2026-09-27 Air Hub platform combinations with device grades below the family temperature rule

• status: active
• date: 2026-09-27
• sunset: 2027-03-31
• deviates from: bizplan/governance/product-plan.md §1 family rule (−25…+70 °C operating) for the Air Hub combinations whose SoC is rated −20 °C minimum (H1–H6 in P05-air-hub.md §2.2), and the thermal margin assumed for the 60 °C compartment design (H6 +80 °C, H7 +75 °C)
• relatedTask: 20260927-1640-air-hub-low-cost-linux-and-lora-star

Context

Until R0.6 the Air Hub spec required an industrial −40…+85 °C Linux SoC with a native CAN controller (reference RK3506J). On 2026-09-27 the owner asked for as many hardware combinations as possible, including SSD202D with the ESP32-C6 as CAN controller, allowed the device grade to relax to about −20…+80 °C, dropped the native-CAN requirement, and stated that all host software will be written in Rust. The cheapest SoCs with in-package DRAM (SSD202D, RV1103, RV1106, RK3506G2) are rated −20 °C minimum; relaxing the grade brings no saving for platforms with external DRAM, because commercial DDR3L stops at 0 °C.

Decision

P05-air-hub.md R0.7 defines platform, CAN-source and radio axes and 30 named combinations instead of one reference platform. Combinations H1–H6 keep a SoC rated −20 °C minimum: they meet the product's own −20…+60 °C environment target (GW-05) but not the family −25 °C lower bound. H6 (+80 °C) and H7 (+75 °C) must prove their margin by a 60 °C ambient thermal test (guide V-07). The industrial combinations (H9–H14) remain available and satisfy the family rule.

Consequences

Easier: the Air Hub BOM can fall to about $18–38 before the SoC price for SSD202D-based combinations and about $26–38 for RV1106G3, and chip-down QFN parts avoid DDR routing. Harder: a combination in H1–H6 cannot claim the family temperature range; sales and installation material must state −20 °C; any vessel stored powered below −20 °C is out of scope. At the sunset date, or when AIR-O-03 selects a combination, close this record if an industrial combination is chosen, or amend the family rule for Air Hub if a −20 °C combination is chosen.

Amendment 2026-10-06

The owner moved the entry Air Hub (AH-19) from RV1106G3 chip-down to an SSD2351 stamp-hole core board (platform H15, MYZR-SSD2351-CB112), after the LCSC price of RV1106G3 rose from $5.56 @100 to $22.67 @30. The core board is rated −20…+70 °C by its vendor; the chip's own grade is not yet confirmed in writing. This record now also covers H15: the −20 °C lower bound is below the family rule as for H1–H6, and the +70 °C upper bound leaves no margin at the 60 °C compartment design point once the 10–15 °C enclosure rise is added. Until a written chip grade and the V-07 thermal test show margin, sales and installation material for Air Hub must not claim +60 °C ambient; the alternative is to derate the entry product's upper environment limit. Air Hub Pro (H12) is unaffected.

Amendment 2026-10-12

The owner dropped the SigmaStar platforms (H1, H2, H15) and locked the entry Air Hub (AH-19) on an RK3506G stamp-hole core board (platform H17, Vanxoak HD-RK3506G-128F256LW, 128 MB + 256 MB NAND). The core board is rated −20…+70 °C and the chip −20…+80 °C, so this record now covers H17 on the same terms as H15 did: the −20 °C lower bound is below the family rule, and the +70 °C upper bound leaves no margin at the 60 °C compartment design point until the V-07 thermal test shows it. Air Hub Pro (H12, RK3506J, −40…+85 °C) and Air Hub Mini (H16) are unaffected.

Amendment 2026-10-14

The Vanxoak HD-RK3506G-128F256LW data sheet rates the core board −20…+80 °C, not −20…+70 °C as recorded on 2026-10-12. H17 keeps the −20 °C lower-bound deviation; the upper bound now leaves 5–10 °C at the 60 °C compartment design point, still to be shown by the V-07 thermal test. The core boards are fixed to Vanxoak HD-RK3506G-128F256LW (Air Hub) and HD-RK3506J-256F256LI (Air Hub Pro).