README.md

Robomaster

RoboMaster is a C++ library designed to control the DJI RoboMaster via a direct CAN Bus interface, allowing users to use the RoboMaster chassis as a mobile robotics platform without the Intelli Controller. By communicating directly over CAN Bus, the need for Wi-Fi, USB, or other intermediary connections is eliminated, reducing latency and complexity. The library provides a simple C++ API and requires a computer with a CAN Bus interface, such as an NVIDIA Jetson board or a Raspberry Pi with a CAN Bus module. Additionally, the 12V power supply from the CAN Bus can be used as a power source for the RoboMaster.

Caution: it is recommended to send commands only every 10–20 milliseconds to not overflow the CAN Bus, otherwise the RoboMaster can behave unintentionally.

Original Library

This library was original provided by Fraunhofer IML130 and can be found here: Robomaster Can Controller. This repo contains a modified version for my personal needs. I've added missing features like Gimbal and Blaster control.

C++ Version:

Build and Install

Build the library and use the given example to test the library on the RoboMaster.

cd robomaster
mkdir build
cd build
cmake ..
make && sudo make install

Run the example in the build directory. Give the RoboMaster enough space to drive or put the Robomaster on a box that the wheels don't touch the ground.

./robomaster_demo

Class RoboMaster

The class RoboMaster provides simple access to control the chassis, the gimbal, the blaster and the LEDs.

Method	Description
bool init(std::string& interface)	Initialize the RoboMaster by opening the CAN bus by the given can_interface and set CAN receiving. Return true on success.
bool is_running()	Return true when the RoboMaster is successfully initialized and running. Switch to false when an error occurs.
RoboMasterState get_state()	Return the current RoboMasterState this is frequently updated.
void set_chassis_mode(ChassisMode mode)	Set the RoboMaster's ChassisMode (Enable or Disable.
void set_chassis_rpm(int16_t front_right, int16_t front_left, int16_t rear_left, int16_t rear_right)	Set the wheel speed in rpm in the wheel order front right, front left, rear left and rear right [-1000, 1000].
void set_chassis_velocity(float pitch, float yaw, float roll)	Set the pitch, yaw and angular roll velocity. The velocity and acceleration limits are handled by the config of the motion controller.
void set_chassis_position(int16_t linear_x, int16_t linear_y, int16_t angular_z)	Set the chassis position for linear x, linear y [-500, 500] and angular z [-18000, 18000].
void set_gimbal_mode(GimbalMode mode)	Set the RoboMaster's GimbalMode (Free or Follow).
void set_gimbal_hibernate(GimbalState state)	Set the GimbalHibernate (Suspend or Resume).
void set_gimbal_motion(int16_t pitch, int16_t yaw)	Set the pitch and yaw degree's for the gimbal [-1000, 1000].
void set_gimbal_velocity(int16_t pitch, int16_t yaw)	Set the yaw and roll velocity for the gimbal [-1000, 1000].
void set_gimbal_position(int16_t pitch, int16_t yaw, uint16_t pitch_acceleration, uint16_t yaw_acceleration)	Set the gimbal position for pitch [-500, 500] and yaw [-2500, 2500].
void set_gimbal_recenter(int16_t pitch, int16_t yaw)	Set the gimbal back to center position [10, 500].
void set_blaster_mode(BlasterMode mode, uint8_t count)	Set the BlasterMode and fire the blaster [1, 8] times based on the given count.
void set_led_mode(LEDMode mode, LEDMask mask, uint8_t red, uint8_t green, uint8_t blue, uint16_t up_time, uint16_t down_time	Set the LEDMode and LEDMask, the color for Red, Green and Blue and the up and down time for some modes.

Struct RoboMasterState

Information of the state of the RoboMaster Chassis.

struct (C++)	Description
StateBattery battery	Contains the state of the RoboMaster battery.
StateESC esc	Contains the states of the wheels.
StateIMU imu	Contains the sensor data of the IMU in the motion controller.
StateVelocity velocity	Contains the estimated velocities of the RoboMaster from the motion controller.
StatePosition position	Contains the odometry data of the motion controller.
StateAttitude attitude	Contains the attitude of the RoboMaster estimated from the motion controller.
StateGimbal gimbal	Contains the state of the RoboMaster gimbal.
StateDetector detector[4]	Contains the states of the RoboMaster hit detector's.

Struct StateBattery

Information of the RoboMaster battery.

Name	datatype	Description
adc	uint16_t	ADC value of the battery in milli volts.
temperature	int16_t	Temperature in 10*e-1
current	int32_t	Current in milli amperes.
percent	uint8_t	Percent of the battery [0, 100].
recv	uint8_t	N/A

Struct StateESC

Information of the state of the wheels. The wheel order in the arrays is front left, front right, rear left and rear right

Name	datatype	Description
speed	int16_t[4]	Speed in RPM -> value range -8192~8191.
angle	int16_t[4]	Angle position -> value range 0-32767 maps to -> 0-360.
speed	uint32_t[4]	Timestamp -> units N/A
speed	uint8_t[4]	State of the ESC -> units N/A

Struct StateIMU

Information of the measured sensor data from the IMU in the Motion Controller.

Name	datatype	Description
acc_x	float	Acceleration on x axis in 9.81 /m^2 s.
acc_y	float	Acceleration on y axis in 9.81 /m^2 s.
acc_z	float	Acceleration on x axis in 9.81 /m^2 s.
gyro_x	float	Angular velocity on x axis in radiant.
gyro_y	float	Angular velocity on y axis in radiant.
gyro_z	float	Angular velocity on z axis in radiant.

Struct StateVelocity

Information of the chassis velocities which are measured from the Motion Controller.

Name	datatype	Description
vgx	float	Velocity m/s on the x axis in the global coordinate system where the RoboMaster is turned on.
vgy	float	Velocity m/s on the y axis in the global coordinate system where the RoboMaster is turned on.
vgz	float	Velocity m/s on the z axis in the global coordinate system where the RoboMaster is turned on. Is always 0.0.
vbx	float	Velocity m/s on the x axis in local coordinate system.
vby	float	Velocity m/s on the y axis in local coordinate system.
vbz	float	Velocity m/s on the z axis in local coordinate system.. Is always 0.0.

Struct StatePosition

Information of the measured position of the RoboMaster since the RoboMaster is powered on.

Name	datatype	Description
pos_x	float	X position on the x axis in the global coordinate system where the RoboMaster is turned on.
pos_y	float	Y position on the x axis in the global coordinate system where the RoboMaster is turned on.
pos_z	float	Z position on the x axis in the global coordinate system where the RoboMaster is turned on. Is always 0.0.

Struct StateAttitude

Information of the Attitude which is measured by the Motion Controller.

Name	datatype	Description
roll	float	Roll in degree
pitch	float	Pitch in degree.
yaw	float	Yaw in degree.

Struct StateGimbal

Information of the Attitude which is measured by the Gimbal.

Name	datatype	Description
pitch	int16_t	Pitch in degree.
yaw	int16_t	Yaw in degree.

Struct StateDetector

Information of the last Hit which is measured by the Hit detector.

Name	datatype	Description
hit_time	time_point	Timestamp of the latest hit.
intensity	uint16_t	Intensity of the latest hit.