电位器#
初始化电位器类#
使用以下构造函数创建电位器:
Potentiometer(port)
此构造函数使用一个参数:
范围 |
描述 |
---|---|
|
必须先创建 Brain 或 3-Wire Expander,然后才能使用电位器类构造函数创建对象。
# Create the Brain.
brain = Brain()
# Construct a Potentiometer "pot" with the Potentiometer class.
pot = Potentiometer(brain.three_wire_port.a)
This pot
object will be used in all subsequent examples throughout this API documentation when referring to Potentiometer class methods.
类方法#
angle()#
The angle(units)
method returns the angle measured by the Potentiometer.
参数 |
描述 |
---|---|
单位 |
Optional. A valid RotationUnits type or |
**返回:**电位器测量的角度
# Print the current angle of the Potentiometer to the
# Brain's screen.
brain.screen.print(pot.angle())
changed()#
The changed(callback, arg)
method registers a callback function for when the value measured by the Potentiometer changes.
参数 |
描述 |
---|---|
打回来 |
当电位器测量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:**无。
# Define a function potentiometer_changed().
def potentiometer_changed():
# The Brain will print that the Potentiometer value changed
# on the Brain's screen.
brain.screen.print("potentiometer changed")
# Run potentiometer_changed when the value measured by
# the Potentiometer changes.
pot.changed(potentiometer_changed)