dfrobot Gravity: Digital 10A Relay Module

AI context

Dense context for pasting into a model prompt — addresses, pinout, voltages, tolerances and the vendor's reference circuit.

PART: DFRobot Gravity: Digital 10A Relay Module, SKU DFR0473, 38 x 33 x 20 mm, 20 g. A single 3 V electromechanical relay on a Gravity carrier with an onboard state LED, a Gravity 3-pin digital input and a screw terminal broken out as NC, NO and COM. DFRobot publishes no relay part number on the product page, the wiki or the module datasheet, so part is null rather than guessed.
I2C ADDRESSES: none. The module has no bus at all - the only connection is one digital control line - so buses is empty and addresses is empty.
PINOUT: DFRobot's own pinout table numbers seven positions. 1 '-' = GND, 2 '+' = VCC (2.8-5.5 V), 3 'D' = control signal, 4 'NC' = normally closed contact, 5 'NO' = normally open contact, 6 'N/A' = empty terminal, 7 'COM' = common port. Pads 1-3 are the Gravity 3-pin input side; pads 4-7 are the switched side, and pad 6 is deliberately blank so the terminal prints NC and NO on either side of COM.
SUPPLY: 2.8 V to 5.5 V on VCC, so it runs off a 3.3 V or a 5 V rail. Input signal thresholds are given by DFRobot as high >= 2.8 V and low <= 0.5 V, which a 3.3 V GPIO clears comfortably and a 1.8 V part does not.
CONTACT RATING: max switching current 10 A; max switching voltage 35 VAC / 30 VDC; rated load 10 A @ 35 VAC and 10 A @ 28 VDC; max switching power 300 W; operate time <= 10 ms; release time <= 5 ms. The contact is a bare relay contact with hobby-grade terminal spacing, so it is not a mains isolation barrier.
REFERENCE CIRCUIT: nothing external is needed on the control side - DFRobot specifies a logic-level input with its own thresholds rather than a coil current, and the state LED is on the board. Nothing is specified about the coil driver, so no external component values are recorded.
TRAPS: (1) DFRobot's datasheet table gives mechanical life as 1 million operations and electrical life as 50 thousand, while the product page prose claims 'up to 100 million mechanical uses' - all three numbers are recorded and none is resolved. (2) At 10 ms operate and 5 ms release the contact cannot follow PWM, so this is on/off switching only. (3) Pad 6 is an empty terminal, not a second COM - wiring into it does nothing.