Final dispositions from the Snowball schematic-review meetings (captured from docs/DOC-00000507/Meeting Notes for Snowball.docx). Carried forward as design constraints for any future revision/test development.

• Vn pull-up = keep 3K3 (spec value). Rationale: up to four boards may stack → four 3K3 in parallel ≈ 825 Ω; both end values must work and be covered in verification. Switches added to enable up to 3× 3K3 in parallel. Rejected: changing to 1K to match the old test board (spec governs).
• VRP/VRN pull-down test — dropped on Snowball. No access to the MB pull-down resistors; only existence of VRP/VRN is checked. Treated as regular inputs with pull-down.
• uFPGA DAC Vref verification — dropped on Snowball. VREF is realized differently per motherboard and does not route to Snowball; keep only generic tests. Must be tested in cFPGA instead.
• JTAG port required. Although bFPGA can be programmed via I2C (preferred in production), a dedicated JTAG port is kept for Snowball production tests because it is more robust.
• Add real GND + short PRESENCEn to GND (add real ground on pin 144/146, ground the presence pin) to guarantee a good negative reference and non-ambiguous start-up.
• HT3 LED test accepted (bonus feature) using optical sensor APDS-9306-065 (original candidate MAX44007/009 discontinued).
• D10 (DONE LED) = no-mount on production boards; populated only during Snowball-only verification to keep the board single-sided (cost).
• 3 vs 6 HT3 versions, interposer vs direct — deferred (decision to come later).

Decision (2026-06-04, daniel@esharp.se): E-Sharp is not designing the Snowball board — we only use it in our test development. Board design and its requirements belong to Synopsys.

Actions taken:

• Removed the 8 board-design functional requirements (former REQ-001..008: HT3 open/short detection, HapsTrak-3 std compliance, all-pins-verifiable, pin-ID granularity, JTAG header, no inter-connector dependency, VCCO-change, LED test). These describe Synopsys's board design, not E-Sharp deliverables. Board reference info is retained in [[imported-design-baseline-snowball]] and [[schematic-review-final-decisions]].
• Dropped the electronics discipline (now test only). This removes the electronics design rules that were inherited — SYS-CL-001/002/003 (component-lifecycle / no-EOL-parts / discontinued-part-replacement) — which only apply to design ownership.

Retained: the generic test-system requirements (REQ-TS-001..006) and test/verification design rules (SYS-LM, SYS-SF, SYS-SO, SYS-TR, SYS-VA, SYS-VF), which govern E-Sharp's test-development rigor.

A software driver for the Snowball CPLD GPIO expander has been implemented in the AccordionQ2 hardware-manager codebase (branch upgrade-to-NET10). See the concept note "Snowball AccordionQ2 Driver — Concept Note" (knowledge doc #18) for the full design.

What was built (two layers)

• SnowballCpld (submodules/devicelibrary/Devices/GPIO/Snowball/SnowballCpld.cs) — a reusable GpioExpander / II2cDevice at I²C 0x41, generic over N ports, implementing the CPLD CMD,PORT,Data codec (0xFF reset, 0x03/0x04 data, 0x05/0x06 tristate, 0x07 burst read, 0x08 register read, 0xF0 design ID). Reuses the existing GpioExpander/GpioBank caching/diffing scaffolding (bit conventions match: tristate 1=input = Configuration, data = Value).
• Snowball module (Extensions/Snowball/) — IAdditionalModule + IBusHandler that hosts the device, exposes all 162 named GPIO signals from the GPIO Signal Mapping (knowledge doc #17) as digital channels, and owns the PCA9547 0x70 connector mux (control byte 0x08 | channel; CH1=J1/CH2=J2/CH3=J3). It contains the Snowball control logic only — physical I²C is delegated to the bus-owning module via the established I2CTransactionPath → ModuleParent.TransactValue pattern (same as PmbusEngine/Pmbus.cs).

Deployment

• Added to the solution, the deploy build/copy pipeline (deploy-all-to-pi.ps1, postbuild.ps1), and modules.config.
• On agent64.local, a Snowball entry was added to modules.config with I2CTransactionPath = 1.MicroHAPS.HCI.2|I2cMasterMux.I2C1 (the I²C bus is provided by the MicroHAPS module). Currently Enabled: false.

Status / open items

• Builds clean; not yet exercised on hardware.
• The Snowball DLL must be shipped via a full deploy before the agent64 entry can be enabled.
• Mux part confirmed as PCA9547 (datasheet docs/PCA9547.pdf in the microHAPS repo); a MuxType config override exists for a PCA9545/9548-class bitmask-switch variant.

Discipline: this is E-Sharp test-development work using the Synopsys-owned Snowball board; the board design remains out of scope.

Extends the AccordionQ2 Snowball driver (see entry E-005 and concept note #18) with support for the Snowball board's APDS-9306-065 ambient light sensor at I²C 0x52, behind the same 0x70 PCA9547 mux as the CPLD.

What was added

• APDS9306 device (submodules/devicelibrary/Devices/LightSensor/APDS9306.cs) — ChannelCapableDevice / II2cDevice, sibling to the existing VEML7700. Configurable gain (1/3/6/9/18×), resolution/integration time (20-bit/400 ms … 13-bit/3.125 ms) and measurement rate; checks PART_ID (expects 0xB3); reads the 20-bit ALS value and computes lux = (raw / gain) × (100 / integration_ms) × LuxFactor. Register map/formula taken from the Broadcom datasheet (AV02-4755EN), cross-checked against an open-source driver.
• Snowball module now hosts both the CPLD and the sensor, exposing two read-only analog channels — OPT_ALS (raw 20-bit counts) and OPT_LUX (normalised light level). Sensor access is wrapped in the existing mux selection (a single mux selection covers a combined CPLD + sensor refresh).
• Sensor settings exposed via modules.config InitialData: SensorAddress, SensorGain, SensorResolution, SensorMeasRate, SensorLuxFactor.

Builds clean; not yet exercised on hardware.

Open items

• EEPROM (0x50) support is still pending — awaiting the content spec from the user.
• SensorLuxFactor defaults to 1.0 (output = gain/integration-normalised counts). The true lux scale for the -065 optical window should be set once the calibrated factor is known; until then OPT_ALS raw counts are the unambiguous reading.

Added a reusable codec for the Synopsys IDPROM content structure to DeviceLibrary: submodules/devicelibrary/Devices/Eeprom/SynopsysIdprom.cs (namespace DeviceLibrary.Devices.Eeprom). Ported faithfully from AccordionTS/Idprom.cs in the esharp-accordion-projects-accordionwrapper repo so it can be reused across projects.

This is the content layout of the Snowball board EEPROM at I²C 0x50 (the structure previously flagged as "pending" in entry E-006). It is the Synopsys format — deliberately distinct from E-Sharp's own IDPROM (handled by Identity), since both live at 0x50 on different boards.

Structure (255-byte image, total 0xFF)

• 0x00 DataStructureRevision (0x01) · 0x01–0x02 VendorCode (UInt16 big-endian) · 0x03–0x04 ProductCode · 0x05 VersionCode · 0x06 SubVersionCode · 0x07 ConnectorNumber · 0x08 SupportedVoltages (IoVoltages flags) · 0x09–0x0F reserved
• 0x10–0x23 ProductName (20 ASCII) · 0x24–0x2F ProductId (12 ASCII) · 0x30–0x3F SerialNumber (16 ASCII) · 0x40–0xFE BoardSpecificData (191 bytes)

Provides AsByteArray() / FromByteArray() / Compare(other, skipFields…) / ToString() and constructors for build-from-fields or parse-from-bytes. The byte layout (incl. the asymmetric serial-number handling — written as 16 ASCII bytes, read back as a 1-char code + 15-digit number) is preserved exactly as a hardware contract. Builds clean.

Remaining EEPROM work (not yet done)

• An I²C EEPROM device (read/write the 0x50 part, e.g. like ID_24AA02UID) and wiring it into the Snowball module to expose the decoded IDPROM fields as channels, behind the existing 0x70 mux.

Completes the Snowball EEPROM work flagged in E-006/E-007. The Snowball module now reads the board's Synopsys IDPROM (EEPROM at 0x50, behind the 0x70 mux) at Reset and exposes three read-only register channels (direction = IN): ProductName, SerialNumber, ProductId.

Implementation

• At Reset(), under a single mux selection, the module reads the IDPROM header block (bytes 0x00–0x3F, enough for the three fields), parses it with SynopsysIdprom (the reusable codec from E-007), and bakes the decoded values into three RegisterChannels grouped under "IDPROM".
• The read is best-effort: a missing/unreadable IDPROM logs a warning and yields blank fields rather than aborting module load.
• Scope intentionally limited per request: no write path, no full-content dump — only the three identity fields. Values are read once at Reset (board identity is static).
• New optional config EepromAddress (default 0x50) in modules.config InitialData.

Builds clean; not yet exercised on hardware. With this, all three Snowball-board I²C devices (CPLD GPIO, APDS-9306-065, IDPROM) are supported by the AccordionQ2 driver.

Refactor of the APDS-9306-065 configuration (refines E-006). The sensor's runtime settings no longer live in modules.config InitialData; they are now settable channels on the Snowball module:

• SensorGain, SensorResolution, SensorMeasRate → MultiplexerChannel dropdowns; options come from the APDS9306 enum names; selecting a value re-applies it to hardware via sensor.Reset() under the mux.
• SensorLuxFactor → RegisterChannel (free numeric value). LuxFactor is a continuous calibration multiplier (lux per normalised count) — not bounded 0–1 and not a discrete set, so a free value is correct rather than a RatiometricChannel (0–1/%) or MultiplexerChannel (discrete). It is a software-only scale (no register write).

Only the device addresses remain static config: InitialData now carries I2CTransactionPath, MuxAddress, MuxType, MuxChannel, CpldAddress, SensorAddress, EepromAddress. The four Sensor* runtime keys were removed from the repo modules.config.

Builds clean. Not yet deployed — the on-target agent64 DLL + modules.config still carry the old form and need a redeploy + config re-sync to match the repo.

This PLEASE project (ETT00000010 R0) imports an existing Synopsys design rather than a fresh design.

Identity

• Internal name: Snowball; formal name TEST_HT3_V2
• PCBA part number: SH100002584 — "Snowball_Test_HT3 PCBA", board rev R0.2 (per Omnify/Empower PackageReport)
• Implementation spec: DOC-00000274, spec rev R1.0 (2019-10-23, Li Xie)
• Controller (bFPGA): Lattice MachXO3 LCMXO3LF-9400C-6BG256C (256-ball caBGA, 206 I/O, 2× I2C hard cores)

Purpose: A test board that detects open and shorted pins on HapsTrak-3 (HT3) connectors of HAPS systems. Supersedes the earlier "TEST_HT3" board, fixing 6 known issues (screw-hole placement vs HT3 std, VCCO 2.5↔3.3 V negotiation clamp, 2-FPGA-for-3-connector partitioning, cross-connector Vn measurement ambiguity, mandatory middle connector, untestable GND pin 136).

Docs in repo docs/ (Omnify export): DOC-00000507 (spec + meeting notes), DOC-00000510 R1.1 (parts list/BOM), DOC-00000511 R0.1 (schematic), DOC-00000512 R1.1 (assembly spec), DOC-00000513 R0.0 (ODB++), DOC-00000514 R0.0 (GenCAD netlist).

Note the document/board revisions predate this PLEASE record; tracked here as R0 for E-Sharp's test-development engagement.

Open follow-ups from project setup (2026-06-04):

• IP sensitivity — Snowball design data (BOM, schematic, ODB++, GenCAD) is Synopsys-origin and may be confidential, like the sibling microHAPS project (ETT00000008) whose design docs are marked SYNOPSYS CONFIDENTIAL. Project was created with ipSensitive=false; recommend confirming whether it should be set true and whether the BOM may be imported into the shared PLEASE component library.
• BOM / netlist ingest — deferred. docs/ contains the parts list (DOC-00000510 R1.1), GenCAD netlist (DOC-00000514 R0.0) and ODB++ (DOC-00000513 R0.0), not yet ingested into the component library / netlist. Gate on the IP decision above.
• Verification plan — deferred. Template seeded 6 generic test cases (TC-TS-001..006) + a plan; a spec-driven plan (HT3 open/short, pin-group ID, VCCO-change, LED optical-sensor) via please_plan_suggest is not yet drafted.
• Design rules — only the 16 template-applied rules are active; the 4 suggested green-gate rules (SYS-VF-001/003, SYS-VA-001, SYS-TR-001) were not added.

See [[imported-design-baseline-snowball]] and [[schematic-review-final-decisions]].