SENT¶

Unidirectional digital sensor interface for automotive sensors.

Identity¶

Unidirectional digital sensor interface for automotive sensors.

What This Protocol Teaches¶

• Not every important vehicle signal is on a network; some are private sensor monologues.
• It teaches how to inspect sync pulse, nibbles, status/CRC nibble without mistaking field extraction for meaning.
• It keeps observer inference separate from system truth.

Operational Context¶

SENT / SAE J2716 appears in automotive, sensor-link contexts and is modeled in the atlas at the physical, data-link layer(s). The binder treats it as an inspection surface: what evidence appears, what timing matters, and what outside authority is required before assigning meaning.

draft-structure-only: this is not yet a final-copy binder page. It has an atlas-grounded teaching hook and source notes, but still needs a stronger worked trace, page-specific ambiguity case, and reviewer-validated visual before promotion.

A Concrete Artifact¶

# synthetic SENT frame
sync=56 ticks status=1 nibbles=3 a 7 0 5 crc=c

Synthetic offline sample for explanation; not a real operational trace or live-system instruction.

Worked Decode¶

1. Read sync=56 ticks as the timing reference for this synthetic SENT frame.
2. status=1 and nibbles=3 a 7 0 5 are nibble evidence before any sensor-specific scaling.
3. crc=c is frame-integrity evidence, not physical measurement truth.
4. Tick timing and sensor profile are required before interpreting the nibble stream as engineering state.

Field Layout / Anatomy¶

Visual Model¶

Timing And Authority¶

Timing and authority depend on the sensor-interface role: scheduled, polled, arbitrated, transmitted, or logged evidence should not be read as the same kind of truth. Semantic authority is external to the raw artifact unless the artifact is itself a description or capture format; even then, provenance determines whether the description should be trusted.

Bytes rarely explain themselves. Name the source that defines meaning before naming engineering values: standard metadata, label table, DBC, PGN/SPN definition, object dictionary, register map, DID catalog, LDF, ARXML, channel metadata, or vendor profile.

Failure And Ambiguity¶

• Nibble values are not measurements until a sensor profile defines scale and status.
• Tick timing errors can make a frame look syntactically plausible but wrong.
• A correct CRC does not prove physical truth.

Observer Lesson¶

A passive observer can usually infer artifact boundaries, repeated structure, cadence, missingness, and candidate state transitions. The observer usually cannot prove physical truth, application intent, complete system state, or engineering-unit meaning without semantic authority and timing provenance.

Python Model¶

No current runtime example is claimed for this draft page. Keep reader claims at the artifact and source level until a separate implementation plan adds a tested model.

Local Teaching Notes¶

The artifact and diagrams are synthetic teaching material. The page intentionally omits conformance timing tables, electrical design detail, proprietary configuration, and exhaustive standard behavior.

Source Confidence¶

Source confidence is high for scope and terminology, with semantic claims limited to public metadata, public source notes, and synthetic teaching artifacts.

Source Notes¶

References¶

Public Sources¶

• SAE International
• SAE J2716 SENT — Single Edge Nibble Transmission for Automotive Applications — canonical-standard.
• Texas Instruments
• Multi-Channel SAE-J2716 SENT Decoder — vendor application note.