RP2350B-Flight-controller


Ultra-compact flight controller for mini quadcopters, based on RP2350B MCU.
Board size: 30.5 × 39.8 mm, yet includes IMU, radio module, motor drivers, and full USB power support.

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Key Features


  • MCU: RP2350B (dual-core, PIO, USB device)
  • IMU: LSM6DS3 (accelerometer + gyroscope, SPI connection)
  • Radio module: NRF24L01 + RFX2401C PA/LNA amplifier
  • Motors: 4× brushed DC motors (up to 5 A per channel, short peak)
  • USB-powered flight possible (low-current motors, enough supply over USB)
  • Additional expansion pins (GPIO3–16 + SWD) for sensors, debugging, or add-ons

Pin Mapping


IMU (LSM6DS3) — SPI2


RP2350B GPIOSignalNotes
GPIO19SPI2_MISOSensor data out
GPIO22SPI2_MOSISensor data in
GPIO23SPI2_SCKSPI clock
GPIO20IMU_INT1Interrupt 1
GPIO21IMU_INT2Interrupt 2

Radio Module (NRF24L01 + RFX2401C)


RP2350B GPIOSignalNotes
GPIO28SPI_MOSIShared SPI bus
GPIO36SPI_MISOShared SPI bus
GPIO37SPI_SCKShared SPI bus
GPIO30NRF_CSChip select
GPIO31NRF_CEEnable
GPIO32NRF_IRQInterrupt

Motors


RP2350B GPIOOutputNotes
GPIO45Motor_1Brushed motor driver
GPIO46Motor_2Brushed motor driver
GPIO47Motor_3Brushed motor driver
GPIO48Motor_4Brushed motor driver
GPIO49Motor_currentCurrent sense
GPIO52Motor_voltageBattery/rail voltage sense

LEDs


RP2350B GPIOSignalNotes
GPIO17LED1Status LED
GPIO18LED2Status LED

Debug / Expansion


  • SWD interface exposed for programming/debugging
  • GPIO3–16 free for custom extensions (I²C, UART, SPI, PWM, ADC etc.)

Power


  • Powered from USB or external battery
  • USB can sustain hover/low-thrust operation with small coreless motors
  • Onboard regulation for MCU, IMU, radio, and motor supply

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Use Case


  • Designed for tiny brushed quadcopters and robotics experiments
  • Combines motion sensing, wireless control, and motor drivers in one small board
  • Fits into custom drone frames without extra breakout boards

Quick Start


  1. Connect via USB-C for firmware flashing and testing.
  2. Flash firmware (e.g. custom flight stack on RP2350B).
  3. Connect brushed motors to outputs GPIO45–48.
  4. Pair radio link via NRF24L01 (with RFX2401C amp).
  5. Power from USB for tests, or from LiPo for flight.

Notes


  • Motor channels rated for 5 A peak per motor (coreless brushed).
  • Ensure airflow for heat dissipation at higher loads.
  • Expansion pins allow integration of GPS, barometer, or additional sensors.

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