mRo Pixracer (FMUv4)
Last updated
Last updated
:::warning PX4 does not manufacture this (or any) autopilot. Contact the manufacturer for hardware support or compliance issues. :::
The Pixhawk® XRacer board family is optimized for small racing quads and planes. In contrast to Pixfalcon and Pixhawk it has in-built WiFi, new sensors, convenient full servo headers, CAN and supports 2M flash.
:::tip This autopilot is supported by the PX4 maintenance and test teams. :::
Main System-on-Chip: STM32F427VIT6 rev.3
CPU: 180 MHz ARM Cortex® M4 with single-precision FPU
RAM: 256 KB SRAM (L1)
Standard FPV form factor: 36x36 mm with standard 30.5 mm hole pattern
Invensense® ICM-20608 Accel / Gyro (4 KHz) / MPU9250 Accel / Gyro / Mag (4 KHz)
HMC5983 magnetometer with temperature compensation
Measurement Specialties MS5611 barometer
JST GH connectors
microSD (logging)
Futaba S.BUS and S.BUS2 / Spektrum DSM2 and DSMX / Graupner SUMD / PPM input / Yuneec ST24
FrSky® telemetry port
OneShot PWM out (configurable)
Optional: Safety switch and buzzer
Pixracer is available from the mRobotics.io.
Accessories include:
The Pixracer is designed to use a separate avionics power supply. This is necessary to avoid current surges from motors or ESCs to flow back to the flight controller and disturb its delicate sensors.
Power module (with voltage and current sensing)
I2C splitter (supporting AUAV, Hobbyking and 3DR® peripherals)
Cable kit for all common peripherals
One of the main features of the board is its ability to use Wifi for flashing new firmware, system setup and in-flight telemetry. This frees it of the need of any desktop system.
:::note Firmware upgrade is not yet enabled over WiFi (it is supported by the default bootloader but not yet enabled). Setup and telemetry are supported. :::
See the Pixracer Wiring Quickstart
:::note If using TELEM2 for an external telemetry module you will need to configure it as a MAVLink serial port. For more information see: Pixracer Wiring Quickstart > External Telemetry :::
All connectors follow the Pixhawk connector standard. Unless noted otherwise all connectors are JST GH.
1 (red)
VCC
+5V
2 (blk)
TX (OUT)
+3.3V
3 (blk)
RX (IN)
+3.3V
4 (blk)
CTS (IN)
+3.3V
5 (blk)
RTS (OUT)
+3.3V
6 (blk)
GND
GND
1 (red)
VCC
+5V
2 (blk)
TX (OUT)
+3.3V
3 (blk)
RX (IN)
+3.3V
4 (blk)
I2C1 SCL
+3.3V
5 (blk)
I2C1 SDA
+3.3V
6 (blk)
GND
GND
1 (red)
VCC
+5V
2 (blk)
TX (OUT)
+3.3V
3 (blk)
RX (IN)
+3.3V
4 (blk)
GND
GND
1 (red)
VCC
+5V
2 (blk)
RC IN
+3.3V
3 (blk)
RSSI IN
+3.3V
4 (blk)
VDD 3V3
+3.3V
5 (blk)
GND
GND
1 (red)
VCC
+5V
2 (blk)
CAN_H
+12V
3 (blk)
CAN_L
+12V
4 (blk)
GND
GND
1 (red)
VCC
+5V
2 (blk)
VCC
+5V
3 (blk)
CURRENT
+3.3V
4 (blk)
VOLTAGE
+3.3V
5 (blk)
GND
GND
6 (blk)
GND
GND
1 (red)
SAFETY
GND
2 (blk)
!IO_LED_SAFETY
GND
3 (blk)
VCC
+3.3V
4 (blk)
BUZZER-
-
5 (blk)
BUZZER+
-
The pinouts and connector comply with the Pixhawk Debug Mini interface defined in the Pixhawk Connector Standard (JST SM06B connector).
1 (red)
VCC TARGET SHIFT
+3.3V
2 (blk)
CONSOLE TX (OUT)
+3.3V
3 (blk)
CONSOLE RX (IN)
+3.3V
4 (blk)
SWDIO
+3.3V
5 (blk)
SWCLK
+3.3V
6 (blk)
GND
GND
For information about using this port see:
PX4 System Console (Note, the FMU console maps to UART7).
UART1
/dev/ttyS0
WiFi (ESP8266)
USART2
/dev/ttyS1
TELEM1 (flow control)
USART3
/dev/ttyS2
TELEM2 (flow control)
UART4
UART7
CONSOLE
UART8
SERIAL4
The reference is provided as: Altium Design Files
The following PDF files are provided for convenience only:
pixracer-r14.pdf - R14 or RC14 is printed next to the SDCard socket
:::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 for this target:
Compass calibration should be done with USB disconnected. This is always recommended, but is necessary on Pixracer because the USB connection produces particularly large levels of magnetic interference.
Configuration is otherwise the same as for other boards.
This design was created by Nick Arsov and Phillip Kocmoud and architected by Lorenz Meier, David Sidrane and Leonard Hall.
