F1 controller and sensor boards; FRDM-IMX95; i.MX93 Linux e-ink; i.MX8M Mini active-screen; RT1170 battery e-ink. Individual harness profiles must define voltage, current, polarity, connector pinout, boot/reset wiring and all possible back-power paths. Existing board specifications support the first-pass BOM; physical checks remain later acceptance gates.
One external J-Link is shared among targets. Support keyed ARM/J-Link 20-pin IDC, 2x10 at 2.54 mm pitch, with adapters for the existing fixture. Pin 19 probe power is disconnected. Boot/ISP control is separate. Support programming, debugging and RTT console I/O through appropriate J-Link-compatible host tools. Switching must disconnect first, select one target only, settle, then attach the debugger. Shared-probe gang programming is sequential, not simultaneous; RTT/debug sessions cannot continue on deselected targets. VTref, supported voltage ranges, signal directions, speed and powered-off behaviour require qualification.
Each port may be used for power cycling without debug. Harnesses must support remotely connecting/disconnecting batteries and provide power-consumption measurement access. Distinguish main-feed cycling from verified full-off: other feeds, USB, debug pins and batteries can keep a target powered. Reject a new power-on that exceeds the declared supply budget without shedding already running targets. Overload and thermal faults latch off and require explicit retry; firmware must retain fault state when hardware latch reset paths would otherwise clear it.
Support remote boot-mode/ISP and reset control, including suitably verified replacement or bypass of development-board DIP switches. Never assume these are ordinary logic outputs: qualify contact topology, voltage and safe defaults per target.
Uniform 1/2/4-port population options, clearly labelled keyed harness connectors, optional functions separable by population, test points, service access and a printable enclosure. Management remains available independently of switched target power.
Use Zephyr on a suitable NXP MCXN device. Host software supports Linux/Windows, stable device/port identities, machine-readable commands/results, documented errors, explicit fault recovery and bounded operations suitable for an AI harness. Protocol details and ownership/interlocks remain design work.
Fully assembled units must be factory verified with a documented fixture and acceptance procedure. No purchases or manufacture are implied by this baseline.