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How to Create a Flight Controller Configuration File for Betaflight 4.5

Under construction.

This document describes how to create a flight controller configuration file for Betaflight 4.5 and is a work in progress.

Introduction​

Firmware 4.5 no longer uses unified-targets but instead uses a configuration file for each flight controller. This guide will walk you through the process of creating a configuration file.

Overview​

  1. Create a new configuration file in the config repository.
  2. The configuration file consists of defines and is independant from using CLI commands. All defines are in the format #define <setting> [value].
  3. Other directives can be used in the configuration file, e.g. #ifdef, #else and #endif.

Configuration​

License Information​

The license information is used to identify the license of the firmware. The configuration file needs to start with:

/*
 * This file is part of Betaflight.
 *
 * Betaflight is free software. You can redistribute this software
 * and/or modify this software under the terms of the GNU General
 * Public License as published by the Free Software Foundation,
 * either version 3 of the License, or (at your option) any later
 * version.
 *
 * Betaflight is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this software.
 *
 * If not, see <http://www.gnu.org/licenses/>.
 */

#pragma once

Board Configuration​

#define FC_TARGET_MCU ATF435M
#define BOARD_NAME AIRBOTF435
#define MANUFACTURER_ID AIRB

Hardware Defines​

For a list of hardware defines please see [Hardware Defines](manufacturer-design-guidelines## 4.2 Definitions for Targets)

Pin Resources​

The pin resources are used to configure the pins on the flight controller.

Timer and Dma Resources​

The timer and DMA resources are used to configure the timers and DMA on the flight controller. Configure the timer in CLI:

Example using a STM32F722:

#timer
timer A00 AF2
# pin A00: TIM5 CH1 (AF2)
timer A01 AF2
# pin A01: TIM5 CH2 (AF2)
timer A02 AF2
# pin A02: TIM5 CH3 (AF2)
timer A03 AF2
# pin A03: TIM5 CH4 (AF2)
timer B00 AF2
# pin B00: TIM3 CH3 (AF2)
timer B01 AF2
# pin B01: TIM3 CH4 (AF2)
timer C07 AF3
# pin C07: TIM8 CH2 (AF3)
timer C08 AF3
# pin C08: TIM8 CH3 (AF3)
timer C09 AF3
# pin C09: TIM8 CH4 (AF3)

Also set the DMA options, so the command timer map outputs the right values, else they will be -1 for dmaopt (which is unused).

e.g.

dma pin A01 0
# pin A01: DMA1 Stream 4 Channel 6
dma pin A00 0
# pin A00: DMA1 Stream 2 Channel 6

The below is an example of the output after running timer map in CLI:

#timer map

Timer Mapping:
    TIMER_PIN_MAP(0, PA0, 2, 0)
    TIMER_PIN_MAP(1, PA1, 2, 0)
    TIMER_PIN_MAP(2, PA2, 2, -1)
    TIMER_PIN_MAP(3, PA3, 2, -1)
    TIMER_PIN_MAP(4, PB0, 2, 0)
    TIMER_PIN_MAP(5, PB1, 2, 0)
    TIMER_PIN_MAP(6, PC7, 2, -1)
    TIMER_PIN_MAP(7, PC8, 2, -1)
    TIMER_PIN_MAP(8, PC9, 2, -1)

To enable the timer map command you need to add the define USE_TIMER_MAP_PRINT so use either:

make TARGET EXTRA_FLAGS="-DUSE_TIMER_MAP_PRINT"

The TIMER_PIN_MAP config statement is broken down as follows:

TIMER_PIN_MAP(WW, XX, YY, ZZ)

  • WW - zero-indexed counter, increment by 1 for each line in the timer map
  • XX - pin number to set the timer on
  • YY - selected instance of the timer configuration where multiple options are available. See your MCU's target timer code for the list of options. For example F772 should reference this timer file.
  • ZZ - DMA setting for that timer, same number as used in the dma pin <pin number> <dma> command.

Serial Configuration​

The serial configuration is used to configure the serial ports on the flight controller. The following defines are available:

ValueFunction define
1MSP_UART
2GPS_UART
64SERIALRX_UART
32SBUS_TELEMETRY_UART
1024ESC_SENSOR_UART
2048VTX_SMARTAUDIO_UART
8192VTX_TRAMP_UART
131072VTX_MSP_UART
131073MSP_DISPLAYPORT_UART

The following example shows how to configure the serial ports for receiver, GPS and SmartAudio VTX.

#define SERIALRX_UART SERIAL_PORT_USART1
#define VTX_SMARTAUDIO_UART SERIAL_PORT_USART3
#define GPS_UART SERIAL_PORT_USART4
note

Serial command is zero index based, so the first serial port is SERIAL_PORT_USART1 and not SERIAL_PORT_USART0.


The USART is meant to do all of the “heavy lifting” serial communication during periods of “high” energy consumption.


When the microcontroller is asleep and in a low power mode, though, the UART peripheral can handle low speed communications while offering a reduced energy footprint. Betaflight has UART4, UART5 and UART9. Other serial ports are USUART as some boards provide LPUART1

Serial Receiver Provider​

BNF boards may want to configure the serial receiver provider on the flight controller. Example:

#define SERIALRX_PROVIDER CRSF

ADC Configuration​

The ADC configuration is used to configure the ADC on the flight controller.

Bus Configuration​

The bus configuration is used to configure the I2C and SPI buses on the flight controller.

LED Configuration​

The LED configuration is used to configure the LED on the flight controller.

OSD Configuration​

The OSD configuration is used to configure the OSD on the flight controller.

VTX Configuration​

The VTX configuration is used to configure the VTX on the flight controller.