# Holybro Pixhawk 4 Mini (Discontinued)

<Badge type="info" text="Discontinued" px4_current="v1.15" year="2024"/>

:::warning
PX4 does not manufacture this (or any) autopilot.
Contact the [manufacturer](https://holybro.com/) for hardware support or compliance issues.
:::

The _Pixhawk<sup>&reg;</sup> 4 Mini_ autopilot is designed for engineers and hobbyists who are looking to tap into the power of _Pixhawk 4_ but are working with smaller drones.
_Pixhawk 4 Mini_ takes the FMU processor and memory resources from the _Pixhawk 4_ while eliminating interfaces that are normally unused.
This allows the _Pixhawk 4 Mini_ to be small enough to fit in a 250mm racer drone.

_Pixhawk 4 Mini_ was designed and developed in collaboration with Holybro<sup>&reg;</sup> and Auterion<sup>&reg;</sup>.
It is based on the [Pixhawk](https://pixhawk.org/) **FMUv5** design standard and is optimized to run PX4 flight control software.

![Pixhawk4 mini](../../assets/flight_controller/pixhawk4mini/pixhawk4mini_iso_1.png)

:::tip
This autopilot is [supported](../flight_controller/autopilot_pixhawk_standard.md) by the PX4 maintenance and test teams.
:::

## Quick Summary

- Main FMU Processor: STM32F765
  - 32 Bit Arm® Cortex®-M7, 216MHz, 2MB memory, 512KB RAM
- On-board sensors:
  - Accel/Gyro: ICM-20689
  - Accel/Gyro: BMI055 or ICM20602
  - Magnetometer: IST8310
  - Barometer: MS5611
- GPS: u-blox Neo-M8N GPS/GLONASS receiver; integrated magnetometer IST8310
- Interfaces:
  - 8 PWM outputs
  - 4 dedicated PWM/Capture inputs on FMU
  - Dedicated R/C input for CPPM
  - Dedicated R/C input for Spektrum / DSM and S.Bus with analog / PWM RSSI input
  - 3 general purpose serial ports
  - 2 I2C ports
  - 3 SPI buses
  - 1 CANBuses for CAN ESC
  - Analog inputs for voltage / current of battery
  - 2 additional analog input
- Power System:
  - Power Brick Input: 4.75~5.5V
  - USB Power Input: 4.75~5.25V
  - Servo Rail Input: 0~24V
  - Max current sensing: 120A
- Weight and Dimensions:
  - Weight: 37.2g
  - Dimensions: 38x55x15.5mm
- Other Characteristics:
  - Operating temperature: -40 ~ 85°c

Additional information can be found in the [_Pixhawk 4 Mini_ Technical Data Sheet](https://github.com/PX4/PX4-Autopilot/raw/main/docs/assets/flight_controller/pixhawk4mini/pixhawk4mini_technical_data_sheet.pdf).

## Where to Buy

No longer available.

## Interfaces

![Pixhawk 4 Mini interfaces](../../assets/flight_controller/pixhawk4mini/pixhawk4mini_interfaces.png)

:::warning
The **RC IN** and **PPM** ports are for RC receivers only. These are powered! NEVER connect any servos, power supplies or batteries (or to any connected receiver).
:::

## Pinouts

Download _Pixhawk 4 Mini_ pinouts from [here](https://github.com/PX4/PX4-Autopilot/raw/main/docs/assets/flight_controller/pixhawk4mini/pixhawk4mini_pinouts.pdf).

## Dimensions

![Pixhawk 4 Mini Dimensions](../../assets/flight_controller/pixhawk4mini/pixhawk4mini_dimensions.png)

## Voltage Ratings

_Pixhawk 4 Mini_ can have power supply redundancy — if two power sources are supplied. The power rails are: **POWER** and **USB**.

::: info
The output power rail of **MAIN OUT** does not power the flight controller board (and is not powered by it).
You must [supply power](../assembly/quick_start_pixhawk4_mini.md#power) to one of **POWER** or **USB** or the board will be unpowered.
:::

**Normal Operation Maximum Ratings**

Under these conditions all power sources will be used in this order to power the system:

1. **POWER** (4.75V to 5.5V)
1. **USB** input (4.75V to 5.25V)

**Absolute Maximum Ratings**

Under these conditions the system will remain intact.

1. **POWER** input (0V to 6V undamaged)
1. **USB** input (0V to 6V undamaged)
1. Servo input: VDD_SERVO pin of **MAIN OUT** (0V to 24V undamaged)

## Assembly/Setup

The [_Pixhawk 4 Mini_ Wiring Quick Start](../assembly/quick_start_pixhawk4_mini.md) provides instructions on how to assemble required/important peripherals including GPS, Power Management Board, etc.

## Building Firmware

:::tip
Most users will not need to build this firmware!
It is pre-built and automatically installed by _QGroundControl_ when appropriate hardware is connected.
:::

To [build PX4](../dev_setup/building_px4.md) for this target:

```
make px4_fmu-v5_default
```

## Debug Port

The [PX4 System Console](../debug/system_console.md) and [SWD interface](../debug/swd_debug.md) run on the **FMU Debug** port.
In order to access these ports, the user must remove the _Pixhawk 4 Mini_ casing.

![Pixhawk 4 Mini FMU Debug](../../assets/flight_controller/pixhawk4mini/pixhawk4mini_fmu_debug.png)

The port has a standard serial pinout and can be connected to a standard FTDI cable (3.3V, but it's 5V tolerant) or a [Zubax BugFace BF1](https://github.com/Zubax/bugface_bf1).
The pinout uses the standard [Pixhawk debug connector](https://github.com/pixhawk/Pixhawk-Standards/blob/master/DS-009%20Pixhawk%20Connector%20Standard.pdf) pinout. Please refer to the [wiring](../debug/system_console.md) page for details of how to wire up this port.

## Serial Port Mapping

|  UART  |   Device   | QGC Parameter Description |     Port Label on FC     |
| :----: | :--------: | :-----------------------: | :----------------------: |
| UART1  | /dev/ttyS0 |           GPS1            |        GPS Module        |
| USART2 | /dev/ttyS1 |          TELEM1           |          TELEM1          |
| USART3 | /dev/ttyS2 |          TELEM2           |           N/A            |
| UART4  | /dev/ttyS3 |       TELEM/SERIAL4       |        UART/l2C B        |
| USART6 | /dev/ttyS4 |            N/A            |          RC IN           |
| UART7  | /dev/ttyS5 |            N/A            |          Debug           |
| UART8  | /dev/ttyS6 |            N/A            | Not connected (no PX4IO) |

## Peripherals

- [Digital Airspeed Sensor](https://holybro.com/products/digital-air-speed-sensor-ms4525do)
- [Telemetry Radio Modules](../telemetry/index.md)
- [Rangefinders/Distance sensors](../sensor/rangefinders.md)

## Supported Platforms

Motors and servos are connected to the **MAIN OUT** ports in the order specified for your vehicle in the [Airframe Reference](../airframes/airframe_reference.md).
This reference lists the output port to motor/servo mapping for all supported air and ground frames (if your frame is not listed in the reference then use a "generic" airframe of the correct type).

:::warning
_Pixhawk 4 Mini_ does not have AUX ports.
The board cannot be used with frames that require more than 8 ports or which use AUX ports for motors or control surfaces.
It can be used for airframes that use AUX for non-essential peripherals (e.g. "feed-through of RC AUX1 channel").
:::

## Further info

- [_Pixhawk 4 Mini_ Technical Data Sheet](https://github.com/PX4/PX4-Autopilot/raw/main/docs/assets/flight_controller/pixhawk4mini/pixhawk4mini_technical_data_sheet.pdf)
- [FMUv5 reference design pinout](https://docs.google.com/spreadsheets/d/1-n0__BYDedQrc_2NHqBenG1DNepAgnHpSGglke-QQwY/edit#gid=912976165).
