Waveshare Core2350B

Overview

The Waveshare Core2350B is a compact core board based on the Raspberry Pi RP2350B microcontroller. It brings out 48 GPIOs on 2.54 mm pitch headers for integration into carrier boards. USB is provided through a 6-pin FPC connector, which connects to a USB Type-C port through an optional adapter board.

The board is available in three variants that differ only in the populated PSRAM:

Core2350B0: no PSRAM
Core2350B1: 2 MB PSRAM
Core2350B2: 8 MB PSRAM

The RP2350B SoC has two Cortex-M33 cores and two Hazard3 (RISC-V) cores. Zephyr supports builds targeting either CPU architecture, but currently runs on one core only; running code on the second core is not supported.

Hardware

RP2350B microcontroller with dual Cortex-M33 or dual Hazard3 processors at up to 150 MHz
520 KB of SRAM and 16 MB of QSPI flash (W25Q128JVSIQ)
Optional 2 MB or 8 MB QSPI PSRAM, depending on the variant
12 MHz crystal oscillator
6-pin 0.5 mm pitch FPC connector carrying VBUS, USB D+/D-, BOOTSEL and RUN
ME6217C33M5G 3.3 V LDO regulator (800 mA), enable signal available on the header
64 pins on four 2x8 headers with 2.54 mm pitch
USB 1.1 with device and host support
Low-power sleep and dormant modes
Drag-and-drop programming using mass storage over USB
48 multi-function GPIO pins, 8 of which can be used as ADC inputs
2 SPI, 2 I2C, 2 UART, 8 12-bit ADC channels, 24 controllable PWM channels
Temperature sensor
3 Programmable I/O (PIO) blocks, 12 state machines total
SWD debug port on the header
User LED (red) on GPIO39

Supported Features

The core2350b board supports the hardware features listed below.

on-chip / on-board: Feature integrated in the SoC / present on the board.
2 / 2: Number of instances that are enabled / disabled.
Click on the label to see the first instance of this feature in the board/SoC DTS files.
vnd,foo: Compatible string for the Devicetree binding matching the feature.
Click on the link to view the binding documentation.

`core2350b/rp2350b/hazard3_0` target

On-target memory for this board target: 520 KiB of RAM, 16 MiB of Flash.

Type	Location	Description	Compatible
CPU	on-chip	Generic RISC-V CPU2	`riscv`
ADC	on-chip	Raspberry Pi Pico ADC1	`raspberrypi,pico-adc`
Clock control	on-chip	The representation of Raspberry Pi Pico’s clock11 2	`raspberrypi,pico-clock`
	on-chip	The representation of Raspberry Pi Pico’s PLL2	`raspberrypi,pico-pll`
	on-chip	The representation of Raspberry Pi Pico ring oscillator1	`raspberrypi,pico-rosc`
	on-chip	The representation of Raspberry Pi Pico external oscillator1	`raspberrypi,pico-xosc`
	on-chip	Raspberry Pi Pico clock controller node1	`raspberrypi,pico-clock-controller`
Counter	on-chip	Raspberry Pi Pico timer1 1	`raspberrypi,pico-timer`
Cryptographic accelerator	on-chip	Raspberry Pi Pico SHA-256 accelerator1	`raspberrypi,pico-sha256`
DMA	on-chip	Raspberry Pi Pico DMA1	`raspberrypi,pico-dma`
Flash controller	on-chip	Raspberry Pi Pico flash controller1	`raspberrypi,pico-flash-controller`
GPIO & Headers	on-chip	Raspberry Pi Pico GPIO1	`raspberrypi,pico-gpio`
GPIO & Headers	on-chip	Raspberry Pi Pico GPIO Port2	`raspberrypi,pico-gpio-port`
I2C	on-chip	Raspberry Pi Pico I2C2	`raspberrypi,pico-i2c`
Interrupt controller	on-chip	Hazard3 interrupt controller1	`hazard3,hazard3-intc`
LED	on-board	Group of GPIO-controlled LEDs1	`gpio-leds`
LED	on-board	Group of PWM-controlled LEDs1	`pwm-leds`
Mailbox	on-chip	Raspberry Pi Pico interprocessor mailbox1	`raspberrypi,pico-mbox`
Miscellaneous	on-chip	Raspberry Pi Pico POWMAN (power manager)1	`raspberrypi,pico-powman`
	on-chip	Raspberry Pi Pico PIO3	`raspberrypi,pico-pio`
	on-chip	Raspberry Pi Pico SIO1	`raspberrypi,pico-sio`
MTD	on-chip	Flash node1	`soc-nv-flash`
Pin control	on-chip	Raspberry Pi Pico Pin Controller1	`raspberrypi,pico-pinctrl`
PWM	on-chip	Raspberry Pi Pico PWM1	`raspberrypi,pico-pwm`
Regulator	on-chip	Raspberry Pi Pico core supply regurator1	`raspberrypi,core-supply-regulator`
Reset controller	on-chip	Raspberry Pi Pico Reset Controller1	`raspberrypi,pico-reset`
RNG	on-chip	Raspberry Pi Pico RNG/Entropy1	`raspberrypi,pico-rng`
Sensors	on-chip	Raspberry Pi Pico family temperature sensor node1	`raspberrypi,pico-temp`
Serial controller	on-chip	Raspberry Pi Pico UART1 1	`raspberrypi,pico-uart`
SPI	on-chip	Raspberry Pi Pico SPI1 1	`raspberrypi,pico-spi`
SRAM	on-chip	Generic on-chip SRAM1	`mmio-sram`
Timer	on-chip	RISC-V Machine Timer1	`riscv,machine-timer`
USB	on-chip	Raspberry Pi Pico USB Device Controller1	`raspberrypi,pico-usbd`
Watchdog	on-chip	Raspberry Pi Pico Watchdog1	`raspberrypi,pico-watchdog`

`core2350b/rp2350b/m33_0` target

On-target memory for this board target: 520 KiB of RAM, 16 MiB of Flash.

Type	Location	Description	Compatible
CPU	on-chip	ARM Cortex-M33 CPU2	`arm,cortex-m33`
ADC	on-chip	Raspberry Pi Pico ADC1	`raspberrypi,pico-adc`
Clock control	on-chip	The representation of Raspberry Pi Pico’s clock11 2	`raspberrypi,pico-clock`
	on-chip	The representation of Raspberry Pi Pico’s PLL2	`raspberrypi,pico-pll`
	on-chip	The representation of Raspberry Pi Pico ring oscillator1	`raspberrypi,pico-rosc`
	on-chip	The representation of Raspberry Pi Pico external oscillator1	`raspberrypi,pico-xosc`
	on-chip	Raspberry Pi Pico clock controller node1	`raspberrypi,pico-clock-controller`
Counter	on-chip	Raspberry Pi Pico timer1 1	`raspberrypi,pico-timer`
Cryptographic accelerator	on-chip	Raspberry Pi Pico SHA-256 accelerator1	`raspberrypi,pico-sha256`
DMA	on-chip	Raspberry Pi Pico DMA1	`raspberrypi,pico-dma`
Flash controller	on-chip	Raspberry Pi Pico flash controller1	`raspberrypi,pico-flash-controller`
GPIO & Headers	on-chip	Raspberry Pi Pico GPIO1	`raspberrypi,pico-gpio`
GPIO & Headers	on-chip	Raspberry Pi Pico GPIO Port2	`raspberrypi,pico-gpio-port`
I2C	on-chip	Raspberry Pi Pico I2C2	`raspberrypi,pico-i2c`
Interrupt controller	on-chip	ARMv8-M NVIC (Nested Vectored Interrupt Controller)1	`arm,v8m-nvic`
LED	on-board	Group of GPIO-controlled LEDs1	`gpio-leds`
LED	on-board	Group of PWM-controlled LEDs1	`pwm-leds`
Mailbox	on-chip	Raspberry Pi Pico interprocessor mailbox1	`raspberrypi,pico-mbox`
Miscellaneous	on-chip	Raspberry Pi Pico POWMAN (power manager)1	`raspberrypi,pico-powman`
	on-chip	Raspberry Pi Pico PIO3	`raspberrypi,pico-pio`
	on-chip	Raspberry Pi Pico SIO1	`raspberrypi,pico-sio`
MTD	on-chip	Flash node1	`soc-nv-flash`
Pin control	on-chip	Raspberry Pi Pico Pin Controller1	`raspberrypi,pico-pinctrl`
PWM	on-chip	Raspberry Pi Pico PWM1	`raspberrypi,pico-pwm`
Regulator	on-chip	Raspberry Pi Pico core supply regurator1	`raspberrypi,core-supply-regulator`
Reset controller	on-chip	Raspberry Pi Pico Reset Controller1	`raspberrypi,pico-reset`
RNG	on-chip	Raspberry Pi Pico RNG/Entropy1	`raspberrypi,pico-rng`
Sensors	on-chip	Raspberry Pi Pico family temperature sensor node1	`raspberrypi,pico-temp`
Serial controller	on-chip	Raspberry Pi Pico UART1 1	`raspberrypi,pico-uart`
SPI	on-chip	Raspberry Pi Pico SPI1 1	`raspberrypi,pico-spi`
SRAM	on-chip	Generic on-chip SRAM1	`mmio-sram`
Timer	on-chip	ARMv8-M System Tick1	`arm,armv8m-systick`
USB	on-chip	Raspberry Pi Pico USB Device Controller1	`raspberrypi,pico-usbd`
Watchdog	on-chip	Raspberry Pi Pico Watchdog1	`raspberrypi,pico-watchdog`

Connections and IOs

The board has no buttons and no USB connector of its own. The BOOTSEL and RUN signals, the USB data lines and VBUS are routed both to the FPC connector and to header P2. The USB Type-C adapter board connected through the FPC cable provides the BOOT and RESET buttons.

Headers

P1: GPIO0 to GPIO14
P3: GPIO15 to GPIO29
P4: GPIO30 to GPIO44
P2: GPIO45 to GPIO47, SWCLK, SWD, BOOTSEL, RUN, USBD_P, USBD_N, ADC_VREF, 3V3_EN, VBUS and 3V3

The board is powered from VBUS (5 V) through the FPC connector or header P2. Pulling 3V3_EN low disables the 3.3 V regulator.

Default Zephyr Peripheral Mapping

UART0_TX : GPIO0
UART0_RX : GPIO1
I2C0_SDA : GPIO4
I2C0_SCL : GPIO5
I2C1_SDA : GPIO6
I2C1_SCL : GPIO7
SPI0_RX : GPIO16
SPI0_CSN : GPIO17
SPI0_SCK : GPIO18
SPI0_TX : GPIO19
LED0 / PWM_11B : GPIO39
ADC_CH0 : GPIO40
ADC_CH1 : GPIO41
ADC_CH2 : GPIO42
ADC_CH3 : GPIO43
ADC_CH4 : GPIO44
ADC_CH5 : GPIO45
ADC_CH6 : GPIO46

The Zephyr console and shell use USB CDC ACM by default.

GPIO47 (ADC channel 7) is the PSRAM chip select and also reaches header P2 through a 0 ohm resistor (R11). On the Core2350B1 and Core2350B2 variants, do not use it as a general-purpose pin. PSRAM is not currently supported in Zephyr.

Programming and Debugging

The core2350b board supports the runners and associated west commands listed below.

	flash	debug	attach	debugserver	rtt	reset
jlink	✅	✅	✅	✅	✅	✅
openocd	✅ (default)	✅ (default)	✅	✅	✅
probe-rs	✅	✅		✅	✅
uf2	✅

The overall explanation regarding flashing and debugging is the same as for Raspberry Pi Pico. See Programming and Debugging in Raspberry Pi Pico documentation. N.b. OpenOCD support requires using Raspberry Pi’s forked version of OpenOCD. The SWD signals are available on header P2.

Flashing with UF2

To enter the UF2 bootloader with the USB Type-C adapter board connected, hold the BOOT button, press and release RESET, then release BOOT. Without the adapter board, pull BOOTSEL to ground while pulsing RUN low on header P2. The board then appears on the host as a mass storage device.

Below is an example of building and flashing the Blinky application.

# From the root of the zephyr repository
west build -b core2350b/rp2350b/m33_0 samples/basic/blinky
west flash -r uf2

To target the Hazard3 (RISC-V) core instead, use core2350b/rp2350b/hazard3_0 as the board.