Now that you've set up the Arduino IDE with the Philhower RP2040 Arduino core, you're ready to start using Arduino with your RP2040.

RP2040 Arduino Pins

There is no pin remapping for Arduino on the RP2040. Therefore, the pin names on the top of the board are not the pin names used for Arduino. The Arduino pin names are the RP2040 GPIO pin names.

To find the Arduino pin name, check the PrettyPins diagram found on the Pinouts page. Each GPIO pin in the diagram has a GPIOx pin name listed, where x is the pin number. The Arduino pin name is the number following GPIO. For example, GPIO1 would be Arduino pin 1.

The Feather RP2040 USB Host has the GPIO pin names listed on the back of the board as x, where x is the pin number. So, for example, pin 5 would be Arduino pin 5.

Choose Your Board

Navigate to the Tools > Boards > Raspberry Pi RP2040 Boards menu. The Raspberry PI RP2040 Boards menu name may be followed by a version number.

Choose Feather RP2040 USB Host from the menu.

Load the Blink Sketch

Begin by plugging in your board to your computer, and wait a moment for it to be recognised by the OS. It will create a COM/serial port that you can now select from the Tools > Port menu dropdown.

Open the Blink sketch by clicking through File > Examples > 01.Basics > Blink.

Click Upload. A successful upload will result in text similar to the following.

Once complete, the little red LED will begin blinking once every second! Try changing up the delay() timing to change the rate at which the LED blinks.

Manually Enter the Bootloader

If you get into a state with the bootloader where you can no longer upload a sketch, or you have uploaded code that crashes and doesn't auto-reboot into the bootloader, you may have to manually enter the bootloader.

To enter the bootloader, hold down the BOOT button, and while continuing to hold it (don't let go!), press and release the reset button. Continue to hold the BOOT button until the RPI-RP2 drive appears!

Once the RPI-RP2 drive shows up, your board is in bootloader mode. There will not be a port available in bootloader mode, this is expected.

Once you see RPI-RP2 drive, make sure you are no longer holding down any buttons (reset or boot0 button).

Now, click Upload on your sketch to try again.