pimoroni RP2350B Pico Plus 2 W

AI context

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

PART: Pimoroni Pico Plus 2 W, order code PIM726, a 51 x 21 mm (about 53 x 21 x 9 mm with connectors) Raspberry Pi Pico-shaped board on the RP2350B: dual Arm Cortex-M33 at up to 150 MHz, 520 kB SRAM, 48 usable GPIO, 8 ADC channels, 24 PWM channels, and an optional RISC-V Hazard3 pair in place of the M33s. Pimoroni fits 16 MB of QSPI flash (Winbond W25Q128JVPIQ, XiP capable), 8 MB of PSRAM (APS6404L-3SQR-ZR, chip select may be GP0, GP8, GP19 or GP47), a Raspberry Pi RM2 module for 2.4 GHz wireless and Bluetooth, a 3.3 V regulator rated 600 mA, USB-C, a Qw/ST (Qwiic/STEMMA QT) I2C socket, a 3-pin JST-SH debug socket, and reset and BOOT buttons. Pimoroni states the current batch uses RP2350 stepping A4, and that the board keeps the original Pico footprint so existing Pico add-ons fit.
ADDRESSES: none. There is no I2C device on the board; the only I2C traffic is what is plugged into the Qw/ST socket.
PINOUT: 40 pads on 2.54 mm headers, printed GPIO numbers only. Numbering here is the Raspberry Pi Pico convention: 1-20 down the left edge from the USB-C end, 40-21 down the right edge, so pad 1 (GP0) and pad 40 (VBUS) are at the same end: 1=0, 2=1, 3=GND, 4=2, 5=3, 6=4, 7=5, 8=GND, 9=6, 10=7, 11=8, 12=9, 13=GND, 14=10, 15=11, 16=12, 17=13, 18=GND, 19=14, 20=15, 21=16, 22=17, 23=GND, 24=18, 25=19, 26=20, 27=21, 28=GND, 29=22, 30=RUN, 31=26/A0, 32=27/A1, 33=GND, 34=28/A2, 35=ADC_VREF, 36=3V3, 37=3V3 EN, 38=GND, 39=VSYS, 40=VBUS - 26 GPIO, eight grounds, six power and reset pads. Not on the header: GP23 is the wireless module's WL_ON, GP24 is WL_D, GP25 is WL_CS and GP29 is WL_CLK; the user LED hangs off the module's own WL_GPIO0, and the BOOT/user button is GP45, active low. VBUS is sensed on the wireless module too, so an application that wants to know whether USB is present cannot read it from a main-bank GPIO. The Qw/ST socket is I2C0 with SDA on GP4 and SCL on GP5.
SUPPLY: USB-C input rated 3 V to 5.5 V, and the 3.3 V regulator is rated 600 mA maximum output. There is no battery connector and no charging circuit on this board - it is USB-powered only.
LOGIC LEVEL: 3.3 V throughout, and the RP2350B I/O is not 5 V tolerant; a 5 V source on any GPIO needs level shifting.
ANALOGUE: the analogue pads print 26/A0, 27/A1 and 28/A2, but the ADC channels are ADC0, ADC1 and ADC2 on the RP2350B's GPIO40, GPIO41 and GPIO42, each reached through a 1 kOhm element of the RN2 resistor array - the poster annotates the same series resistance as 'internal 1 kOhm'. Treat 1 kOhm as the source impedance of every analogue reading. Pads 26/A0, 27/A1 and 28/A2 are simultaneously ordinary digital GPIO26, GPIO27 and GPIO28 straight off the header.
REFERENCE CIRCUIT: Pimoroni publishes the full schematic (linked in sources), and it shows the USB-C connector with its CC resistors, the 3.3 V regulator with VIN/VOUT/CTRL and a 3V3_EN enable net, the QSPI flash and PSRAM on the RP2350B's QSPI bus, the RN2 1 kOhm array in series with the three ADC pins, and the RM2 module on WL_ON/WL_D/WL_CS/WL_CLK with its own supply pins. No pull-up resistors appear on the Qw/ST SDA and SCL nets, so an I2C add-on has to supply its own. Headers are not fitted and the board ships without them.
TRAPS: (1) GP23, GP24, GP25 and GP29 are taken by the wireless module link and are not on the header - code that assumes GP25 is the LED (as on a plain Pico) is wrong here, because the LED is on WL_GPIO0 inside the module and only the RM2/cyw43 driver can toggle it. (2) PSRAM chip select shares a GPIO with the header in some build options, so check PSRAM_CS before claiming GP0, GP8, GP19 or GP47. (3) The board is USB-powered: there is no LiPo charger, and VSYS on pad 39 is an input rail, not a battery node. (4) The 3.3 V regulator's 600 mA is the whole budget for the module, the PSRAM, the flash and everything on the 3V3 pad.