Pico-SPE

Overview

The Pico-SPE is a small, low-cost, versatile boards from KWS Computersysteme Gmbh. They are equipped with an RP2040 SoC, an on-board LED, a USB connector, an SWD interface. The Pico-SPE additionally contains an Microchip LAN8651 10Base-T1S module. The USB bootloader allows the ability to flash without any adapter, in a drag-and-drop manner. It is also possible to flash and debug the boards with their SWD interface, using an external adapter.

Hardware

  • Dual core Arm Cortex-M0+ processor running up to 133MHz

  • 264KB on-chip SRAM

  • 16MB on-board QSPI flash with XIP capabilities

  • 16 GPIO pins

  • 3 Analog inputs

  • 2 UART peripherals

  • 2 I2C controllers

  • 16 PWM channels

  • USB 1.1 controller (host/device)

  • 8 Programmable I/O (PIO) for custom peripherals

  • On-board LED

  • 1 Watchdog timer peripheral

  • Microchip LAN8651 10Base-T1S

Supported Features

The pico_spe 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.
pico_spe
/
rp2040

Type

Location

Description

Compatible

CPU

on-chip

ARM Cortex-M0+ CPU2

arm,cortex-m0+

ADC

on-chip

Raspberry Pi Pico ADC1

raspberrypi,pico-adc

Clock control

on-chip

Raspberry Pi Pico clock controller node1

raspberrypi,pico-clock-controller

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

Counter

on-chip

Raspberry Pi Pico timer1

raspberrypi,pico-timer

DMA

on-chip

Raspberry Pi Pico DMA1

raspberrypi,pico-dma

Ethernet

on-board

LAN865x standalone 10BASE-T1L Ethernet controller with SPI interface1

microchip,lan865x

on-board

Microchip’s 10BASE-T1S PHYs support1

microchip,t1s-phy

Flash controller

on-chip

Raspberry Pi Pico flash controller1

raspberrypi,pico-flash-controller

GPIO & Headers

on-chip

Raspberry Pi Pico GPIO1

raspberrypi,pico-gpio

on-chip

Raspberry Pi Pico GPIO Port1

raspberrypi,pico-gpio-port

on-board

GPIO pins exposed on Raspberry Pi Pico headers1

raspberrypi,pico-header

I2C

on-chip

Raspberry Pi Pico I2C1 1

raspberrypi,pico-i2c

Interrupt controller

on-chip

ARMv6-M NVIC (Nested Vectored Interrupt Controller) controller1

arm,v6m-nvic

LED

on-board

Group of GPIO-controlled LEDs1

gpio-leds

on-board

Group of PWM-controlled LEDs1

pwm-leds

Miscellaneous

on-chip

Raspberry Pi Pico PIO2

raspberrypi,pico-pio

MTD

on-chip

Flash node1

soc-nv-flash

on-board

Fixed partitions of a flash (or other non-volatile storage) memory1

fixed-partitions

Pin control

on-chip

The RPi Pico pin controller is a node responsible for controlling pin function selection and pin properties, such as routing a UART0 Rx to pin 1 and enabling the pullup resistor on that pin1

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

RTC

on-chip

Raspberry Pi Pico RTC1

raspberrypi,pico-rtc

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

ARMv6-M System Tick1

arm,armv6m-systick

USB

on-chip

Raspberry Pi Pico USB Device Controller1

raspberrypi,pico-usbd

Watchdog

on-chip

Raspberry Pi Pico Watchdog1

raspberrypi,pico-watchdog

Pin Mapping

The peripherals of the RP2040 SoC can be routed to various pins on the board. The configuration of these routes can be modified through DTS. Please refer to the datasheet to see the possible routings for each peripheral.

External pin mapping on the Pico-SPE is identical to the Pico, but note that internal RP2040 GPIO lines 10, 11, 12, 13, 20, 21 are routed to the Microchip LAN8651 on the Pico-SPE.

Default Zephyr Peripheral Mapping:

  • UART0_TX : P0

  • UART0_RX : P1

  • I2C0_SDA : P4

  • I2C0_SCL : P5

  • I2C1_SDA : P6

  • I2C1_SCL : P7

  • ADC_CH0 : P26

  • ADC_CH1 : P27

  • ADC_CH2 : P28

Programmable I/O (PIO)

The RP2040 SoC comes with two PIO periherals. These are two simple co-processors that are designed for I/O operations. The PIOs run a custom instruction set, generated from a custom assembly language. PIO programs are assembled using pioasm, a tool provided by Raspberry Pi.

Zephyr does not (currently) assemble PIO programs. Rather, they should be manually assembled and embedded in source code. An example of how this is done can be found at drivers/serial/uart_rpi_pico_pio.c.

Sample: SPI via PIO

The BME280 humidity and pressure sensor sample includes a demonstration of using the PIO SPI driver to communicate with an environmental sensor. The PIO SPI driver supports using any combination of GPIO pins for an SPI bus, as well as allowing up to four independent SPI buses on a single board (using the two SPI devices as well as both PIO devices).

Programming and Debugging

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

flash debug attach debugserver rtt
blackmagicprobe
jlink
openocd ✅ (default) ✅ (default)
pyocd
uf2

Flashing

Using OpenOCD

To use CMSIS-DAP, you must configure udev.

Create a file in /etc/udev.rules.d with any name, and write the line below.

ATTRS{idVendor}=="2e8a", ATTRS{idProduct}=="000c", MODE="660", GROUP="plugdev", TAG+="uaccess"

This example is valid for the case that the user joins to plugdev groups.

The Pico-SPE has an SWD interface that can be used to program and debug the on board RP2040. This interface can be utilized by OpenOCD. To use it with the RP2040, OpenOCD version 0.12.0 or later is needed.

If you are using a Debian based system (including RaspberryPi OS, Ubuntu. and more), using the pico_setup.sh [1] script is a convenient way to set up the forked version of OpenOCD.

Depending on the interface used (such as JLink), you might need to checkout to a branch that supports this interface, before proceeding. Build and install OpenOCD as described in the README.

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

# From the root of the zephyr repository
west build -b pico_spe samples/basic/blinky -- -DOPENOCD=/usr/local/bin/openocd -DOPENOCD_DEFAULT_PATH=/usr/local/share/openocd/scripts -DRPI_PICO_DEBUG_ADAPTER=cmsis-dap
west flash

Set the environment variables OPENOCD to /usr/local/bin/openocd and OPENOCD_DEFAULT_PATH to /usr/local/share/openocd/scripts. This should work with the OpenOCD that was installed with the default configuration. This configuration also works with an environment that is set up by the pico_setup.sh [1] script.

RPI_PICO_DEBUG_ADAPTER specifies what debug adapter is used for debugging.

If RPI_PICO_DEBUG_ADAPTER was not assigned, cmsis-dap is used by default. The other supported adapters are raspberrypi-swd, jlink and blackmagicprobe. How to connect cmsis-dap and raspberrypi-swd is described in Getting Started with Pico-SPE-Series [2]. Any other SWD debug adapter maybe also work with this configuration.

The value of RPI_PICO_DEBUG_ADAPTER is cached, so it can be omitted from west flash and west debug if it was previously set while running west build.

RPI_PICO_DEBUG_ADAPTER is used in an argument to OpenOCD as "source [find interface/${RPI_PICO_DEBUG_ADAPTER}.cfg]". Thus, RPI_PICO_DEBUG_ADAPTER needs to be assigned the file name of the debug adapter.

You can also flash the board with the following command that directly calls OpenOCD (assuming a SEGGER JLink adapter is used):

$ openocd -f interface/jlink.cfg -c 'transport select swd' -f target/rp2040.cfg -c "adapter speed 2000" -c 'targets rp2040.core0' -c 'program path/to/zephyr.elf verify reset exit'

Using UF2

If you don’t have an SWD adapter, you can flash the Pico-SPE with a UF2 file. By default, building an app for this board will generate a build/zephyr/zephyr.uf2 file. If the Pico is powered on with the BOOTSEL button pressed, it will appear on the host as a mass storage device. The UF2 file should be drag-and-dropped to the device, which will flash the Pico.

Debugging

The SWD interface can also be used to debug the board. To achieve this, you can either use SEGGER JLink or OpenOCD.

Using SEGGER JLink

Use a SEGGER JLink debug probe and follow the instruction in Building, Flashing and Debugging.

Using OpenOCD

Install OpenOCD as described for flashing the board.

Here is an example for debugging the Blinky application.

# From the root of the zephyr repository
west build -b pico_spe samples/basic/blinky -- -DOPENOCD=/usr/local/bin/openocd -DOPENOCD_DEFAULT_PATH=/usr/local/share/openocd/scripts -DRPI_PICO_DEBUG_ADAPTER=raspberrypi-swd
west debug

As with flashing, you can specify the debug adapter by specifying RPI_PICO_DEBUG_ADAPTER at west build time. No needs to specify it at west debug time.

You can also debug with OpenOCD and gdb launching from command-line. Run the following command:

$ openocd -f interface/jlink.cfg -c 'transport select swd' -f target/rp2040.cfg -c "adapter speed 2000" -c 'targets rp2040.core0'

On another terminal, run:

$ gdb-multiarch

Inside gdb, run:

(gdb) tar ext :3333
(gdb) file path/to/zephyr.elf

You can then start debugging the board.