dfrobot Gravity: HUSKYLENS with Silicone Case

AI context

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

PART: DFRobot Gravity: HUSKYLENS with Silicone Case, SKU SEN0305-S - the SEN0305 HuskyLens K210 AI vision sensor (52 x 44.5 mm) shipped with a silicone case. The vendor's own product name for the board is 'HuskyLens K210 AI Vision Sensor': processor Kendryte K210, image sensor OV2640 or GC0328 depending on build, 2.0-inch 320 x 240 IPS screen, and seven built-in algorithms (face recognition, object tracking, object recognition, line tracking, colour recognition, tag recognition, object classification).
ADDRESSES: the wiki publishes no I2C address, so none is recorded and the bus has to be scanned; the address only exists once the device has been switched into I2C mode.
PINOUT: one 4-pin connector whose functions change with the selected mode. UART mode: 1 T = TX, 2 R = RX, 3 - = GND, 4 + = VCC 3.3-5.0 V. I2C mode: 1 T = SDA, 2 R = SCL, 3 - = GND, 4 + = VCC. Numbers 1-4 are the vendor's own table rows. A separate USB connector powers the board and is the firmware-upgrade path.
SUPPLY: 3.3 V to 5.0 V on pad 4. Current 320 mA typical at 3.3 V and 230 mA at 5.0 V, measured in face recognition mode at 80% backlight with the fill light off - the display is what lifts it far above a bare MCU's budget.
LOGIC LEVEL: the UART and I2C pins swing to whatever the board is fed from, so at a 5.0 V feed they are a 5 V bus and are not safe against a 3.3 V-only controller input. Feed it 3.3 V when the host is 3.3 V.
ABSOLUTE MAXIMUMS: the vendor states none, so none are quoted.
REFERENCE CIRCUIT: the vendor publishes no schematic and no pull-up or decoupling values on the product page or the wiki; an I2C host must therefore bring its own pull-ups.
TRAPS: (1) The board prints T and R in both modes - T is TX in UART mode and SDA in I2C mode, R is RX or SCL - so wiring by the printed letter without knowing the selected mode puts the signal on the wrong line. (2) The mode is selected on the device, not by the wiring. (3) The two on-board buttons are the function button and the learning button, and they are the whole user interface. (4) The board carries its own display, so it is meant to run standalone at the point of capture.