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Flight Core Functional Description

Table of contents

  1. Flight Core Functional Description
    1. Overview
    2. Dimensions
      1. 3D Drawings
      2. 2D Drawings
    3. Features
    4. Block Diagram
    5. Orientation
    6. Power Supply
      1. Recommended
      2. Power Usage


ModalAI Flight Core is a PX4 flight controller that uses a very similar architecture to FMUv5x. It’s design goal is to be software compatible with the FMUv5x architecture in a smaller Pixracer-style form factor.


3D Drawings


2D Drawings

flight-core-dims.png flight_core_v1_imu_locations.png


Weight6 g
MCU216MHz, 32-bit ARM M7 STM32F765II
Memory256Kb FRAM
 2Mbit Flash
 512Kbit SRAM
IMUsICM-20602 (SPI1)
 ICM-42688-P (SPI2)
 BMI088 (SPI6)
BarometerBMP388 (I2C4)
Secure ElementA71CH (I2C4)
microSD CardPX4 Supported SD Cards SDHC version 2 up to 32GB
 CAN bus
Outputs6 LEDs (2xRGB)
 8 PWM Channels
Extra Interfaces3 serial ports


Block Diagram

fc-dk-preliminary-datasheet.png Figure 1



The following is a ‘top down’ view of the Flight Core depicting the orientation. Starting in PX4 v1.11, the orientation is updated to better align with the usage of the VOXL-Flight. The following is a ‘top down’ view of the Flight Core depicting a ROTATION_NONE setup.

PX4 VersionOrientation to Achieve ForwardBranchNotes
1.10ROTATION_YAW_180relesase/1.10Not Recommended
masterROTATION_NONEmasterIn Development

Flight Core Orientation

Power Supply

A 5VDC supply is required to power the Flight Core. The FC-PM Power Module board is recommended, which provides battery voltage and amperage monitoring through an I2C interface when connected to J6 using the MCBL-00003 cable.

Other connectors also allow a 5VDC supply to be connected (see connectors page )

  • J6 - recommended, provides I2C interace for monitoring
  • J1/J4/J5

Power Usage

NOTE: The following is preliminary data.

Test configuration:

  • Using a 5VDC supply
  • Using PX4 this commit
Use CaseTypical Usage (Peak)
Idle180 mA
Idle, with GPS (HolyBro Pixhawk 4, Second GPS)260 mA
Idle, with Spektrum DSMX200 mA
Idle, with Holybro Telemetry230 mA
Idle, with GPS/Spektrum/Telemetry330 mA


Pixhawk is a registered trademark of Lorenz Meier.

Next: Flight Core Connectors