ForceSensor¶

The LEGO® Education SPIKE™ Prime Force Sensor (also known as the LEGO® Technic Force Sensor) can measure pressure of up to 10 newtons (N), but it can also be used as a touch sensor or a simple button.

class buildhat.ForceSensor(port, threshold_force=1)¶

Force sensor

Parameters: port – Port of device
Raises: DeviceError – Occurs if there is no force sensor attached to port

callback(func)¶

Set callback function

Parameters: func – Callback function

property connected¶

Whether device is connected or not

Returns: Connection status

static desc_for_id(typeid)¶

Translate integer type id to something more descriptive than the device name

Parameters: typeid – Type of device
Returns: Description of device

property description¶

Device on port info

Returns: Device description

deselect()¶: Unselect data from mode

get()¶

Extract information from device

Returns: Data from device
Raises: DeviceError – Occurs if device not in valid mode

get_force()¶

Return the force in (N)

Returns: The force exerted on the button
Return type: int

get_peak_force()¶

Get the maximum force registered since the sensor was reset

(The sensor gets reset when the firmware is reloaded)

Returns: 0 - 100
Return type: int

is_pressed()¶

Get whether the button is pressed

Returns: If button is pressed
Return type: bool

isconnected()¶

Whether it is connected or not

Raises: DeviceError – Occurs if device no longer the same

mode(modev)¶

Set combimode or simple mode

Parameters: modev – List of tuples for a combimode, or integer for simple mode

property name¶

Determine name of device on port

Returns: Device name

static name_for_id(typeid)¶

Translate integer type id to device name (python class)

Parameters: typeid – Type of device
Returns: Name of device

off()¶: Turn off sensor

on()¶: Turn on sensor

reverse()¶: Reverse polarity

select()¶

Request data from mode

Raises: DeviceError – Occurs if device not in valid mode

property threshold_force¶

Threshold force

Getter: Returns threshold force
Setter: Sets threshold force
Returns: Threshold force

property typeid¶

Type ID of device

Returns: Type ID

property typeidcur¶

Type ID currently present

Returns: Type ID

wait_until_pressed(force=1)¶

Wait until the button is pressed

Parameters: force – Optional

wait_until_released(force=0)¶

Wait until the button is released

Parameters: force – Optional

property when_pressed¶

Handle force events

Getter: Returns function to be called when pressed
Setter: Sets function to be called when pressed
Returns: Callback function

property when_released¶

Handle force events

Getter: Returns function to be called when released
Setter: Sets function to be called when released
Returns: Callback function

Example¶

"""Example using force sensor"""

from signal import pause

from buildhat import ForceSensor, Motor

motor = Motor('A')
button = ForceSensor('D', threshold_force=1)

print("Waiting for button to be pressed fully and released")

button.wait_until_pressed(100)
button.wait_until_released(0)

motor.run_for_rotations(1)

print("Wait for button to be pressed")

button.wait_until_pressed()
motor.run_for_rotations(2)


def handle_pressed(force):
    """Force sensor pressed

    :param force: Force value
    """
    print("pressed", force)


def handle_released(force):
    """Force sensor released

    :param force: Force value
    """
    print("released", force)


button.when_pressed = handle_pressed
button.when_released = handle_released
pause()