pimoroni RP2350 Pico 2 W

AI context

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

PART: Raspberry Pi Pico 2 W, order code SC1633, the same 51 x 21 x 1 mm single-sided 40-pin board as the Pico 2 built on the RP2350A (QFN-60): dual Arm Cortex-M33 or RISC-V Hazard3 cores at up to 150 MHz, 520 kB multi-bank SRAM, 4 MB QSPI flash claimed in the feature list, micro-USB B, a BOOTSEL button and a 3-pin Arm SWD port. What it adds is an on-board 2.4 GHz single-band wireless interface on an Infineon CYW43439 - 802.11n and Bluetooth 5.2, with Bluetooth LE Central and Peripheral roles and Bluetooth Classic support - connected to the RP2350 over SPI, with an on-board antenna licensed from Abracon (formerly ProAnt). Peripherals: 2 x UART, 2 x I2C, 2 x SPI, 16 PWM channels, 1 x HSTX peripheral, 3 PIO blocks with 12 state machines, a 12-bit 500 ksps ADC and USB 1.1 device or host.
FLASH DISAGREEMENT: the feature list on page 3 says 4 MB of flash and the parts list names a Winbond W25Q16JV, which is 2 MB, and the flash section says 'the on-board 2 MB QSPI flash'. Both figures are recorded and neither is resolved here; the part number and the flash section agree on 2 MB.
ADDRESSES: none. There is no I2C device on the board; the CYW43439 is reached over SPI by the vendor's wireless stack, not by address, so nothing answers a bus scan.
PINOUT: 40 pads numbered as Raspberry Pi prints them, 1-20 down the left edge and 40-21 down the right, so pad 1 (GP0) and pad 40 (VBUS) are at the same end: 1 GP0, 2 GP1, 3 GND, 4 GP2, 5 GP3, 6 GP4, 7 GP5, 8 GND, 9 GP6, 10 GP7, 11 GP8, 12 GP9, 13 GND, 14 GP10, 15 GP11, 16 GP12, 17 GP13, 18 GND, 19 GP14, 20 GP15, 21 GP16, 22 GP17, 23 GND, 24 GP18, 25 GP19, 26 GP20, 27 GP21, 28 GND, 29 GP22, 30 RUN, 31 GP26 (ADC0), 32 GP27 (ADC1), 33 AGND, 34 GP28 (ADC2), 35 ADC_VREF, 36 3V3(OUT), 37 3V3_EN, 38 GND, 39 VSYS, 40 VBUS. That is 26 GPIO, 7 ground pads plus AGND, and the six other power and reset pins Raspberry Pi lists as the 40-pin interface. The 40-pin header is identical to the Pico 2's; GPIO0-GP22 are digital only and GPIO26, GPIO27 and GPIO28 double as ADC0, ADC1 and ADC2.
SUPPLY: VBUS is 5 V from micro-USB, fed through a Schottky diode to VSYS; VSYS accepts 1.8 V to 5.5 V into the RT6150 buck-boost SMPS, which holds 3.3 V, so a single lithium-ion cell or 3 x AA cells will run it. 3V3(OUT) may power external circuitry with the vendor's recommendation to keep the load under 300 mA. 3V3_EN is pulled up to VSYS by 100 kOhm and shorting it to ground disables the rail.
LOGIC LEVEL: fixed at 3.3 V - the datasheet states in a note that Pico 2 W I/O voltage is fixed at 3.3 V, while the RP2350 itself is rated 1.8-3.3 V. GPIO26-29 have an internal reverse diode to IOVDD, so their input must not exceed IOVDD plus about 300 mV and driving them while the RP2350 is unpowered leaks into the 3.3 V rail; GPIO0-25 and the debug pins carry no such restriction and tolerate up to 3.3 V while the chip is unpowered.
REFERENCE CIRCUIT: USB 27 Ohm series resistors are fitted, ADC_AVDD is the 3.3 V rail filtered by 201 Ohm into 2.2 uF, the SMPS enable has its 100 kOhm pull-up to VSYS, and VSYS is divided by 3 for the ADC. The wireless section consumes four RP2350 I/O (GPIO23, GPIO24, GPIO25 and GPIO29) plus three CYW43439-side signals, so they are off the header. No SDA/SCL pull-ups are fitted and the datasheet states no values for them; the user adds them.
TRAPS: (1) the user LED, the VBUS sense, the SMPS power-save control and the VSYS/3 divider are NOT on RP2350 GPIOs on this board - they moved to the wireless chip's own pins: WL_GPIO0 is the LED, WL_GPIO1 the SMPS PS control, WL_GPIO2 the VBUS sense, and GPIO29 is the ADC3 input that measures VSYS/3 with GPIO25 as its enable. Code ported from a Pico 2 that toggles GPIO25 or reads GPIO24 for VBUS will not behave the same here. (2) GPIO23, GPIO24, GPIO25 and GPIO29 are consumed by the wireless SPI link, so do not repurpose them. (3) USB host mode needs 5 V on the VBUS pad. (4) AGND (pad 33) is separate from the digital grounds and is the analogue return for GPIO26-29. (5) the ADC has no internal reference, so it measures against the 3.3 V SMPS output. (6) TP4 (WL_GPIO1/SMPS PS) is marked do not use and TP5 (WL_GPIO0/LED) is not recommended for external use because it only swings to the LED forward voltage. (7) the wireless interface shares the board with the flash, so the flash capacity discrepancy above matters when sizing an image.