user60304: I recently bought a Raspberry Pi Pico to play with, and am attempting to upload my first program to it the Arduino way, as my own operating system rather than a c++ program over an existing operating system (meaning to replace the built-in Raspberry Pi Pico operating system which runs MicroPython, not in the sense of running Linux, Windows, Mac, or any derivative or fork). I have not found any record of people hacking it like that - is it possible? If so, how would I go about it? Sorry if this is in the wrong Stack Exchange.

user71205: Here is the library for the Arduino IDE and a Raspberry Pi pico.
https://github.com/lrusak/Arduino-Core-Pico
Just install normally as a .zip.

user63711: It is worth mentioning this excellent alternative to the Arduino one from Earle F. Philhower. It seems well-maintained and doesn't depend on Mbed OS, so it leaves more space (ram and flash) for your application.
Here an informal comparative list.

user70020: Official support.
Apparently there's official support for it, now anyway.
I was digging around in the Arduino-mbed core, trying to help someone else, specifically in the boards.txt and spied the line:

pico.name=Raspberry Pi Pico

Unfortunately, I don't have any way to give it a proper test as I don't have one of these.  But I did go so far as to install the core and compile a simple hello world program.
In boards manager
Search for "mbed rp2040"; these names sometimes change, but those terms work well now.  You can see in the lower item, I have version 2.0.0 installed.

Board menu selection
Tools/Board/Arduino Mbed OS RP2040/Raspberry Pi Pico

Seems to work.
As you see it at least builds without error.  As I said, I'm unable to give it a real test.  But that at least looks promising.


60304: <p>I recently bought a Raspberry Pi Pico to play with, and am attempting to upload my first program to it <em>the Arduino way</em>, as my own operating system rather than a c++ program over an existing operating system (meaning to replace the built-in Raspberry Pi Pico operating system which runs MicroPython, not in the sense of running Linux, Windows, Mac, or any derivative or fork). I have not found any record of people hacking it like that - is it possible? If so, how would I go about it? Sorry if this is in the wrong Stack Exchange.</p>
 71205: <p>Here is the library for the Arduino IDE and a Raspberry Pi pico.</p>
<p><a href="https://github.com/lrusak/Arduino-Core-Pico" rel="nofollow noreferrer">https://github.com/lrusak/Arduino-Core-Pico</a></p>
<p>Just install normally as a .zip.</p>
 63711: <p>It is worth mentioning <a href="https://github.com/earlephilhower/arduino-pico" rel="nofollow noreferrer">this excellent alternative</a> to the Arduino one from Earle F. Philhower. It seems well-maintained and doesn't depend on Mbed OS, so it leaves more space (ram and flash) for your application.</p>
<p><a href="https://github.com/earlephilhower/arduino-pico/issues/117#issuecomment-830356795" rel="nofollow noreferrer">Here</a> an informal comparative list.</p>
 70020: <h2>Official support.</h2>
<p>Apparently there's official support for it, now anyway.</p>
<p>I was digging around in the <a href="https://github.com/arduino/ArduinoCore-mbed/" rel="nofollow noreferrer">Arduino-mbed core</a>, trying to help someone else, specifically in the <a href="https://github.com/arduino/ArduinoCore-mbed/blob/2.0.0/boards.txt" rel="nofollow noreferrer">boards.txt</a> and spied the line:</p>
<blockquote>
<p>pico.name=Raspberry Pi Pico</p>
</blockquote>
<p>Unfortunately, I don't have any way to give it a proper test as I don't have one of these.  But I did go so far as to install the core and compile a simple hello world program.</p>
<h2>In boards manager</h2>
<p>Search for &quot;mbed rp2040&quot;; these names sometimes change, but those terms work well now.  You can see in the lower item, I have version 2.0.0 installed.</p>
<p><a href="https://i.stack.imgur.com/CSz4e.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/CSz4e.png" alt="Boards manager dialog shown with search terms &quot;mbed rp2020&quot;" /></a></p>
<h2>Board menu selection</h2>
<p><code>Tools</code>/<code>Board</code>/<code>Arduino Mbed OS RP2040</code>/<code>Raspberry Pi Pico</code></p>
<p><a href="https://i.stack.imgur.com/GvLEf.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/GvLEf.png" alt="Shows Menu with board selected." /></a></p>
<h2>Seems to work.</h2>
<p>As you see it at least builds without error.  As I said, I'm unable to give it a real test.  But that at least looks promising.</p>
<p><a href="https://i.stack.imgur.com/fWqTS.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/fWqTS.png" alt="Shows successful build." /></a></p>
