
Completed fixes and verified checks
Routing-service failure and recovery history
Known footprints, software and regulatory risks
Recommended takeover sequence
Fabrication-release gates
Immediate first-day checklist and required engineer deliverables

The report clearly marks both boards HOLD for fabrication until routing, interface freeze, DRC, thermal, software and mechanical validation are complete.

Review takeover report

Audit live board states

Prepare migration package

Freeze external interfaces

Files

Schematic

Layout

3D View

Connector Pinout Matrix — KRYSTAL Module

Status: Draft v0.1
Scope: Preliminary connector and board-to-board signal allocation for the first KRYSTAL prototype.
Architecture basis: Two-board system: Board 1 compute/communications, Board 2 safety/navigation/payload I/O.

1. Connector Strategy

KRYSTAL should use rugged, locking external connectors and two internal high-reliability board-to-board connectors. Exact connector families are still TBD, so this matrix defines required signal groups before final mechanical connector selection.

Design principles:

Keep safety-critical flight-controller and payload I/O on Board 2.
Keep Ethernet, radio, USB service, and high-bandwidth compute interfaces on Board 1.
Let Board 2 own power sequencing, compute reset, actuator enable, and emergency release authority.
Split internal power and safety-critical interconnect across two board-to-board connectors so one connector is not a single point of failure.
Treat every external connector as an ESD, surge, EMI, and water-ingress risk point.

2. External Connector Summary

Table

ID	Name	Board	Preliminary pin count target	Primary role
J-A	Aircraft Power Input	Board 2 or power entry area	4 to 6	Main 9-36 VDC input and chassis/shield reference
J-B	Flight Controller 1	Board 2	8 to 10	Primary CAN FD, UART/MAVLink, sync, ground
J-C	Flight Controller 2	Board 2	8 to 10	Redundant CAN/UART and heartbeat input
J-D	Payload Bus	Board 2	12 to 16	CAN FD, RS-485, aux power, emergency line
J-E	External Ethernet	Board 1	8 plus shield	Rugged 100/1000 Ethernet link
J-F	Radar Head	Board 1 plus Board 2 control	10 to 14	Ethernet, sync, trigger, regulated radar power
J-G	USB-C Service	Board 1	USB-C standard	Service/debug/log extraction; bench power only if supported
J-H	RF Antennas	Board 1	2 to 4 coax	GNSS, swarm radio, optional LTE/5G/UWB
J-V1	Front Remote Camera	Board 1	TBD	Terminal-guidance remote camera link; prefer GMSL2 over coax/STP
J-V2	Down Remote Camera	Board 1	TBD	Downward optical-flow / VIO / GPS-denied remote camera link; prefer GMSL2 over coax/STP
J-I	Payload Actuators	Board 2	12 to 20	PWM, digital outputs, servo, winch command, feedback
J-J	Payload Sensors	Board 2	16 to 24	Load cells, analog sensors, limit switches, temperature
J-K	Debug/Factory	Board 2 and Board 1	TBD	Programming, SWD/JTAG, UART console, manufacturing test

3. J-A Aircraft Power Input

Recommended signals:

Table

Pin group	Signal	Direction	Notes
Power	VIN_9_36V	Input	Main aircraft power input; size for 65 W peak plus margin
Power	VIN_RETURN	Input	Power return; route with high-current path
Chassis	CHASSIS_SHIELD	Passive	Bond to enclosure strategy TBD
Sense optional	VIN_SENSE_PLUS	Input	Optional remote sense or diagnostic input
Sense optional	VIN_SENSE_RETURN	Input	Optional remote sense return
Key optional	POWER_PRESENT / ID	Input	Optional harness detect or coded input

Protection required near connector:

Fuse or eFuse.
Reverse-polarity protection.
TVS and surge suppression.
Inrush control.
Input current and voltage monitoring.
EMI filtering.

4. J-B Flight Controller 1

Schematic implementation added:

Table

Schematic connector	Part	Purpose	Pin allocation
J6	JST GH 4-pin BM04B-GHS-TBT	Autopilot CAN FD	1 = 5V_CAN_LOCAL / VREF accessory, 2 = CAN1_H, 3 = CAN1_L, 4 = GND
J7	JST GH 6-pin SM06B-GHS-TB	Autopilot MAVLink/TELEM UART	1 = 5V_CAN_LOCAL / VREF accessory, 2 = FC1_UART_RX_FROM_AUTOPILOT, 3 = FC1_UART_TX_TO_AUTOPILOT, 4 = CTS, 5 = RTS, 6 = GND

These connectors are intended to make KRYSTAL easy to connect to common PX4/ArduPilot-style flight-controller harnesses. Final harness validation must confirm the exact autopilot vendor pinout before first power-up. The 5 V pin is an accessory/reference rail, not a guaranteed autopilot main-power output; add connector current limiting/backfeed protection before using it to power external equipment.

Recommended signals:

Table

Signal	Direction	Board owner	Notes
FC1_CAN_H	Bidirectional	Board 2	Primary CAN FD high
FC1_CAN_L	Bidirectional	Board 2	Primary CAN FD low
FC1_UART_TX	Output from KRYSTAL	Board 2	MAVLink TX to flight controller
FC1_UART_RX	Input to KRYSTAL	Board 2	MAVLink RX from flight controller
FC1_UART_CTS	Input optional	Board 2	Hardware flow control
FC1_UART_RTS	Output optional	Board 2	Hardware flow control
FC1_SYNC	Bidirectional or input	Board 2	Time sync or PPS-style signal
GND_ISO_OR_REF	Reference	Board 2	Depends on isolation strategy
SHIELD	Passive	Enclosure	Cable shield termination strategy TBD

Recommendation: isolate CAN where practical; consider isolated UART if flight-controller ground offset is likely.

5. J-C Flight Controller 2

Recommended signals:

Table

Signal	Direction	Board owner	Notes
FC2_CAN_H	Bidirectional	Board 2	Redundant CAN FD high
FC2_CAN_L	Bidirectional	Board 2	Redundant CAN FD low
FC2_UART_TX	Output from KRYSTAL	Board 2	Redundant MAVLink TX
FC2_UART_RX	Input to KRYSTAL	Board 2	Redundant MAVLink RX
FC2_HEARTBEAT_IN	Input	Board 2	Independent flight-controller heartbeat/status
FC2_SYNC	Bidirectional or input	Board 2	Optional sync line
GND_ISO_OR_REF	Reference	Board 2	Depends on isolation strategy
SHIELD	Passive	Enclosure	Cable shield termination strategy TBD

6. J-D Payload Bus

Recommended signals:

Table

Signal	Direction	Board owner	Notes
PAYLOAD_CAN_H	Bidirectional	Board 2	Payload CAN FD high
PAYLOAD_CAN_L	Bidirectional	Board 2	Payload CAN FD low
PAYLOAD_RS485_A	Bidirectional	Board 2	RS-485 A
PAYLOAD_RS485_B	Bidirectional	Board 2	RS-485 B
AUX_12V_SW	Output	Board 2	Protected switched auxiliary 12 V
AUX_5V_SW	Output	Board 2	Protected switched auxiliary 5 V
AUX_RETURN	Return	Board 2	Return for aux power
EMERGENCY_LINE	Bidirectional or output	Board 2	Emergency inhibit/release signaling; exact polarity TBD
PAYLOAD_PRESENT	Input	Board 2	Harness/payload detect
SHIELD	Passive	Enclosure	Cable shield termination

Protection required:

ESD on CAN/RS-485 and digital lines.
Common-mode choke as needed for CAN/RS-485.
Current limiting on AUX_12V_SW and AUX_5V_SW.
Fault feedback to safety MCU.

7. J-E External Ethernet

Recommended signals:

Table

Signal	Direction	Board owner	Notes
ETH_TRD0_P/N	Bidirectional	Board 1	1000BASE-T pair 0
ETH_TRD1_P/N	Bidirectional	Board 1	1000BASE-T pair 1
ETH_TRD2_P/N	Bidirectional	Board 1	1000BASE-T pair 2
ETH_TRD3_P/N	Bidirectional	Board 1	1000BASE-T pair 3
ETH_SHIELD	Passive	Enclosure	Magnetics/shielding strategy TBD

Options:

Standard 1000BASE-T with magnetics on Board 1.
Rugged Ethernet connector or panel feedthrough.
Consider Ethernet switch if radar, service Ethernet, and external network are simultaneous requirements.

8. J-F External Radar Head

Implemented safety/base-board power/control connector (J9)

The base board now implements J9 as TE Connectivity DEUTSCH DT13-08PA, an 8-position sealed locking right-angle PCB header. Radar data remains on the compute-board Gigabit Ethernet path through J4/J3; J9 carries only protected power and low-speed safety/control.

Table

J9 pin	Net	Function
1, 2	`RADAR_PWR_SW_TBD_9_36V`	Protected/switched aircraft-bus pass-through; voltage/current TBD pending radar selection
3, 4	`GND`	Radar power/signal return
5	`RADAR_TRIGGER_3V3`	3.3 V trigger output through 100 ohm series resistor and ESD protection
6	`RADAR_TIME_SYNC_3V3`	3.3 V time-sync output through 100 ohm series resistor and ESD protection
7	`RADAR_STATUS_N_3V3`	Active-low/open-drain status or fault input, 10 k pull-up, 1 k input series resistor, ESD protected
8	`RADAR_PRESENT_N_3V3`	Active-low presence input, 10 k pull-up, 1 k input series resistor, ESD protected

U14 TPS26630 provides 1.5 A provisional current limiting, controlled startup, approximately 39.2 V OVP, IMON, fault and power-good feedback to S32K344, and safe default-off via a hardware pull-down on SHDN. D7 TPD4E05U06 protects all four exposed low-speed lines. Confirm final signal direction/levels and radar power requirements before cable release.

Recommended signals:

Table

Signal	Direction	Board owner	Notes
RADAR_ETH_Pairs	Bidirectional	Board 1	Ethernet data path; 100/1000 type TBD
RADAR_PWR_SW	Output	Board 2 power control / Board 1 routing TBD	Regulated switched radar power
RADAR_PWR_RETURN	Return	Board 2	Return for radar power
RADAR_SYNC	Bidirectional or output	Board 2 and Board 1	Time sync; voltage level TBD
RADAR_TRIGGER	Bidirectional or output	Board 2 and Board 1	Trigger/strobe; voltage level TBD
RADAR_FAULT	Input	Board 2	Optional fault or power-good feedback
RADAR_CAN_H	Bidirectional optional	Board 2	Optional CAN FD fallback
RADAR_CAN_L	Bidirectional optional	Board 2	Optional CAN FD fallback
SHIELD	Passive	Enclosure	Shield termination

Open decisions:

TI radar evaluation platform power voltage/current.
Ethernet type: standard 100/1000BASE-T vs automotive Ethernet.
Sync/trigger voltage levels and timing.
Whether radar power switching is physically on Board 1 or Board 2.

9. J-G USB-C Service

Recommended behavior:

USB data for software loading, logs, and debug access.
Bench power only if explicitly supported by the power architecture.
Not a primary flight power input.

Required USB-C signals:

Table

Signal	Direction	Board owner	Notes
USB_D_P	Bidirectional	Board 1	USB 2.0 data
USB_D_N	Bidirectional	Board 1	USB 2.0 data
USB_SS_TX/RX	Bidirectional optional	Board 1	Include if USB 3 is required
CC1 / CC2	Passive or controlled	Board 1	Role/attach detection; PD controller only if PD needed
VBUS_SERVICE	Input or sense	Board 1 / power system	Bench-power policy TBD
GND	Reference	Board 1	USB return
SHIELD	Passive	Enclosure	ESD and shield strategy required

10. J-H RF Antennas

Preliminary RF connector allocation:

Table

RF connector	Function	Board owner	Notes
RF1	GNSS antenna	Board 1	Active antenna bias optional
RF2	Swarm radio primary	Board 1	Module-dependent
RF3	Swarm radio diversity or LTE/5G	Board 1	Optional
RF4	UWB or LTE/5G secondary	Board 1	Optional

Mechanical requirements:

Keep RF routing short and controlled impedance.
Place connectors at enclosure edge with antenna cable bend-radius allowance.
Maintain antenna keepouts and isolation between radios.

10A. J-V1 / J-V2 Vision Camera Interfaces

Camera data is high bandwidth and belongs on Board 1 compute/vision, not Board 2 safety MCU.

Decision update: the front and downward cameras are mounted on the drone body, so J-V1/J-V2 should be rugged remote-camera links rather than direct long CSI-2 FFC cables.

Recommended first-prototype allocation:

Table

Connector	Role	Preferred interface	Notes
J-V1	Front camera	Preferred GMSL2 coax/STP	Terminal guidance / target acquisition; global shutter preferred
J-V2	Downward camera	Preferred GMSL2 coax/STP	Optical flow / visual odometry / landing aid; mono global shutter preferred

Because the cameras are remote from KRYSTAL, replace direct CSI-2 with a rugged remote-camera link:

Table

Remote-camera option	Board 1 signals	Camera-head signals	Notes
GMSL2 / GMSL3	Deserializer to CSI-2 compute input	Sensor + serializer	Good for compact remote cameras over coax/STP
FPD-Link III / IV	Deserializer to CSI-2 compute input	Sensor + serializer	TI ecosystem alternative for rugged camera heads

Typical direct CSI-2 signal groups, exact pinout TBD by compute SOM and camera connector:

Table

Signal group	Notes
CSI_CLK_P/N	Controlled-impedance differential pair
CSI_D0_P/N through CSI_Dx_P/N	Lane count depends on camera resolution/frame rate
CAM_I2C_SCL/SDA	Camera control bus; pull-ups on compute side if required
CAM_MCLK	Optional master clock if required by sensor/module
CAM_RESET_N / PWDN	Per-camera control lines
CAM_SYNC / TRIGGER optional	Needed for synchronized capture or timestamping
CAM_PWR rails	Sensor/module dependent; normally generated on compute/vision board
GND / shield	Multiple grounds around high-speed pins; shield strategy TBD

Remote-camera ecosystem decision: prefer GMSL2. Do not finalize J-V1/J-V2 connector pinout until the exact camera module, coax/STP connector, power-over-cable policy, and MAX9296A-to-serializer reference design are selected. The serializer and deserializer must match: GMSL2 parts do not interoperate with FPD-Link parts.

11. J-I Payload Actuators

Recommended signals:

Table

Signal group	Example signals	Direction	Notes
PWM outputs	PWM_OUT1 to PWM_OUT4	Output	Protected PWM outputs
Digital outputs	DIG_OUT1 to DIG_OUT4	Output	Protected digital outputs
Servo outputs	SERVO1_PWM, SERVO2_PWM	Output	Add 5 V servo power only if current budget allows
Winch control	WINCH1_FWD/REV, WINCH2_FWD/REV	Output	Prefer command interface to external high-current driver unless current is small
Output feedback	OUT_FAULT, OUT_CURRENT_SENSE	Input	Fault and current telemetry to safety MCU
Emergency release	RELEASE_ARM, RELEASE_FIRE, RELEASE_FB	Mixed	Final polarity and actuator type TBD
Power return	ACT_RETURN	Return	Keep high-current paths out of logic ground where possible

Rule: high-current winch and payload motor operating power should not flow through KRYSTAL PCB unless the final current is proven small and the PCB is sized accordingly.

12. J-J Payload Sensors

Schematic implementation added for first load-cell channel:

Table

Schematic connector	Part	Purpose	Pin allocation
J5	JST GH 6-pin SM06B-GHS-TB	Load-cell / cable-tension sensor	1 = LC_EXC_P / 3V3_AON, 2 = LC1_SIG_P, 3 = LC1_SIG_N, 4 = LC_EXC_N / GND, 5 = CHASSIS_SHIELD, 6 = LC1_ID_PRESENT

Table

AFE	Part	Notes
U10	ADS1232IPW	24-bit bridge-sensor ADC, gain 128, 10 SPS, internal oscillator, ratiometric 3.3 V excitation/reference for first prototype

Recommended signals:

Table

Sensor type	Signal allocation	Notes
Load cells	LC1 to LC4 differential pairs, excitation, shield	Four channels minimum; design expandable to eight
Analog 0-3.3 V	ANA_IN1 to ANA_IN4	Add filtering and overvoltage protection
Digital isolated inputs	DIN1 to DIN8	Limit switches, latch status, payload present
Frequency/pulse inputs	PULSE_IN1 to PULSE_IN4	Encoders, tachometer, pulse sensors
Temperature	TEMP_IN or 1-Wire/I2C optional	Exact sensor interface TBD
Payload IMU/GNSS	UART/I2C/SPI optional	Prefer external payload bus if sensor is remote

Precision note: use external load-cell ADC/AFE for cable tension. Do not depend on MCU internal ADC for precision load-cell measurement.

13. Internal Board-to-Board Connectors

Use two board-to-board connectors between Board 1 and Board 2.

B2B-A: Power and High-Current/Control Interconnect

Table

Signal group	Direction	Notes
COMPUTE_5V or COMPUTE_INPUT	Board 2 to Board 1	Compute input power; current rating TBD after SOM selection
COMPUTE_GND	Shared	Multiple pins required
COMPUTE_EN	Board 2 to Board 1	Safety MCU enables compute domain
COMPUTE_RESET_N	Board 2 to Board 1	Safety MCU can reset compute
COMPUTE_PGOOD	Board 1 to Board 2	Compute rail power-good feedback
RADAR_PWR_SW optional	Board 2 to Board 1/J-F	If radar power switch is located on Board 2
AUX_FAULTS	Board 2 to Board 1 optional	Telemetry to compute
CHASSIS_REF optional	Shared	EMI/shielding strategy TBD

B2B-B: Data, Watchdog, and Safety Interconnect

Table

Signal group	Direction	Notes
COMPUTE_HEARTBEAT	Board 1 to Board 2	Linux liveness signal to safety MCU
SAFETY_STATUS	Board 2 to Board 1	Safety state summary
SAFETY_FAULT	Board 2 to Board 1	Fault/interrupt line
HOST_SPI or HOST_UART	Bidirectional	Main command/telemetry link between compute and safety MCU
HOST_CAN optional	Bidirectional	Optional compute-to-safety CAN path
TIME_SYNC	Bidirectional	Timebase alignment for logs/sensor fusion
EMERGENCY_INHIBIT_STATUS	Board 2 dominant	Compute can read; safety owns control
DEBUG_UART	Bidirectional	Development console path
BOOT_MODE / RECOVERY	Mixed	Manufacturing/service support
SPARE_GPIO	Mixed	Reserve at least 8 spare lines

Redundancy recommendation:

Put at least one heartbeat/status path and one ground reference on each connector.
Do not place every safety-critical signal on a single connector.
Use multiple ground pins adjacent to high-speed or noisy signals.

14. Initial Net Naming Convention

Use explicit prefixes so schematic pages remain readable:

Table

Prefix	Meaning	Example
VIN_	Raw or protected aircraft input	VIN_9_36V
SYS_	Regulated system rails	SYS_5V, SYS_3V3
SAFE_	Always-on safety domain	SAFE_3V3, SAFE_WDOG
CMP_	Compute-domain signals	CMP_RESET_N, CMP_HEARTBEAT
FC1_ / FC2_	Flight-controller links	FC1_CAN_H
PAY_	Payload bus or payload I/O	PAY_CAN_H, PAY_RS485_A
RAD_	Radar connector signals	RAD_TRIGGER
ACT_	Actuator outputs	ACT_PWM1
SNS_	Sensor inputs	SNS_LOADCELL1_P
B2B_	Board-to-board reserved names	B2B_TIME_SYNC

15. Open Connector Decisions

Before schematic capture is frozen, decide:

Final connector families and mating harnesses.
Required connector IP rating and sealing strategy.
Cable shield termination method.
Whether flight-controller interfaces are galvanically isolated.
Exact radar electrical interface and power requirement.
Exact load-cell count and connector allocation.
Whether actuator connectors carry power or only command/feedback signals.
Emergency-release actuator type, current, polarity, and feedback method.
Whether external Ethernet and radar Ethernet require an onboard switch.
Compute SOM final choice and exact carrier connector pinout.
Front/down camera mechanical placement, cable length, interface type, and selected camera module connector pinout.
Whether KRYSTAL needs a direct safety-radio receiver input connector, or whether RadioMaster TX16S receiver state is observed only through the autopilot. If direct input is required, select receiver protocol: SBUS, CRSF, Spektrum serial, PWM, or UART.
Whether the SIYI HM30/MK32 tertiary data/video link connects to KRYSTAL directly over Ethernet, through the autopilot/GCS network, or only to the camera payload/ground unit. If direct, reserve an Ethernet/network connector or switch port and define IP subnet/addressing.
Reference drone uses Pixhawk/autopilot integration; maintain easy Pixhawk-style CAN and TELEM/MAVLink connector mapping and verify exact pinout before first power-up.

16. Recommended Next Schematic Start

Start schematic capture in this order:

J-A aircraft power input and protection.
Always-on safety regulator rail.
NXP S32K344 safety MCU core, reset, clock, debug, watchdog.
J-B and J-C flight-controller CAN/UART interfaces.
B2B-A and B2B-B board-to-board interconnect symbols.
J-D payload bus and basic protection.

This lets KRYSTAL establish the safety and power backbone before the compute SOM connector is finalized.

1. Connector Strategy
2. External Connector Summary
3. J-A Aircraft Power Input
4. J-B Flight Controller 1
5. J-C Flight Controller 2
6. J-D Payload Bus
7. J-E External Ethernet
8. J-F External Radar Head
Implemented safety/base-board power/control connector (J9)
9. J-G USB-C Service
10. J-H RF Antennas
10A. J-V1 / J-V2 Vision Camera Interfaces
11. J-I Payload Actuators
12. J-J Payload Sensors
13. Internal Board-to-Board Connectors
B2B-A: Power and High-Current/Control Interconnect
B2B-B: Data, Watchdog, and Safety Interconnect
14. Initial Net Naming Convention
15. Open Connector Decisions
16. Recommended Next Schematic Start