RP2350 / RP2040 Boards

Arduino IDE Setup

madflight for RP2350/RP2040 requires arduino-pico v4.x.x

Start the Arduino IDE and select menu Tools->Board Manager to install this software.

PlatformIO Setup

Clone or download the madflight repository from GitHub.

Start PlatformIO, press the "Import Arduino Project" button, and import a madflight example.

Adapt the platformio.ini file as follows:

; PlatformIO Project Configuration File for madflight

[env]
; Set this to the folder where madflight.h is located
; Default locations when installed via the Arduino IDE:
;    Windows: C:\Users\{username}\Documents\Arduino\libraries\madflight
;    macOS:   /Users/{username}/Documents/Arduino/libraries/madflight
;    Linux:   /home/{username}/Arduino/libraries/madflight

lib_extra_dirs = /ENTER/MADFLIGHT/FOLDER/HERE

; RP2040/RP2350 is not merged into mainline PlatformIO, see 
; https://arduino-pico.readthedocs.io/en/latest/platformio.html
; on Windows you need to enable long path names, see above link for instructions

[env:madflight_pico]
platform = https://github.com/maxgerhardt/platform-raspberrypi.git
board = pico
framework = arduino
board_build.core = earlephilhower

[env:madflight_pico2]
platform = https://github.com/maxgerhardt/platform-raspberrypi.git
board = rpipico2
framework = arduino
board_build.core = earlephilhower

Pinout Raspberry Pi Pico2 / Raspberry Pi Pico

This is the default pinout for RP2350 and RP2040. It is optimized for Raspberry Pi Pico2 / Raspberry Pi Pico (40 pin) boards. This pinout is defined in madflight_board_default_RP2040.h, but can be modified with #define HW_PIN_xxx in your program.

Module <-> HW_PIN_xxx	GPIO	Board	GPIO	HW_PIN_xxx <-> Module
Radio RX <- RCIN_TX	0	USB connector	VBUS	nc
Radio TX -> RCIN_RX	1		VSYS	5V input via diode (*)
GND	GND		GND	GND
ESC/Servo <- PWM1	2		EN	nc
ESC/Servo <- PWM2	3		3.3V out	3V3
ESC/Servo <- PWM3	4		VREF	nc
ESC/Servo <- PWM4	5		28_A2	BAT_V <- Battery voltage divider
GND	GND		GND	GND
ESC/Servo <- PWM5	6		27_A1	-
ESC/Servo <- PWM6	7		26_A0	-
GPS Receiver RX <- GPS_TX	8		RUN	reset button to GND
GPS Receiver TX -> GPS_RX	9		22	IMU_EXTI <- IMU interrupt
GND	GND		GND	GND
ESC/Servo <- PWM7	10		21	I2C_SCL -> Barometer, magnetometer, etc.
ESC/Servo <- PWM8	11		20	I2C_SDA <-> Barometer, magnetometer, etc.
SDCARD -> SPI2_MISO	12		19	SPI_MOSI -> IMU
SDCARD <- BB_CS	13		18	SPI_SCLK -> IMU
GND	GND		GND	GND
SDCARD <- SPI2_SCLK	14		17	IMU_CS -> IMU
SDCARD <- SPI2_MOSI	15	JTAG pins	16	SPI_MISO <- IMU

(*) 5V input via diode from BEC. Without a diode take care not connect USB and the battery at the same time!

Pinout RP2040-Zero

This pinout is optimized for the RP2040-Zero (21 pin) board. This pinout is defined in madflight_board_RP2040-Zero.h, but can be modified with #define HW_PIN_XXX in your program.

Function	GPIO	Board	GPIO	Function
5V input (*)	5V	USB connector	0	RCIN_TX
GND	GND		1	RCIN_RX
3V3 out	3V3		2	PWM1
-	29		3	PWM2
BAT_V	28		4	PWM3
I2C1_SCL	27		5	PWM4
I2C1_SDA	26		6	PWM5
IMU_EXTI	15		7	PWM6
	14		8	GPS_TX
			9	GPS_RX
			10	SPI1_SCLK
			11	SPI1_MISO
			12	SPI1_MOSI
			13	IMU_CS

(*) 5V input via diode from BEC. Without a diode take care not connect USB and the battery at the same time!

RP2350/RP2040 Hardware

RP2350 (Raspberry Pi Pico2) is newer and a lot more powerful than RP2040 (Raspberry Pi Pico).

Dual Core / FPU

RP2350 has dual core, dual single precision FPU.

RP2040 has dual core, no FPU.

madflight uses float and is much happier with RP2350 than with RP2040 !

FreeRTOS

FreeRTOS is optional.

PWM

Consecutive even/odd PWM pins (e.g. pins 2,3 or 10,11) share the same timer and have the same frequency.

Serial

madflight uses a custom high performance SerialIRQ library.

madflight for RP2040

madflight for RP2040 uses FreeRTOS and executes the 1000Hz IMU loop on the second core, which is 80% loaded at default 133MHz CPU speed. You can overclock the CPU to get some more headroom.

madflight for RP2350