物体探测器#

初始化 ObjectDetector 类#

使用以下构造函数创建对象传感器：

ObjectDetector(port, reverse)

此构造函数使用两个参数：

范围

描述

port

物体传感器连接到的 3 线端口，无论它是 大脑 上的端口，还是 3 线扩展器 上的端口。

reverse

Optional. Set this to reverse the detection logic. The default is False.

必须先创建 Brain 或 3-Wire Expander，然后才能使用 ObjectDetector 类构造函数创建对象。

# Create the Brain.
brain = Brain()
# Construct an ObjectSensor "objdet" with the
# ObjectDetector class.
objdet = ObjectDetector(brain.three_wire_port.a)

This objdet object will be used in all subsequent examples throughout this API documentation when referring to ObjectDetector class methods.

类方法#

reflectivity()#

The reflectivity(units) method returns the reflectivity measured by the Object Sensor. The reflectivity is an estimation based on the raw value of the Object Sensor.

反射率为 0% 时，原始值等于或大于 3000。反射率为 100% 时，原始值等于 0。

参数

描述

单位

Optional. The only valid unit for reflectivity is PERCENT.

**返回：**物体传感器测量的反射率在 0% - 100% 范围内。

# Print the Object Sensor's current reflectivity to the
# Brain's screen.
brain.screen.print(objdet.reflectivity())

set_threshold()#

The set_threshold(value, units) method sets the detection threshold for the Object Sensor to a specific value.

参数

描述

价值

物体检测的反射率阈值。范围为 0 - 100。

**返回：**无。

# Set the Object Sensor's reflectivity threhold to 50%.
objdet.set_threshold(50)

is_object_detected()#

The is_object_detected() method returns if an object is detected.

Returns: True if an object is detected. False if one is not.

changed()#

The changed(callback, arg) method registers a callback function for when the value of an Object Sensor changes.

参数

描述

打回来

当对象传感器的值发生变化时调用的回调函数。

arg

**可选。**传递给回调函数的参数元组。

**返回：**事件类的一个实例。

# Define a function detector_changed().
def detector_changed():
    # The brain will print that the Object Sensor value
    # changed on the Brain's screen.
    brain.screen.print("Object Sensor value changed")

# Run detector_changed when the value of the
# Object Sensor changes.
objdet.changed(detector_changed)

object_detected()#

The object_detected(callback, arg) method registers a callback function for when an object is detected.

参数

描述

打回来

当检测到物体时调用的回调函数。

arg

**可选。**传递给回调函数的参数元组。

**返回：**事件类的一个实例。

# Define a function detected().
def detected():
    # The Brain will print that an object was detected
    # on the Brain's screen.
    brain.screen.print("object detected")

# Run detected when the Object Sensor detects an object.
objdet.object_detected(detected)

object_lost()#

The object_lost(callback, arg) method registers a callback function for when an object is lost.

参数

描述

打回来

当对象丢失时调用的回调函数。

arg

**可选。**传递给回调函数的参数元组。

**返回：**事件类的一个实例。

# Define a function lost().
def lost():
    # The Brain will print that an object was lost on the
    # Brain's screen.
    brain.screen.print("object lost")

# Run lost() when the Object Sensor loses an object.
objdet.object_lost(lost)
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