MyCobot 280 M5 - MATLAB Interface

MATLAB class for controlling the Elephant Robotics myCobot 280 M5 robotic arm via serial UART.

Hardware

• Robot: myCobot 280 M5 (6-DOF, 280mm reach, 250g payload)
• Controller: M5Stack Basic (base) + M5Stack Atom (end-effector)
• Connection: USB-C serial (CH9102 chip), 115200 baud
• Firmware: M5Stack Basic must be running Transponder mode

Joint Limits

Measured safe operating ranges for this unit:

Joint	Min	Max
J1	-140	+150
J2	-90	+90
J3	-145	+150
J4	-90	+90
J5	-145	+150
J6	-175	+175

Angles outside these ranges are rejected by the class before sending to the robot.

Quick Start

% Connect
myc = MyCobot280('COM13', 'BaudRate', 115200);
myc.powerOn();
pause(1);

% Read current state
myc.getAngles()    % [j1 j2 j3 j4 j5 j6] in degrees
myc.getCoords()    % [x y z rx ry rz] in mm/degrees

% Move joints
myc.sendAngles([0 0 0 0 0 0], 20);   % home position, speed 20
pause(3);
myc.sendAngle(1, 45, 25);            % J1 to 45 degrees

% Cartesian move
myc.sendCoords([160 0 200 0 0 0], 20, 1);  % linear mode

% Gripper
myc.setGripperState(0, 30);   % open
myc.setGripperState(1, 30);   % close

% LED
myc.setColor(0, 255, 0);      % green

% Free move (release servos)
myc.setFreeMove(true);

% Disconnect
myc.powerOff();
delete(myc);

Constructor Options

myc = MyCobot280(port, Name, Value)

Parameter	Default	Description
BaudRate	115200	Serial baud rate
Timeout	5	Read timeout in seconds
Debug	false	Print TX/RX bytes to console
MaxRetries	3	Retry count on communication failure
CommandDelay	0.05	Minimum delay between commands (seconds)

API Reference

Power & Status

Method	Description
powerOn()	Power on the robot
powerOff()	Power off the robot
isPoweredOn()	Check if powered on
isControllerConnected()	Check controller connection
isReady()	Check if robot responds
isMoving()	Check if currently moving

Joint Control

Method	Description
getAngles()	Get all joint angles (1x6 degrees)
sendAngle(joint, angle, speed)	Move single joint (1-6)
sendAngles(angles, speed)	Move all joints (1x6 vector)
waitForIdle(timeout)	Block until motion completes

Cartesian Control

Method	Description
getCoords()	Get end-effector pose [x y z rx ry rz]
sendCoord(axis, value, speed)	Move single axis (1-6)
sendCoords(coords, speed, mode)	Move to pose (mode: 0=angular, 1=linear)

Jog Control

Method	Description
jogAngle(joint, direction, speed)	Jog joint (direction: 0/1)
jogCoord(axis, direction, speed)	Jog axis (direction: 0/1)
jogStop()	Stop jogging

Gripper

Method	Description
getGripperValue()	Read gripper opening (0-100)
setGripperState(state, speed)	Open (0) or close (1)
setGripperValue(value, speed)	Set specific opening (0-100)
isGripperMoving()	Check if gripper is moving

Servo Control

Method	Description
isServoEnabled(joint)	Check if servo is enabled
isAllServoEnabled()	Check all servos
focusServo(joint)	Power on a servo
releaseServo(joint)	Power off a servo
setFreeMove(enable)	Enable/disable free move mode

LED & IO

Method	Description
setColor(r, g, b)	Set Atom LED color (0-255 each)
setPinMode(pin, mode)	Set pin mode (0=input, 1=output)
setDigitalOutput(pin, level)	Set digital output
getDigitalInput(pin)	Read digital input

Coordinate Frames

Method	Description
setToolReference(coords)	Set tool coordinate system
getToolReference()	Get tool coordinate system
setReferenceFrame(type)	Set frame (0=base, 1=world)
setEndType(type)	Set end type (0=flange, 1=tool)

Protocol

Communication uses a binary serial protocol:

[0xFE] [0xFE] [LEN] [CMD] [DATA...] [0xFA]
  header        |     |       |       footer
              length  cmd   payload

• Angles are encoded as signed 16-bit big-endian, multiplied by 100
• XYZ coordinates are multiplied by 10, rotations by 100
• The class implements retry logic (up to 3 attempts) and frame re-synchronization to recover from communication errors

Files

File	Description
MyCobot280.m	Main MATLAB class
test_joint_limits.m	Joint limit validation test
pymycobot/	Elephant Robotics Python SDK (reference)

Requirements

• MATLAB R2019b or later (uses serialport)
• myCobot 280 M5 with Transponder firmware on M5Stack Basic
• USB-C cable to robot base