Power Sensor Component

A power sensor is a device that reports measurements of the voltage, current, and power consumption in your machine’s system. Integrate this component to monitor your power levels.

Supported models

To use your power sensor with Viam, check whether one of the following built-in models or modular resources supports your power sensor.

Built-in models

For configuration information, click on the model name:

ModelDescription
fakea digital power sensor for testing
ina219INA219 power sensor; current and power monitor
ina226INA226 power sensor; current and power monitor
renogysolar charge controller

Modular resources

Search for additional power_sensor models that you can add from the Viam Registry:

For configuration information, click on the model name:

Model
Description

Control your power sensor with Viam’s client SDK libraries

To get started using Viam’s SDKs to connect to and control your machine, go to your machine’s page on the Viam app, navigate to the CONNECT tab’s Code sample page, select your preferred programming language, and copy the sample code generated.

When executed, this sample code will create a connection to your machine as a client. Once connected, you can control your machine programmatically by adding API method calls as shown in the following examples.

These examples assume you have a power sensor called "my_power_sensor" configured as a component of your machine. If your power sensor has a different name, change the name in the code.

Import the power sensor package for the SDK you are using:

from viam.components.power_sensor import PowerSensor
import (
  "go.viam.com/rdk/components/powersensor"
)

API

The power sensor component supports the following methods:

Method NameDescription
GetCurrentReturn the current of a specified device and whether it is AC or DC.
GetVoltageReturn the voltage of a specified device and whether it is AC or DC.
GetPowerReturn the power consumption of a specified device in watts.
GetGeometriesGet all the geometries associated with the power sensor in its current configuration, in the frame of the power sensor.
GetReadingsGet all measurements or readings that this power sensor provides.
DoCommandExecute model-specific commands that are not otherwise defined by the component API.
CloseSafely shut down the resource and prevent further use.

GetCurrent

Return the current of a specified device and whether it is AC or DC.

Parameters:

Returns:

  • (Tuple[float, bool]): A tuple which includes a float representing the current reading in amps, and a bool indicating whether the current is AC (true) or DC (false).

For more information, see the Python SDK Docs.

my_power_sensor = PowerSensor.from_robot(robot=robot, name='my_power_sensor')

# Get the current reading from the power sensor
current, is_ac = await my_power_sensor.get_current()
print("The current is ", current, " A, Is AC: ", is_ac)

Parameters:

Returns:

  • float64: The measurement of the current, represented as a 64-bit float number.
  • bool: Indicate whether current is AC (true) or DC (false).
  • error: Report any errors that might occur during operation. For a successful operation, error returns nil.

For more information, see the Go SDK Docs.

// Get the current reading from device in amps
current, isAC, err := myPowerSensor.Current(context.Background(), nil)

GetVoltage

Return the voltage reading of a specified device and whether it is AC or DC.

Parameters:

Returns:

  • (Tuple[float, bool]): A float representing the current reading in amps. A bool indicating whether the voltage is AC (true) or DC (false).

For more information, see the Python SDK Docs.

my_power_sensor = PowerSensor.from_robot(robot=robot, name='my_power_sensor')

# Get the voltage reading from the power sensor
voltage, is_ac = await my_power_sensor.get_voltage()
print("The voltage is", voltage, "V, Is AC:", is_ac)

Parameters:

Returns:

  • float64: The measurement of the voltage, represented as a 64-bit float number.
  • bool: Indicate whether voltage is AC (true) or DC (false).
  • error: Report any errors that might occur during operation. For a successful operation, error returns nil.

For more information, see the Go SDK Docs.

// Get the voltage from device in volts
voltage, isAC, err := myPowerSensor.Voltage(context.Background(), nil)

GetPower

Return the power reading in watts.

Parameters:

Returns:

  • float: The measurement of the power, represented as a float.

For more information, see the Python SDK Docs.

my_power_sensor = PowerSensor.from_robot(robot=robot, name='my_power_sensor')

# Get the power reading from the power sensor
power = await my_power_sensor.get_power()
print("The power is", power, "Watts")

Parameters:

Returns:

  • float64: The measurement of the power, represented as a 64-bit float number.
  • error: Report any errors that might occur during operation. For a successful operation, error returns nil.

For more information, see the Go SDK Docs.

// Get the power measurement from device in watts
power, err := myPowerSensor.Power(context.Background(), nil)

GetReadings

Get the measurements or readings that this power sensor provides. If a sensor is not configured to have a measurement or fails to read a piece of data, it will not appear in the readings dictionary.

Parameters:

  • extra (Optional[Dict[str, Any]]): Extra options to pass to the underlying RPC call.
  • timeout (Optional[float]): An option to set how long to wait (in seconds) before calling a time-out and closing the underlying RPC call.

Returns:

For more information, see the Python SDK Docs.

my_power_sensor = PowerSensor.from_robot(robot=robot, name='my_power_sensor')

# Get the readings provided by the sensor.
readings = await my_power_sensor.get_readings()

Parameters:

  • ctx (Context): A Context carries a deadline, a cancellation signal, and other values across API boundaries.
  • extra (map[string]interface{}): Extra options to pass to the underlying RPC call.

Returns:

  • (map[string]interface{}): The measurements or readings that this sensor provides.
  • (error): Report any errors that might occur during operation. For a successful operation, error returns nil.

For more information, see the Go SDK Docs.

// Get the readings provided by the sensor.
readings, err := myPowerSensor.Readings(context.Background(), nil)

GetGeometries

Get all the geometries associated with the power sensor in its current configuration, in the frame of the power sensor. The motion and navigation services use the relative position of inherent geometries to configured geometries representing obstacles for collision detection and obstacle avoidance while motion planning.

Parameters:

  • extra (Optional[Dict[str, Any]]): Extra options to pass to the underlying RPC call.
  • timeout (Optional[float]): An option to set how long to wait (in seconds) before calling a time-out and closing the underlying RPC call.

Returns:

  • (List[Geometry]): The geometries associated with the power sensor, in any order.

For more information, see the Python SDK Docs.

my_power_sensor = PowerSensor.from_robot(robot=robot, name="my_power_sensor")

geometries = await my_power_sensor.get_geometries()

if geometries:
    # Get the center of the first geometry
    print(f"Pose of the first geometry's centerpoint: {geometries[0].center}")

DoCommand

Execute model-specific commands that are not otherwise defined by the component API. If you are implementing your own power sensor and add features that have no built-in API method, you can access them with DoCommand.

Parameters:

Returns:

my_power_sensor = PowerSensor.from_robot(robot=robot, name="my_power_sensor")

reset_dict = {
  "command": "reset",
  "example_param": 30
}

do_response = await my_power_sensor.do_command(reset_dict)

For more information, see the Python SDK Docs.

Parameters:

Returns:

resp, err := myPowerSensor.DoCommand(context.Background(), map[string]interface{}{"command": "reset", "example_param": 30})

For more information, see the Go SDK Code.

Close

Safely shut down the resource and prevent further use.

Parameters:

  • None

Returns:

  • None
my_power_sensor = PowerSensor.from_robot(robot, "my_power_sensor")

await my_power_sensor.close()

For more information, see the Python SDK Docs.

Parameters:

  • ctx (Context): A Context carries a deadline, a cancellation signal, and other values across API boundaries.

Returns:

  • (error) : An error, if one occurred.
err := myPowerSensor.Close(context.Background())

For more information, see the Go SDK Docs.

Troubleshooting

You can find additional assistance in the Troubleshooting section.

You can also ask questions on the Viam Community Slack and we will be happy to help.