Full DIN EVCC message field tree + Cadillac Lyriq baseline

[JakeMG-INL]

What to build

Source all EVCC-emitted DIN messages from the [[message field tree]], and ship the default din-evcc baseline replicating the Cadillac Lyriq from ABB_Cadillac_Lyric.pcapng field-for-field. Mirrors the SECC slice (#73) for the vehicle side; can run in parallel with it once #72 lands.

Every EVCC-emitted DIN message reads its fields from the tree: SessionSetupReq, ServiceDiscoveryReq, ServicePaymentSelectionReq, ContractAuthenticationReq, ChargeParameterDiscoveryReq, CableCheckReq, PreChargeReq, PowerDeliveryReq, CurrentDemandReq, WeldingDetectionReq, SessionStopReq. Retire the structured ev_dc reads in the DIN EVCC path.

Key Cadillac baseline values (full decode reference in session scratchpad din_baseline_ABB_Cadillac.md): SAP offers DIN only (SchemaID 1, Priority 1); ServiceDiscoveryReq ServiceCategory EVCharging; ServicePaymentSelectionReq ExternalPayment / ServiceID 1; ChargeParameterDiscoveryReq EVRequestedEnergyTransferType DC_extended, DC_EVStatus SOC 88 / NO_ERROR, EVMaximumCurrentLimit 500 A, EVMaximumVoltageLimit 410 V, FullSOC 100, BulkSOC 80; PowerDeliveryReq BulkChargingComplete true; CurrentDemandReq EVMax V 410 / A 500, RemainingTimeToFullSoC 2111. Runtime/computed fields (SessionID, EVCCID from NIC, present/target voltage & current as they ramp, EVReady) stay computed/start-value, not static baseline.

Acceptance criteria

• All EVCC-emitted DIN messages are tree-sourced; structured ev_dc reads removed from the DIN EVCC path
• din-evcc baseline emits every EVCC DIN field matching ABB_Cadillac_Lyric.pcapng (verified by decoding the emulator's wire output against the pcap)
• Virtual two-session DIN demo completes cleanly with din-evcc against din-secc (Full DIN SECC message field tree + ABB charger baseline #73)

Blocked by

• Per-role personality split + residual section + migration scaffolding #72

[JakeMG-INL]

Implementation summary (agent, 2026-07-01)

Branch / base: development @ b1278fb
Files touched:

• app/evcc/evcc_config.py — carry message_field_tree through EVCCConfig.from_personality (the seam the EVCC DIN states read).
• app/evcc/controller/simulator.py — retire the DIN ev_dc structured reads: the DIN branch of _build_dc_ev_charge_params sources the announced maxima + capacity from EVDCLimits() model defaults (tree-owned on the wire); get_remaining_time_to_* do the same for DIN. Target V/A stay config-sourced (the ramping carve-out). ISO-15118-2 unchanged.
• app/evcc/states/din_spec_states.py — new apply_personality_tree() helper (vehicle-side mirror of the SECC Full DIN SECC message field tree + ABB charger baseline #73 helper) applied at every EVCC-emitted DIN *Req build site; CurrentDemandReq no longer emits EVMaximumPowerLimit on DIN (the Cadillac omits it).
• app/evcc/states/sap_states.py — route the DIN SessionSetupReq through the tree too.
• personalities/din-evcc-baseline.yaml — full Cadillac Lyriq message_field_tree (ServiceCategory EVCharging; ExternalPayment/ServiceID 1; CPDReq 500 A / 410 V, FullSOC 100, BulkSOC 80, SOC 88; PowerDeliveryReq BulkChargingComplete; CurrentDemandReq 410 V/500 A, RemainingTimeToFullSoC 2111, RemainingTimeToBulkSoC 0; SOC 88 pinned per message).
• personalities/din_dc_extended-evcc.yaml — collapsed to a thin extends: + EVCCID + target start values (mirrors the SECC din_dc_extended-secc collapse); the retired maxima/remaining-time fields removed.

Tests added:

• tests/conformance/state_machine/evcc/test_din_cadillac_baseline.py — drives the real EVCC states through a full DIN session, decodes each outbound *Req, asserts every Cadillac field.
• tests/conformance/e2e/test_din_cadillac_baseline_wire.py — real two-subprocess DIN session (Cadillac EVCC vs ABB SECC) over veth with the capture tap; decodes the EVCC wire *Reqs and asserts the pcap values (acceptance Make AcCCS usable with different hardware setups #2 + Open-source contributions from Ford #3).
• tests/personality/test_din_slice.py — rewrote the old "DIN uses ev_dc limits" test into a retirement test + an ISO-2-still-uses-config test + a tree-sourced CurrentDemandReq test.

Verify: PASS — full suite 819 passed / 5 skipped (non-E2E); all 22 E2E pass. The new E2E drives the live two-session DIN demo to clean completion and confirms ChargeParameterDiscoveryReq (500 A / 410 V, FullSOC 100, BulkSOC 80, SOC 88, no power limit) and CurrentDemandReq (410 V / 500 A, remaining 2111/0, bulk complete, no power limit) on the wire.

Decisions made:

• Threaded the tree through EVCCConfig rather than attaching the whole personality to SimEVController — the EVCC is config-driven (unlike the SECC, which holds the personality), and the states already read comm_session.config.
• EVRESSSOC pinned to 88 per message: the issue lists it as a baseline value and excludes it from the computed-fields list; the capture shows a static 88 %. Internal _soc still ramps to drive loop termination — the tree only pokes the wire value.
• capabilities.energy_transfer_mode (dual-purpose EVRequestedEnergyTransferType) left single-sourced in capabilities, not duplicated into the tree — its tree migration is a later slice per the baseline stub note and CLAUDE.md.
• EVMaximumPowerLimit dropped from the DIN CurrentDemandReq builder (the tree can override a field but not remove one) to match the capture, which omits it.

Open caveats: SessionSetupReq (EVCCID from NIC) and ContractAuthenticationReq (empty) are routed through the tree helper for completeness but carry no baseline leaves — the capture leaves both computed. The capture starts mid-CurrentDemand for the first TCP session and never reaches WeldingDetection/SessionStop, so those Reqs (SOC 88 only) are matched against the DC_EVStatus pattern, not a captured frame.

[JakeMG-INL]

Landed in 1c6a5cf on development.

Sourced the whole DIN EVCC path from the message field tree and shipped the Cadillac Lyriq baseline; the announced ev_dc maxima are retired from the DIN wire.

Manual verification: full non-E2E suite (819 passed / 5 skipped) + the DIN Cadillac E2E wire test driving a clean two-session demo and asserting the pcap values on the wire (CPDReq 500 A / 410 V, FullSOC 100, BulkSOC 80, SOC 88, no power limit; CurrentDemandReq 410 V / 500 A, remaining 2111/0, bulk-complete, no power limit).