Arduino-Pico

Raspberry Pi Pico Arduino core, for all RP2040 boards

This is a port of the RP2040 (Raspberry Pi Pico processor) to the Arduino ecosystem. It uses the bare Raspberry Pi Pico SDK and a custom GCC 12.3/Newlib 4.0 toolchain.

Documentation

See https://arduino-pico.readthedocs.io/en/latest/ along with the examples for more detailed usage information.

Contributing

Read the Contributing Guide for more information on submitting pull requests and porting libraries or sketches to this core.

Supported Boards

Raspberry Pi Pico
Raspberry Pi Pico W
0xCB Helios
Adafruit Feather RP2040
Adafruit Feather RP2040 SCORPIO
Adafruit ItsyBitsy RP2040
Adafruit KB2040
Adafruit Macropad RP2040
Adafruit Metro RP2040
Adafruit QTPy RP2040
Adafruit STEMMA Friend RP2040
Adafruit Trinkey RP2040 QT
Amken Bunny
Amken Revelop
Amken Revelop Plus
Amken Revelop eS
Arduino Nano RP2040 Connect
ArtronShop RP2 Nano
Breadstick Raspberry
BridgeTek IDM2040-7A
BridgeTek IDM2040-43A
Cytron Maker Pi RP2040
Cytron Maker Nano RP2040
Cytron Maker Uno RP2040
DatanoiseTV PicoADK+
Degz Suibo RP2040
DeRuiLab FlyBoard2040 Core
DFRobot Beetle RP2040
ElectronicCats Hunter Cat NFC
EVN Alpha
ExtremeElectronics RC2040
GroundStudio Marble Pico
Invector Labs Challenger RP2040 WiFi
Invector Labs Challenger RP2040 WiFi/BLE
Invector Labs Challenger RP2040 WiFi6/BLE
Invector Labs Challenger NB RP2040 WiFi
Invector Labs Challenger RP2040 LTE
Invector Labs Challenger RP2040 LoRa
Invector Labs Challenger RP2040 SubGHz
Invector Labs Challenger RP2040 SD/RTC
Invector Labs Challenger RP2040 UWB
Invector Labs RPICO32
Melopero Cookie RP2040
Melopero Shake RP2040
METE HOCA Akana R1
Neko Systems BL2040 Mini
Olimex RP2040-Pico30
Newsan Archi
nullbits Bit-C PRO
Pimoroni PGA2040
Pimoroni Plasma2040
Pimoroni Tiny2040
Pintronix PinMax
RAKwireless RAK11300
Redscorp RP2040-Eins
Redscorp RP2040-ProMini
Sea-Picro
Seeed Indicator RP2040
Seeed XIAO RP2040
Silicognition RP2040-Shim
Solder Party RP2040 Stamp
SparkFun MicroMod RP2040
SparkFun ProMicro RP2040
SparkFun Thing Plus RP2040
uPesy RP2040 DevKit
VCC-GND YD-RP2040
Viyalab Mizu RP2040
Waveshare RP2040 Zero
Waveshare RP2040 One
Waveshare RP2040 Plus
Waveshare RP2040 LCD 0.96
Waveshare RP2040 LCD 1.28
Waveshare RP2040 Matrix
Waveshare RP2040 PiZero
WIZnet W5100S-EVB-Pico
WIZnet W5500-EVB-Pico
WIZnet WizFi360-EVB-Pico
Generic (configurable flash, I/O pins)

Features

Adafruit TinyUSB Arduino (USB mouse, keyboard, flash drive, generic HID, CDC Serial, MIDI, WebUSB, others)
Bluetooth on the PicoW (Classic and BLE) with Keyboard, Mouse, Joystick, and Virtual Serial
Bluetooth Classic and BLE HID master mode (connect to BT keyboard, mouse, or joystick)
Generic Arduino USB Serial, Keyboard, Joystick, and Mouse emulation
WiFi (Pico W, ESP32-based ESPHost, Atmel WINC1500)
Ethernet (Wired W5500, W5100, ENC28J60)
HTTP client and server (WebServer)
SSL/TLS/HTTPS
Over-the-Air (OTA) upgrades
Filesystems (LittleFS and SD/SDFS)
Multicore support (setup1() and loop1())
FreeRTOS SMP support
Overclocking and underclocking from the menus
digitalWrite/Read, shiftIn/Out, tone, analogWrite(PWM)/Read, temperature
Analog stereo audio in using DMA and the built-in ADC
Analog stereo audio out using PWM hardware
Bluetooth A2DP audio source (output) and sink (input) on the PicoW
USB drive mode for data loggers (SingleFileDrive, FatFSUSB)
Peripherals: SPI master/slave, Wire(I2C) master/slave, dual UART, emulated EEPROM, I2S audio input/output, Servo
printf (i.e. debug) output over USB serial

The RP2040 PIO state machines (SMs) are used to generate jitter-free:

Servos
Tones
I2S Input
I2S Output
Software UARTs (Serial ports)

Installing via Arduino Boards Manager

Windows-specific Notes

Please do not use the Windows Store version of the actual Arduino application because it has issues detecting attached Pico boards. Use the "Windows ZIP" or plain "Windows" executable (EXE) download direct from https://arduino.cc. and allow it to install any device drivers it suggests. Otherwise the Pico board may not be detected. Also, if trying out the 2.0 beta Arduino please install the release 1.8 version beforehand to ensure needed device drivers are present. (See #20 for more details.)

Linux-specific Notes

Installing Arduino using flatpak (often used by "App Stores" in various Linux distributions) will mean it has restricted access to the host. This might cause uploads to fail with error messages such as the following:

Scanning for RP2040 devices
...
No drive to deploy.

If you encounter this, you will need to either install Arduino in a different manner, or override the flatpak sandboxing feature using the following command, then restarting Arduino.

flatpak override --user --filesystem=host:ro cc.arduino.IDE2

Installation

Open up the Arduino IDE and go to File->Preferences.

In the dialog that pops up, enter the following URL in the "Additional Boards Manager URLs" field:

https://github.com/earlephilhower/arduino-pico/releases/download/global/package_rp2040_index.json

Hit OK to close the dialog.

Go to Tools->Boards->Board Manager in the IDE

Type "pico" in the search box and select "Add":

Installing via GIT

Windows Users: Before installing via git on Windows, please read and follow the directions in this link. If Win32 long paths are not enabled, and git not configured to use them then there may be errors when attempting to clone the submodules.

To install via GIT (for latest and greatest versions):

mkdir -p ~/Arduino/hardware/pico
git clone https://github.com/earlephilhower/arduino-pico.git ~/Arduino/hardware/pico/rp2040
cd ~/Arduino/hardware/pico/rp2040
git submodule update --init
cd pico-sdk
git submodule update --init
cd ../tools
python3 ./get.py

Installing both Arduino and CMake

Tom's Hardware presented a very nice writeup on installing arduino-pico on both Windows and Linux, available at https://www.tomshardware.com/how-to/program-raspberry-pi-pico-with-arduino-ide

If you follow Les' step-by-step you will also have a fully functional CMake-based environment to build Pico apps on if you outgrow the Arduino ecosystem.

Uploading Sketches

To upload your first sketch, you will need to hold the BOOTSEL button down while plugging in the Pico to your computer. Then hit the upload button and the sketch should be transferred and start to run.

After the first upload, this should not be necessary as the arduino-pico core has auto-reset support. Select the appropriate serial port shown in the Arduino Tools->Port->Serial Port menu once (this setting will stick and does not need to be touched for multiple uploads). This selection allows the auto-reset tool to identify the proper device to reset. Them hit the upload button and your sketch should upload and run.

In some cases the Pico will encounter a hard hang and its USB port will not respond to the auto-reset request. Should this happen, just follow the initial procedure of holding the BOOTSEL button down while plugging in the Pico to enter the ROM bootloader.

Uploading Filesystem Images

The onboard flash filesystem for the Pico, LittleFS, lets you upload a filesystem image from the sketch directory for your sketch to use. Download the needed plugin from

https://github.com/earlephilhower/arduino-pico-littlefs-plugin/releases

To install, follow the directions in

https://github.com/earlephilhower/arduino-pico-littlefs-plugin/blob/master/README.md

For detailed usage information, please check the ESP8266 repo documentation (ignore SPIFFS related notes) available at

https://arduino-esp8266.readthedocs.io/en/latest/filesystem.html

Uploading Sketches with Picoprobe

If you have built a Raspberry Pi Picoprobe, you can use OpenOCD to handle your sketch uploads and for debugging with GDB.

Under Windows a local admin user should be able to access the Picoprobe port automatically, but under Linux udev must be told about the device and to allow normal users access.

To set up user-level access to Picoprobes on Ubuntu (and other OSes which use udev):

echo 'SUBSYSTEMS=="usb", ATTRS{idVendor}=="2e8a", ATTRS{idProduct}=="0004", MODE="0666"' | sudo tee -a /etc/udev/rules.d/98-PicoProbe.rules
sudo udevadm control --reload
sudo udevadm trigger -w -s usb

The first line creates a device file in /dev matching the USB vendor and product ID of the Picoprobe, and it enables global read+write permissions. The second line causes udev to load this new rule. The third line requests the kernel generate "device change" events that will cause our new udev rule to run.

If for some reason the device file does not appear, manually unplug and re-plug the USB connection and check again. The output from dmesg can reveal useful diagnostics if the device file remains absent.

Once Picoprobe permissions are set up properly, then select the board "Raspberry Pi Pico (Picoprobe)" in the Tools menu and upload as normal.

Uploading Sketches with pico-debug

pico-debug differs from Picoprobe in that pico-debug is a virtual debug pod that runs side-by-side on the same RP2040 that you run your code on; so, you only need one RP2040 board instead of two. pico-debug also differs from Picoprobe in that pico-debug is standards-based; it uses the CMSIS-DAP protocol, which means even software not specially written for the Raspberry Pi Pico can support it. pico-debug uses OpenOCD to handle your sketch uploads, and debugging can be accomplished with CMSIS-DAP capable debuggers including GDB.

Under Windows and macOS, any user should be able to access pico-debug automatically, but under Linux udev must be told about the device and to allow normal users access.

To set up group-level access to all CMSIS-DAP adapters on Ubuntu (and other OSes which use udev):

echo 'ATTRS{product}=="*CMSIS-DAP*", MODE="664", GROUP="plugdev"' | sudo tee -a /etc/udev/rules.d/98-CMSIS-DAP.rules
sudo udevadm control --reload
sudo udevadm trigger -w -s usb

The first line creates a device file in /dev that matches all CMSIS-DAP adapters, and it enables read+write permissions for members of the plugdev group. The second line causes udev to load this new rule. The third line requests the kernel generate "device change" events that will cause our new udev rule to run.

Once CMSIS-DAP permissions are set up properly, then select the board "Raspberry Pi Pico (pico-debug)" in the Tools menu.

When first connecting the USB port to your PC, you must copy pico-debug-gimmecache.uf2 to the Pi Pico to load pico-debug into RAM; after this, upload as normal.

Debugging with Picoprobe/pico-debug, OpenOCD, and GDB

The installed tools include a version of OpenOCD (in the pqt-openocd directory) and GDB (in the pqt-gcc directory). These may be used to run GDB in an interactive window as documented in the Pico Getting Started manuals from the Raspberry Pi Foundation. For pico-debug, replace the raspberrypi-swd and picoprobe example OpenOCD arguments of "-f interface/raspberrypi-swd.cfg -f target/rp2040.cfg" or "-f interface/picoprobe.cfg -f target/rp2040.cfg" respectively in the Pico Getting Started manual with "-f board/pico-debug.cfg".

Licensing and Credits

The Arduino IDE and ArduinoCore-API are developed and maintained by the Arduino team. The IDE is licensed under GPL.
The RP2040 GCC-based toolchain is licensed under under the GPL.
The Pico-SDK is by Raspberry Pi (Trading) Ltd and licensed under the BSD 3-Clause license.
Arduino-Pico core files are licensed under the LGPL.
LittleFS library written by ARM Limited and released under the BSD 3-clause license.
UF2CONV.PY is by Microsoft Corporation and licensed under the MIT license.
Networking and filesystem code taken from the ESP8266 Arduino Core and licensed under the LGPL.
DHCP server for AP host mode from the Micropython Project, distributed under the MIT License.
FreeRTOS is copyright Amazon.com, Inc. or its affiliates, and distributed under the MIT license.
lwIP is (c) the Swedish Institute of Computer Science and licenced under the BSD license.
BearSSL library written by Thomas Pornin, is distributed under the MIT License.
UZLib is copyright (c) 2003 Joergen Ibsen and distributed under the zlib license.
LEAmDNS is copyright multiple authors and distributed under the MIT license.
http-parser is copyright Joyent, Inc. and other Node contributors.
WebServer code modified from the ESP32 WebServer and is copyright (c) 2015 Ivan Grokhotkov and others.
Xoshiro-cpp is copyright (c) 2020 Ryo Suzuki and distributed under the MIT license.

-Earle F. Philhower, III
earlephilhower@yahoo.com

red-scorp/arduino-pico