init

ev3-robotic-arm-master/robotarmmovement/tests/test01_master.py

@@ -0,0 +1,795 @@
+#!/usr/bin/env pybricks-micropython
+
+from math import cos, pi
+
+from pybricks.hubs import EV3Brick
+from pybricks.ev3devices import Motor
+from pybricks.parameters import Port, Stop
+from pybricks.tools import wait, StopWatch
+from pybricks.messaging import BluetoothMailboxClient, TextMailbox
+
+
+# ============================================================
+# MASTER BRICK PROGRAM
+# ============================================================
+#
+# Run slave_main.py FIRST.
+# Then run this master program.
+#
+# Master:
+#   - connects to slave,
+#   - sends full slave-side movement plan,
+#   - waits for READY,
+#   - sends GO,
+#   - executes master-side local joints,
+#   - waits for slave DONE.
+#
+# This avoids sending per-joint commands during the movement itself.
+
+
+# ============================================================
+# BLUETOOTH SETTINGS
+# ============================================================
+
+# Change this to the Bluetooth name of your slave EV3.
+# By default many EV3 bricks are named 'ev3dev'.
+SLAVE_BRICK_NAME = 'ev3armslave'
+
+# Optional delay after sending GO before master starts its own local movement.
+#
+# Bluetooth mailboxes are not hard real-time. If your measurements show that
+# master starts earlier than slave, increase this value slightly.
+#
+# Start with 0. Later calibrate using camera/audio/LED timestamps.
+MASTER_START_DELAY_AFTER_GO_MS = 0
+
+
+# ============================================================
+# MASTER JOINT PORTS
+# ============================================================
+
+BASE_PORT = Port.A
+SHOULDER_LEFT_PORT = Port.B
+SHOULDER_RIGHT_PORT = Port.C
+ELBOW_PORT = Port.D
+
+
+# ============================================================
+# MOTION SETTINGS
+# ============================================================
+
+DEFAULT_SPEED = 200
+PROFILE_UPDATE_MS = 20
+POLL_MS = 10
+
+DEFAULT_EASING = 'linear'
+CLAMP_EASING_OUTPUT = True
+
+DEADBAND_MOTOR_DEG = 1.5
+TRACK_TARGET_MIN_UPDATE_MOTOR_DEG = 1.0
+
+SOUND_ENABLED = True
+
+
+# ============================================================
+# MASTER JOINT CONFIGURATION
+# ============================================================
+
+GEAR_RATIOS = {
+    'base': 7.5,
+    'shoulder': 7.5,
+    'elbow': 5.0,
+}
+
+JOINT_LIMITS = {
+    'base': None,
+    'shoulder': None,
+    'elbow': None,
+}
+
+SHOULDER_SIGNS = [1, 1]
+
+STOP_MODE_BY_JOINT = {
+    'base': Stop.BRAKE,
+    'shoulder': Stop.BRAKE,
+    'elbow': Stop.BRAKE,
+}
+
+
+# ============================================================
+# HARDWARE / BLUETOOTH
+# ============================================================
+
+ev3 = EV3Brick()
+
+base_motor = Motor(BASE_PORT)
+shoulder_left_motor = Motor(SHOULDER_LEFT_PORT)
+shoulder_right_motor = Motor(SHOULDER_RIGHT_PORT)
+elbow_motor = Motor(ELBOW_PORT)
+
+client = BluetoothMailboxClient()
+cmd_box = TextMailbox('command', client)
+status_box = TextMailbox('status', client)
+
+
+# ============================================================
+# UTILITIES
+# ============================================================
+
+def clamp(value, min_value, max_value):
+    if value < min_value:
+        return min_value
+    if value > max_value:
+        return max_value
+    return value
+
+
+def abs_value(value):
+    if value < 0:
+        return -value
+    return value
+
+
+def beep_ok():
+    if SOUND_ENABLED:
+        ev3.speaker.beep(frequency=1000, duration=80)
+
+
+def beep_error():
+    if SOUND_ENABLED:
+        ev3.speaker.beep(frequency=220, duration=200)
+        wait(80)
+        ev3.speaker.beep(frequency=220, duration=200)
+
+
+def beep_start_marker():
+    if SOUND_ENABLED:
+        ev3.speaker.beep(frequency=1400, duration=60)
+
+
+# ============================================================
+# EASING FUNCTIONS
+# ============================================================
+
+def ease_linear(x):
+    return x
+
+
+def ease_in_out_sine(x):
+    return -(cos(pi * x) - 1) / 2
+
+
+def ease_in_out_quad(x):
+    if x < 0.5:
+        return 2 * x * x
+    return 1 - ((-2 * x + 2) ** 2) / 2
+
+
+def ease_in_out_cubic(x):
+    if x < 0.5:
+        return 4 * x * x * x
+    return 1 - ((-2 * x + 2) ** 3) / 2
+
+
+def ease_out_quad(x):
+    return 1 - (1 - x) * (1 - x)
+
+
+EASINGS = {
+    'linear': ease_linear,
+    'easeInOutSine': ease_in_out_sine,
+    'easeInOutQuad': ease_in_out_quad,
+    'easeInOutCubic': ease_in_out_cubic,
+    'easeOutQuad': ease_out_quad,
+}
+
+
+def get_easing(name):
+    if name is None or name == '':
+        name = DEFAULT_EASING
+
+    if name in EASINGS:
+        return EASINGS[name]
+
+    return EASINGS[DEFAULT_EASING]
+
+
+# ============================================================
+# JOINT CLASS
+# ============================================================
+
+class Joint:
+    """
+    Logical master-side joint.
+
+    Supports one or more physical motors.
+
+    Coordinate convention:
+        motor_angle = joint_angle * gear_ratio
+    """
+
+    def __init__(self, name, motors, signs, gear_ratio, joint_limits, stop_mode):
+        self.name = name
+        self.motors = motors
+        self.signs = signs
+        self.gear_ratio = gear_ratio
+        self.joint_limits = joint_limits
+        self.stop_mode_value = stop_mode
+
+    def motor_angle(self):
+        total = 0
+        count = len(self.motors)
+
+        for i in range(count):
+            total += self.motors[i].angle() * self.signs[i]
+
+        return total / count
+
+    def joint_angle(self):
+        return self.motor_angle() / self.gear_ratio
+
+    def joint_to_motor(self, joint_angle):
+        return joint_angle * self.gear_ratio
+
+    def motor_to_joint(self, motor_angle):
+        return motor_angle / self.gear_ratio
+
+    def reset_joint_angle(self, joint_angle):
+        motor_angle = self.joint_to_motor(joint_angle)
+
+        for i in range(len(self.motors)):
+            self.motors[i].reset_angle(motor_angle * self.signs[i])
+
+    def check_joint_limit(self, joint_target):
+        if self.joint_limits is None:
+            return
+
+        min_angle = self.joint_limits[0]
+        max_angle = self.joint_limits[1]
+
+        if joint_target < min_angle or joint_target > max_angle:
+            raise ValueError(
+                '{} target {} outside limits {}..{}'.format(
+                    self.name, joint_target, min_angle, max_angle
+                )
+            )
+
+    def physical_target(self, logical_motor_target, motor_index):
+        return int(logical_motor_target * self.signs[motor_index])
+
+    def track_motor_target(self, logical_motor_target):
+        joint_target = self.motor_to_joint(logical_motor_target)
+        self.check_joint_limit(joint_target)
+
+        for i in range(len(self.motors)):
+            self.motors[i].track_target(
+                self.physical_target(logical_motor_target, i)
+            )
+
+    def apply_stop(self):
+        for motor in self.motors:
+            if self.stop_mode_value == Stop.HOLD:
+                motor.hold()
+            elif self.stop_mode_value == Stop.COAST:
+                motor.stop()
+            else:
+                motor.brake()
+
+
+# ============================================================
+# MASTER JOINTS
+# ============================================================
+
+base = Joint(
+    'base',
+    [base_motor],
+    [1],
+    GEAR_RATIOS['base'],
+    JOINT_LIMITS['base'],
+    STOP_MODE_BY_JOINT['base']
+)
+
+shoulder = Joint(
+    'shoulder',
+    [shoulder_left_motor, shoulder_right_motor],
+    SHOULDER_SIGNS,
+    GEAR_RATIOS['shoulder'],
+    JOINT_LIMITS['shoulder'],
+    STOP_MODE_BY_JOINT['shoulder']
+)
+
+elbow = Joint(
+    'elbow',
+    [elbow_motor],
+    [1],
+    GEAR_RATIOS['elbow'],
+    JOINT_LIMITS['elbow'],
+    STOP_MODE_BY_JOINT['elbow']
+)
+
+JOINTS = {
+    'base': base,
+    'shoulder': shoulder,
+    'elbow': elbow,
+}
+
+JOINT_ORDER = ['base', 'shoulder', 'elbow']
+
+
+# ============================================================
+# COMMAND HELPERS
+# ============================================================
+
+def ABS_J(joint, angle):
+    return {
+        'joint': joint,
+        'unit': 'joint',
+        'mode': 'abs',
+        'value': angle
+    }
+
+
+def REL_J(joint, delta):
+    return {
+        'joint': joint,
+        'unit': 'joint',
+        'mode': 'rel',
+        'value': delta
+    }
+
+
+def ABS_M(joint, angle):
+    return {
+        'joint': joint,
+        'unit': 'motor',
+        'mode': 'abs',
+        'value': angle
+    }
+
+
+def REL_M(joint, delta):
+    return {
+        'joint': joint,
+        'unit': 'motor',
+        'mode': 'rel',
+        'value': delta
+    }
+
+
+def STEP(label, master_cmds, slave_cmds, duration_ms, easing='linear', pause_ms=1000):
+    return {
+        'label': label,
+        'master_cmds': master_cmds,
+        'slave_cmds': slave_cmds,
+        'duration_ms': duration_ms,
+        'easing': easing,
+        'pause_ms': pause_ms
+    }
+
+
+# ============================================================
+# LOCAL MASTER PLANNING
+# ============================================================
+
+def validate_parallel(commands):
+    seen = []
+
+    for cmd in commands:
+        name = cmd['joint']
+
+        if name in seen:
+            raise ValueError('Joint repeated in one parallel group: {}'.format(name))
+
+        seen.append(name)
+
+
+def plan_master_commands(commands):
+    validate_parallel(commands)
+
+    plans = []
+
+    for cmd in commands:
+        joint = JOINTS[cmd['joint']]
+        unit = cmd['unit']
+        mode = cmd['mode']
+        value = cmd['value']
+
+        start_motor = joint.motor_angle()
+        start_joint = joint.joint_angle()
+
+        if mode == 'abs':
+            if unit == 'motor':
+                target_motor = value
+                target_joint = joint.motor_to_joint(target_motor)
+            elif unit == 'joint':
+                target_joint = value
+                target_motor = joint.joint_to_motor(target_joint)
+            else:
+                raise ValueError('Unknown unit: {}'.format(unit))
+
+        elif mode == 'rel':
+            if unit == 'motor':
+                target_motor = start_motor + value
+                target_joint = joint.motor_to_joint(target_motor)
+            elif unit == 'joint':
+                target_joint = start_joint + value
+                target_motor = joint.joint_to_motor(target_joint)
+            else:
+                raise ValueError('Unknown unit: {}'.format(unit))
+
+        else:
+            raise ValueError('Unknown mode: {}'.format(mode))
+
+        joint.check_joint_limit(target_joint)
+
+        delta_motor = target_motor - start_motor
+        skip = abs_value(delta_motor) <= DEADBAND_MOTOR_DEG
+
+        plans.append({
+            'joint': joint,
+            'start_motor': start_motor,
+            'target_motor': target_motor,
+            'delta_motor': delta_motor,
+            'last_sent': None,
+            'skip': skip
+        })
+
+    return plans
+
+
+def maybe_track(plan, target, force):
+    joint = plan['joint']
+    last = plan['last_sent']
+
+    if force or last is None:
+        joint.track_motor_target(target)
+        plan['last_sent'] = target
+        return
+
+    if abs_value(target - last) >= TRACK_TARGET_MIN_UPDATE_MOTOR_DEG:
+        joint.track_motor_target(target)
+        plan['last_sent'] = target
+
+
+def execute_master_plan_timed(plans, duration_ms, easing_name):
+    if duration_ms <= 0:
+        return True
+
+    easing = get_easing(easing_name)
+    active = []
+
+    for plan in plans:
+        if not plan['skip']:
+            active.append(plan)
+
+    if len(active) == 0:
+        return True
+
+    timer = StopWatch()
+
+    while timer.time() < duration_ms:
+        ratio = timer.time() / duration_ms
+        ratio = clamp(ratio, 0, 1)
+
+        eased = easing(ratio)
+
+        if CLAMP_EASING_OUTPUT:
+            eased = clamp(eased, 0, 1)
+
+        for plan in active:
+            target = plan['start_motor'] + plan['delta_motor'] * eased
+            maybe_track(plan, target, False)
+
+        wait(PROFILE_UPDATE_MS)
+
+    for plan in active:
+        maybe_track(plan, plan['target_motor'], True)
+
+    for plan in active:
+        plan['joint'].apply_stop()
+
+    return True
+
+
+def reset_master_as_zero():
+    for name in JOINT_ORDER:
+        JOINTS[name].reset_joint_angle(0)
+
+
+def print_master_states(prefix):
+    print(prefix)
+
+    for name in JOINT_ORDER:
+        joint = JOINTS[name]
+        print(
+            '{}: motor={} joint={}'.format(
+                name, joint.motor_angle(), joint.joint_angle()
+            )
+        )
+
+
+# ============================================================
+# SLAVE MESSAGE ENCODING
+# ============================================================
+
+def encode_slave_commands(commands):
+    if len(commands) == 0:
+        return 'NONE'
+
+    parts = []
+
+    for cmd in commands:
+        parts.append(
+            '{},{},{},{}'.format(
+                cmd['joint'],
+                cmd['unit'],
+                cmd['mode'],
+                cmd['value']
+            )
+        )
+
+    return ';'.join(parts)
+
+
+def send_slave_prepare(step_id, duration_ms, easing, slave_cmds):
+    payload = encode_slave_commands(slave_cmds)
+
+    msg = 'PREP|{}|{}|{}|{}'.format(
+        step_id,
+        duration_ms,
+        easing,
+        payload
+    )
+
+    print('MASTER TX: {}'.format(msg))
+    cmd_box.send(msg)
+
+    status_box.wait()
+    reply = status_box.read()
+
+    print('MASTER RX: {}'.format(reply))
+
+    expected = 'READY|{}'.format(step_id)
+
+    if reply != expected:
+        ev3.screen.clear()
+        ev3.screen.print('SLAVE PREP ERR')
+        ev3.screen.print(reply[:16])
+        ev3.screen.print(reply[16:32])
+        raise RuntimeError('Unexpected slave reply: {}'.format(reply))
+
+
+def send_slave_go(step_id):
+    msg = 'GO|{}'.format(step_id)
+    print('MASTER TX: {}'.format(msg))
+    cmd_box.send(msg)
+
+
+def wait_slave_done(step_id):
+    status_box.wait()
+    reply = status_box.read()
+
+    print('MASTER RX: {}'.format(reply))
+
+    expected = 'DONE|{}'.format(step_id)
+
+    if reply != expected:
+        ev3.screen.clear()
+        ev3.screen.print('SLAVE RUN ERR')
+        ev3.screen.print(reply[:16])
+        ev3.screen.print(reply[16:32])
+        raise RuntimeError('Unexpected slave completion reply: {}'.format(reply))
+
+
+# ============================================================
+# COORDINATED STEP EXECUTION
+# ============================================================
+
+def run_coordinated_step(step_id, step):
+    label = step['label']
+    master_cmds = step['master_cmds']
+    slave_cmds = step['slave_cmds']
+    duration_ms = step['duration_ms']
+    easing = step['easing']
+    pause_ms = step['pause_ms']
+
+    ev3.screen.clear()
+    ev3.screen.print('STEP {}'.format(step_id))
+    ev3.screen.print(label)
+
+    print('')
+    print('=' * 70)
+    print('COORDINATED STEP {}: {}'.format(step_id, label))
+    print('=' * 70)
+
+    master_plans = plan_master_commands(master_cmds)
+
+    # Prepare slave before movement.
+    if len(slave_cmds) > 0:
+        send_slave_prepare(step_id, duration_ms, easing, slave_cmds)
+
+    # Start marker.
+    beep_start_marker()
+
+    # Send GO to slave, then start local motion.
+    if len(slave_cmds) > 0:
+        send_slave_go(step_id)
+
+    if MASTER_START_DELAY_AFTER_GO_MS > 0:
+        wait(MASTER_START_DELAY_AFTER_GO_MS)
+
+    execute_master_plan_timed(master_plans, duration_ms, easing)
+
+    # Wait for slave completion.
+    if len(slave_cmds) > 0:
+        wait_slave_done(step_id)
+
+    print_master_states('MASTER after step:')
+
+    beep_ok()
+
+    if pause_ms > 0:
+        wait(pause_ms)
+
+
+# ============================================================
+# TEST SCENARIO INVOLVING BOTH BRICKS
+# ============================================================
+#
+# Master joints:
+#   base, shoulder, elbow
+#
+# Slave joints:
+#   elbow_rotate, wrist_flexion_extension, wrist_pronation_supination, gripper
+#
+# Rename slave joints after you define their real mechanical meaning.
+
+SCENARIO = [
+
+    STEP(
+        'Test one slave joint only',
+        master_cmds=[
+            ABS_J('base', 0),
+        ],
+        slave_cmds=[
+            ABS_J('elbow_rotate', 0),
+        ],
+        duration_ms=1000,
+        easing='linear',
+        pause_ms=1000
+    ),
+
+
+    STEP(
+        'All joints zero',
+        master_cmds=[
+            ABS_J('base', 0),
+            ABS_J('shoulder', 0),
+            ABS_J('elbow', 0),
+        ],
+        slave_cmds=[
+            ABS_J('elbow_rotate', 0),
+            ABS_J('wrist_flexion_extension', 0),
+            ABS_J('wrist_pronation_supination', 0),
+            ABS_J('gripper', 0),
+        ],
+        duration_ms=3000,
+        easing='linear',
+        pause_ms=1000
+    ),
+
+    STEP(
+        'Base + elbow_rotate synchronized',
+        master_cmds=[
+            ABS_J('base', 15),
+        ],
+        slave_cmds=[
+            ABS_J('elbow_rotate', 15),
+        ],
+        duration_ms=3000,
+        easing='easeInOutSine',
+        pause_ms=1000
+    ),
+
+    STEP(
+        'Shoulder + elbow + two slave joints',
+        master_cmds=[
+            ABS_J('shoulder', 8),
+            ABS_J('elbow', 12),
+        ],
+        slave_cmds=[
+            ABS_J('wrist_flexion_extension', 10),
+            ABS_J('wrist_pronation_supination', -10),
+        ],
+        duration_ms=4000,
+        easing='easeInOutQuad',
+        pause_ms=1000
+    ),
+
+    STEP(
+        'All master and slave joints small negative pose',
+        master_cmds=[
+            ABS_J('base', -12),
+            ABS_J('shoulder', -8),
+            ABS_J('elbow', -12),
+        ],
+        slave_cmds=[
+            ABS_J('elbow_rotate', -10),
+            ABS_J('wrist_flexion_extension', -10),
+            ABS_J('wrist_pronation_supination', 10),
+            ABS_J('gripper', 5),
+        ],
+        duration_ms=4000,
+        easing='easeInOutCubic',
+        pause_ms=1000
+    ),
+
+    STEP(
+        'Relative coordinated movement',
+        master_cmds=[
+            REL_J('base', 10),
+            REL_J('elbow', 8),
+        ],
+        slave_cmds=[
+            REL_J('elbow_rotate', 8),
+            REL_J('gripper', -5),
+        ],
+        duration_ms=3000,
+        easing='easeOutQuad',
+        pause_ms=1000
+    ),
+
+    STEP(
+        'Return all joints to zero',
+        master_cmds=[
+            ABS_J('base', 0),
+            ABS_J('shoulder', 0),
+            ABS_J('elbow', 0),
+        ],
+        slave_cmds=[
+            ABS_J('elbow_rotate', 0),
+            ABS_J('wrist_flexion_extension', 0),
+            ABS_J('wrist_pronation_supination', 0),
+            ABS_J('gripper', 0),
+        ],
+        duration_ms=4000,
+        easing='easeInOutSine',
+        pause_ms=1000
+    ),
+]
+
+
+# ============================================================
+# MAIN PROGRAM
+# ============================================================
+
+ev3.screen.clear()
+ev3.screen.print('MASTER')
+ev3.screen.print('Connecting')
+
+print('MASTER: connecting to slave {}'.format(SLAVE_BRICK_NAME))
+client.connect(SLAVE_BRICK_NAME)
+print('MASTER: connected')
+
+ev3.screen.clear()
+ev3.screen.print('MASTER')
+ev3.screen.print('Connected')
+
+reset_master_as_zero()
+print_master_states('MASTER initial zero:')
+
+try:
+    for i in range(len(SCENARIO)):
+        run_coordinated_step(i, SCENARIO[i])
+
+except Exception as e:
+    print('MASTER ERROR: {}'.format(e))
+    beep_error()
+    cmd_box.send('STOP')
+
+ev3.screen.clear()
+ev3.screen.print('MASTER')
+ev3.screen.print('DONE')
+
+print('MASTER: scenario complete')
+beep_ok()

ev3-robotic-arm-master/robotarmmovement/tests/test01_slave.py

@@ -0,0 +1,629 @@
+#!/usr/bin/env pybricks-micropython
+
+from math import sin, cos, pi
+
+from pybricks.hubs import EV3Brick
+from pybricks.ev3devices import Motor
+from pybricks.parameters import Port, Stop
+from pybricks.tools import wait, StopWatch
+from pybricks.messaging import BluetoothMailboxServer, TextMailbox
+
+
+# ============================================================
+# SLAVE BRICK PROGRAM
+# ============================================================
+#
+# Run this program FIRST.
+#
+# The slave:
+#   1. waits for master Bluetooth connection,
+#   2. waits for PREP command,
+#   3. prepares local motion plan,
+#   4. replies READY,
+#   5. waits for GO,
+#   6. executes local slave joints,
+#   7. replies DONE.
+#
+# Message format:
+#   PREP|step_id|duration_ms|easing|joint,unit,mode,value;joint,unit,mode,value
+#   GO|step_id
+#   STOP
+#
+# Example payload:
+#   PREP|3|3000|easeInOutSine|elbow_rotate,joint,abs,10;wrist_flexion_extension,joint,abs,-5
+
+
+# ============================================================
+# GENERAL SETTINGS
+# ============================================================
+
+DEFAULT_SPEED = 200
+PROFILE_UPDATE_MS = 20
+POLL_MS = 10
+
+DEFAULT_EASING = 'linear'
+CLAMP_EASING_OUTPUT = True
+
+STOP_MODE_DEFAULT = Stop.BRAKE
+
+DEADBAND_MOTOR_DEG = 1.5
+TRACK_TARGET_MIN_UPDATE_MOTOR_DEG = 1.0
+
+SOUND_ENABLED = True
+
+
+# ============================================================
+# SLAVE JOINT CONFIGURATION
+# ============================================================
+#
+# Replace names, gear ratios, signs, and limits with your real second-brick axes.
+#
+# ports:
+#   list of physical motor ports. Usually one port.
+#
+# signs:
+#   list of signs matching ports. Use -1 if motor direction is opposite.
+#
+# gear_ratio:
+#   motor_angle = joint_angle * gear_ratio
+#
+# joint_limits:
+#   None or (min_angle, max_angle), in JOINT degrees.
+
+SLAVE_JOINT_CONFIGS = [
+    {
+        'name': 'elbow_rotate',
+        'ports': [Port.A],
+        'signs': [1],
+        'gear_ratio': 7.5,
+        'joint_limits': None,
+        'stop_mode': Stop.BRAKE,
+    },
+    {
+        'name': 'wrist_flexion_extension',
+        'ports': [Port.B],
+        'signs': [1],
+        'gear_ratio': 5.0,
+        'joint_limits': None,
+        'stop_mode': Stop.BRAKE,
+    },
+    {
+        'name': 'wrist_pronation_supination',
+        'ports': [Port.C],
+        'signs': [1],
+        'gear_ratio': 7.5,
+        'joint_limits': None,
+        'stop_mode': Stop.BRAKE,
+    },
+    {
+        'name': 'gripper',
+        'ports': [Port.D],
+        'signs': [1],
+        'gear_ratio': 1.0,
+        'joint_limits': None,
+        'stop_mode': Stop.BRAKE,
+    },
+]
+
+
+# ============================================================
+# HARDWARE / BLUETOOTH
+# ============================================================
+
+ev3 = EV3Brick()
+
+server = BluetoothMailboxServer()
+cmd_box = TextMailbox('command', server)
+status_box = TextMailbox('status', server)
+
+
+# ============================================================
+# UTILITIES
+# ============================================================
+
+def clamp(value, min_value, max_value):
+    if value < min_value:
+        return min_value
+    if value > max_value:
+        return max_value
+    return value
+
+
+def abs_value(value):
+    if value < 0:
+        return -value
+    return value
+
+
+def beep_ok():
+    if SOUND_ENABLED:
+        ev3.speaker.beep(frequency=1000, duration=80)
+
+
+def beep_error():
+    if SOUND_ENABLED:
+        ev3.speaker.beep(frequency=220, duration=200)
+        wait(80)
+        ev3.speaker.beep(frequency=220, duration=200)
+
+
+# ============================================================
+# EASING FUNCTIONS
+# ============================================================
+
+def ease_linear(x):
+    return x
+
+
+def ease_in_out_sine(x):
+    return -(cos(pi * x) - 1) / 2
+
+
+def ease_in_out_quad(x):
+    if x < 0.5:
+        return 2 * x * x
+    return 1 - ((-2 * x + 2) ** 2) / 2
+
+
+def ease_in_out_cubic(x):
+    if x < 0.5:
+        return 4 * x * x * x
+    return 1 - ((-2 * x + 2) ** 3) / 2
+
+
+def ease_out_quad(x):
+    return 1 - (1 - x) * (1 - x)
+
+
+EASINGS = {
+    'linear': ease_linear,
+    'easeInOutSine': ease_in_out_sine,
+    'easeInOutQuad': ease_in_out_quad,
+    'easeInOutCubic': ease_in_out_cubic,
+    'easeOutQuad': ease_out_quad,
+}
+
+
+def get_easing(name):
+    if name is None or name == '':
+        name = DEFAULT_EASING
+
+    if name in EASINGS:
+        return EASINGS[name]
+
+    return EASINGS[DEFAULT_EASING]
+
+
+# ============================================================
+# JOINT CLASS
+# ============================================================
+
+class Joint:
+    """
+    Logical robot-arm joint.
+
+    Supports one or more physical motors.
+
+    Coordinate convention:
+        motor_angle = joint_angle * gear_ratio
+
+    For multiple motors:
+        logical motor angle is the signed average of all motor encoders.
+    """
+
+    def __init__(self, name, motors, signs, gear_ratio, joint_limits, stop_mode):
+        self.name = name
+        self.motors = motors
+        self.signs = signs
+        self.gear_ratio = gear_ratio
+        self.joint_limits = joint_limits
+        self.stop_mode_value = stop_mode
+
+    def motor_angle(self):
+        total = 0
+        count = len(self.motors)
+
+        for i in range(count):
+            total += self.motors[i].angle() * self.signs[i]
+
+        return total / count
+
+    def joint_angle(self):
+        return self.motor_angle() / self.gear_ratio
+
+    def joint_to_motor(self, joint_angle):
+        return joint_angle * self.gear_ratio
+
+    def motor_to_joint(self, motor_angle):
+        return motor_angle / self.gear_ratio
+
+    def reset_joint_angle(self, joint_angle):
+        motor_angle = self.joint_to_motor(joint_angle)
+
+        for i in range(len(self.motors)):
+            self.motors[i].reset_angle(motor_angle * self.signs[i])
+
+    def check_joint_limit(self, joint_target):
+        if self.joint_limits is None:
+            return
+
+        min_angle = self.joint_limits[0]
+        max_angle = self.joint_limits[1]
+
+        if joint_target < min_angle or joint_target > max_angle:
+            raise ValueError(
+                '{} target {} outside limits {}..{}'.format(
+                    self.name, joint_target, min_angle, max_angle
+                )
+            )
+
+    def physical_target(self, logical_motor_target, motor_index):
+        return int(logical_motor_target * self.signs[motor_index])
+
+    def run_motor_target(self, logical_motor_target, speed):
+        joint_target = self.motor_to_joint(logical_motor_target)
+        self.check_joint_limit(joint_target)
+
+        for i in range(len(self.motors)):
+            self.motors[i].run_target(
+                speed,
+                self.physical_target(logical_motor_target, i),
+                then=self.stop_mode_value,
+                wait=False
+            )
+
+    def track_motor_target(self, logical_motor_target):
+        joint_target = self.motor_to_joint(logical_motor_target)
+        self.check_joint_limit(joint_target)
+
+        for i in range(len(self.motors)):
+            self.motors[i].track_target(
+                self.physical_target(logical_motor_target, i)
+            )
+
+    def apply_stop(self):
+        for motor in self.motors:
+            if self.stop_mode_value == Stop.HOLD:
+                motor.hold()
+            elif self.stop_mode_value == Stop.COAST:
+                motor.stop()
+            else:
+                motor.brake()
+
+    def all_motors(self):
+        return self.motors
+
+
+# ============================================================
+# JOINT CREATION
+# ============================================================
+
+JOINTS = {}
+JOINT_ORDER = []
+
+
+def create_joints():
+    for cfg in SLAVE_JOINT_CONFIGS:
+        motors = []
+
+        for port in cfg['ports']:
+            motors.append(Motor(port))
+
+        joint = Joint(
+            cfg['name'],
+            motors,
+            cfg['signs'],
+            cfg['gear_ratio'],
+            cfg['joint_limits'],
+            cfg['stop_mode']
+        )
+
+        JOINTS[cfg['name']] = joint
+        JOINT_ORDER.append(cfg['name'])
+
+
+def reset_all_as_zero():
+    for name in JOINT_ORDER:
+        JOINTS[name].reset_joint_angle(0)
+
+
+def stop_all():
+    for name in JOINT_ORDER:
+        JOINTS[name].apply_stop()
+
+
+# ============================================================
+# COMMAND PARSING / PLANNING
+# ============================================================
+
+def parse_command_payload(payload):
+    """
+    Parses:
+        joint,unit,mode,value;joint,unit,mode,value
+
+    Example:
+        elbow_rotate,joint,abs,10;wrist_flexion_extension,joint,rel,-5
+    """
+    commands = []
+
+    if payload == '' or payload == 'NONE':
+        return commands
+
+    items = payload.split(';')
+
+    for item in items:
+        parts = item.split(',')
+
+        if len(parts) != 4:
+            raise ValueError('Invalid command item: {}'.format(item))
+
+        commands.append({
+            'joint': parts[0],
+            'unit': parts[1],
+            'mode': parts[2],
+            'value': float(parts[3])
+        })
+
+    return commands
+
+
+def validate_parallel(commands):
+    seen = []
+
+    for cmd in commands:
+        joint_name = cmd['joint']
+
+        if joint_name in seen:
+            raise ValueError('Joint repeated in one parallel group: {}'.format(joint_name))
+
+        seen.append(joint_name)
+
+
+def plan_commands(commands):
+    validate_parallel(commands)
+
+    plans = []
+
+    for cmd in commands:
+        joint = JOINTS[cmd['joint']]
+        unit = cmd['unit']
+        mode = cmd['mode']
+        value = cmd['value']
+
+        start_motor = joint.motor_angle()
+        start_joint = joint.joint_angle()
+
+        if mode == 'abs':
+            if unit == 'motor':
+                target_motor = value
+                target_joint = joint.motor_to_joint(target_motor)
+            elif unit == 'joint':
+                target_joint = value
+                target_motor = joint.joint_to_motor(target_joint)
+            else:
+                raise ValueError('Unknown unit: {}'.format(unit))
+
+        elif mode == 'rel':
+            if unit == 'motor':
+                target_motor = start_motor + value
+                target_joint = joint.motor_to_joint(target_motor)
+            elif unit == 'joint':
+                target_joint = start_joint + value
+                target_motor = joint.joint_to_motor(target_joint)
+            else:
+                raise ValueError('Unknown unit: {}'.format(unit))
+
+        else:
+            raise ValueError('Unknown mode: {}'.format(mode))
+
+        joint.check_joint_limit(target_joint)
+
+        delta_motor = target_motor - start_motor
+        skip = abs_value(delta_motor) <= DEADBAND_MOTOR_DEG
+
+        plans.append({
+            'joint': joint,
+            'start_motor': start_motor,
+            'target_motor': target_motor,
+            'delta_motor': delta_motor,
+            'last_sent': None,
+            'skip': skip
+        })
+
+    return plans
+
+
+# ============================================================
+# MOVEMENT EXECUTION
+# ============================================================
+
+def maybe_track(plan, target, force):
+    joint = plan['joint']
+    last = plan['last_sent']
+
+    if force or last is None:
+        joint.track_motor_target(target)
+        plan['last_sent'] = target
+        return
+
+    if abs_value(target - last) >= TRACK_TARGET_MIN_UPDATE_MOTOR_DEG:
+        joint.track_motor_target(target)
+        plan['last_sent'] = target
+
+
+def execute_plan_timed(plans, duration_ms, easing_name):
+    if duration_ms <= 0:
+        return True
+
+    easing = get_easing(easing_name)
+    active = []
+
+    for plan in plans:
+        if not plan['skip']:
+            active.append(plan)
+
+    if len(active) == 0:
+        return True
+
+    timer = StopWatch()
+
+    while timer.time() < duration_ms:
+        ratio = timer.time() / duration_ms
+        ratio = clamp(ratio, 0, 1)
+
+        eased = easing(ratio)
+
+        if CLAMP_EASING_OUTPUT:
+            eased = clamp(eased, 0, 1)
+
+        for plan in active:
+            target = plan['start_motor'] + plan['delta_motor'] * eased
+            maybe_track(plan, target, False)
+
+        wait(PROFILE_UPDATE_MS)
+
+    for plan in active:
+        maybe_track(plan, plan['target_motor'], True)
+
+    for plan in active:
+        plan['joint'].apply_stop()
+
+    return True
+
+
+# ============================================================
+# STATUS / DISPLAY
+# ============================================================
+
+def print_states(prefix):
+    print(prefix)
+
+    for name in JOINT_ORDER:
+        joint = JOINTS[name]
+        print(
+            '{}: motor={} joint={}'.format(
+                name, joint.motor_angle(), joint.joint_angle()
+            )
+        )
+
+
+# ============================================================
+# MAIN LOOP
+# ============================================================
+
+create_joints()
+
+ev3.screen.clear()
+ev3.screen.print('SLAVE')
+ev3.screen.print('Waiting BT')
+
+print('SLAVE: waiting for Bluetooth connection...')
+server.wait_for_connection()
+print('SLAVE: connected')
+
+ev3.screen.clear()
+ev3.screen.print('SLAVE')
+ev3.screen.print('Connected')
+
+reset_all_as_zero()
+print_states('SLAVE initial zero:')
+
+prepared_step_id = None
+prepared_duration = 0
+prepared_easing = DEFAULT_EASING
+prepared_plans = []
+
+while True:
+    cmd_box.wait()
+    message = cmd_box.read()
+
+    print('SLAVE RX: {}'.format(message))
+
+    try:
+        parts = message.split('|')
+        command_type = parts[0]
+
+        print('SLAVE MSG PARTS COUNT: {}'.format(len(parts)))
+
+        if command_type == 'STOP':
+            stop_all()
+            status_box.send('STOPPED')
+            beep_error()
+
+        elif command_type == 'PREP':
+            if len(parts) < 5:
+                raise ValueError('Bad PREP parts: {}'.format(len(parts)))
+            
+            prepared_step_id = parts[1]
+            prepared_duration = int(parts[2])
+            prepared_easing = parts[3]
+            payload = parts[4]
+
+            commands = parse_command_payload(payload)
+            prepared_plans = plan_commands(commands)
+
+            ev3.screen.clear()
+            ev3.screen.print('SLAVE PREP')
+            ev3.screen.print(prepared_step_id)
+
+            status_box.send('READY|{}'.format(prepared_step_id))
+            beep_ok()
+
+        elif command_type == 'GO':
+            step_id = parts[1]
+
+            if step_id != prepared_step_id:
+                status_box.send('ERR|{}|not_prepared'.format(step_id))
+                beep_error()
+            else:
+                ev3.screen.clear()
+                ev3.screen.print('SLAVE GO')
+                ev3.screen.print(step_id)
+
+                ok = execute_plan_timed(
+                    prepared_plans,
+                    prepared_duration,
+                    prepared_easing
+                )
+
+                if ok:
+                    status_box.send('DONE|{}'.format(step_id))
+                    beep_ok()
+                else:
+                    status_box.send('ERR|{}|movement_failed'.format(step_id))
+                    beep_error()
+
+        elif command_type == 'QUIT':
+            stop_all()
+            status_box.send('BYE')
+            break
+
+        else:
+            status_box.send('ERR|unknown_command')
+            beep_error()
+
+    except Exception as e:
+        stop_all()
+
+        err = str(e)
+
+        ev3.screen.clear()
+        ev3.screen.print('SLAVE ERROR')
+        ev3.screen.print(err[:16])
+        ev3.screen.print(err[16:32])
+
+        print('SLAVE ERROR: {}'.format(err))
+
+        # Send actual error back to master.
+        # Keep it short because TextMailbox messages should not be too long.
+        status_box.send('ERR|{}|{}'.format(
+            prepared_step_id if prepared_step_id is not None else 'none',
+            err[:40]
+        ))
+
+        beep_error()
+
+stop_all()
+ev3.screen.clear()
+ev3.screen.print('SLAVE END')
+print('SLAVE: program ended')