pico-arduino-compat

A compatibility layer that allows the use of Arduino libraries with the Pico C/C++ SDK.

Installation

Clone pico-arduino-compat into somewhere convenient. Here we'll use /home/fhdm-dev/pico

cd /home/fhdm-dev/pico
git clone https://github.com/fhdm-dev/pico-arduino-compat.git

Get the arduino-pico submodule

cd pico-arduino-compat
git submodule update --init arduino-compat/arduino-pico

How to include an Arduino library into an existing project

Get the submodule for the library and dependent libraries eg. if we're including the adafruit-ssd1306 library

cd libs/adafruit-ssd1306
./init.sh

In your project's CMakeLists.txt file, add the library directory as a subdirectory.

eg.

add_subdirectory(/home/fhdm-dev/pico/pico-arduino-compat/libs/adafruit-ssd1306)

eg.

target_link_libraries(boom
  pico_stdlib
  adafruit-ssd1306
)

Arduino Global Variables

The table below shows how the Arduino global variables such as SPI, Wire, Serial etc map to Pico peripheral instances and GPIOs

Arduino Global Variable	Pico Peripheral Instance	GPIOs
SPI	spi0	16,17,18,19
SPI1	spi1	12,13,14,15
Wire	i2c0	4,5
Wire1	i2c1	10,11
Serial	Uses stdio	USB or 0,1
Serial1	uart0	0,1
Serial2	uart1	8,9

Compatibility

Arduino libraries that use direct register access or interrupts will not work.

Directory structure

The directory structure of this repository is as follows:
arduino-compat: The compatibility layer
libs: The Arduino libraries and associated CMakeLists.txt files and examples
official-libs: Selected libraries from the official Arduino libraries repository
pico-libs: The C/C++ wrappers for the Arduino libraries

FAQ

How is pico-arduino-compat different from the Arduino RP2040 mbed core or the Arduino-Pico core?

These cores allow you to use the Arduino IDE to program the Pico/RP2040. pico-arduino-compat is for using Arduino libraries with the Pico C/C++ SDK.

Can Arduino sketches be used with pico-arduino-compat?

If the sketch uses functions and libraries implemented by pico-arduino-compat then it should run with a little modification. Most of the examples under arduino-libs are just modified Arduino sketches.

Do applications using pico-arduino-compat run slower or use more resources?

Probably!

Do Arduino Libraries need to be modified to work with pico-arduino-compat?

Some don't. Some probably do. Some probably wont work at all.

Acknowledgments

Much of the code uses earlephilhower's Pi Pico Arduino core.