State Reading

Full State Snapshot

Read the complete arm state in one call, including TCP pose plus angle, velocity, acceleration, torque, and temperature for all joints.

from realhand import A7

with A7(side="left", interface_name="can0") as arm:
    arm.enable()
    state = arm.get_state()
    print(state.pose)
    print(f"Actual angle of the first joint: {state.joint_angles[0].angle:.4f} rad")

Return value

State: Contains pose, joint_angles, joint_control_angles, joint_velocities, joint_control_velocities, joint_control_acceleration, joint_torques, and joint_temperatures

`State` data model

Field	Description
`pose`	TCP pose (`Pose`)
`joint_angles`	Actual angles of the 7 joints (`list[AngleState]`)
`joint_control_angles`	Control angles of the 7 joints (`list[AngleState]`)
`joint_velocities`	Actual velocities of the 7 joints (`list[VelocityState]`)
`joint_control_velocities`	Control velocities of the 7 joints (`list[VelocityState]`)
`joint_control_acceleration`	Control accelerations of the 7 joints (`list[AccelerationState]`)
`joint_torques`	Actual torques of the 7 joints (`list[TorqueState]`)
`joint_temperatures`	Temperatures of the 7 joints (`list[TemperatureState]`)

Each sub-state model includes a value field and a timestamp (Unix time in seconds).

Sub-state model fields

Model	Value field	Timestamp field
`AngleState`	`.angle`	`.timestamp`
`VelocityState`	`.velocity`	`.timestamp`
`AccelerationState`	`.acceleration`	`.timestamp`
`TorqueState`	`.torque`	`.timestamp`
`TemperatureState`	`.temperature`	`.timestamp`

Read Individual State Items

Besides get_state(), the following methods return a single kind of state. All of them return lists for 7 joints, except get_pose().

from realhand import A7

with A7(side="left", interface_name="can0") as arm:
    arm.enable()
    angles = arm.get_angles()
    velocities = arm.get_velocities()
    temps = arm.get_temperatures()
    pose = arm.get_pose()
    print(f"Actual angle of the second joint: {angles[1]:.4f} rad")
    print(f"Actual velocity of the third joint: {velocities[2]:.4f} rad/s")
    print(f"Actual temperature of the fourth joint: {temps[3]:.1f} °C")
    print(f"TCP: ({pose.x:.3f}m, {pose.y:.3f}m, {pose.z:.3f}m)")

Return values

Method	Return value	Unit
`get_angles()`	Actual angles of 7 joints	rad
`get_control_angles()`	Control angles of 7 joints	rad
`get_velocities()`	Actual velocities of 7 joints	rad/s
`get_control_velocities()`	Control velocities of 7 joints	rad/s
`get_control_acceleration()`	Control accelerations of 7 joints	rad/s²
`get_torques()`	Actual torques of 7 joints	Nm
`get_temperatures()`	Temperatures of 7 joints	°C
`get_pose()`	TCP pose	m, rad

Sensor Data

A7 uses polling to collect sensor data. get_*() returns the value from the latest polling cycle.

Data type	Unit	Default polling interval	Maximum delay
Angle	rad	10 ms	≈ 10 ms
Velocity	rad/s	10 ms	≈ 10 ms
Torque	Nm	50 ms	≈ 50 ms
Temperature	°C	1000 ms	≈ 1000 ms

If you need lower latency, use start_polling() to configure different intervals for different sensor types:

from realhand import A7
from realhand.arm.a7 import SensorType

with A7(side="left", interface_name="can0") as arm:
    arm.start_polling(
        {
            SensorType.POSITION: 0.005,  # 5 ms = 200 Hz
            SensorType.VELOCITY: 0.005,
            SensorType.TORQUE: 0.1,
            SensorType.TEMPERATURE: 2.0,
        }
    )
    arm.enable()
    arm.home()

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