ME405_FP_Encoder.ME405_FP_Encoder Class Reference

Runs operations and returns values specific to the encoder count. More...

Public Member Functions
def	__init__ (self, tim, pin1, pin2)
	Initiates encoder operations using approprate timers and pins. More...
def	update (self)
	Updates the encoder count and corrects for overflow. More...
def	getPosition (self)
	Gives the last stored position of the encoder arm. More...
def	setPosition (self, reset_value)
	Sets the encoder count to a desired value. More...
def	getDelta (self)
	Returns the change between the last two counts in update. More...

Public Attributes
	AngList
	DatumCnt
	Initial value that will be used to measure a change in count.
	DeltaCnt
	Establishes the change in count. More...
	theta
	tim
	The timer from which the encoder counts.
	pin1
	One of two pins needed for collecting data on motor ops.
	timCh1
	One of two channels needed for the encoder operation.
	pin2
	One of two pins needed for collecting data on motor ops.
	timCh2
	One of two channels needed for the encoder operation.
	newCnt
	A count value that will be updated each time update is called. More...

Detailed Description

Runs operations and returns values specific to the encoder count.

Class for updating, getting, setting, and computing the change in the encoder count.

Constructor & Destructor Documentation

__init__()

def ME405_FP_Encoder.ME405_FP_Encoder.__init__	(		self,
			tim,
			pin1,
			pin2
	)

Initiates encoder operations using approprate timers and pins.

The encoder architecture requires two channels from which the timer reads in order to determine directional differences

Member Function Documentation

getDelta()

def ME405_FP_Encoder.ME405_FP_Encoder.getDelta

(

self

)

Returns the change between the last two counts in update.

Returns

DeltaCnt; The change in the count

getPosition()

def ME405_FP_Encoder.ME405_FP_Encoder.getPosition

(

self

)

Gives the last stored position of the encoder arm.

Returns

theta; The position of the encoder arm in ticks

setPosition()

def ME405_FP_Encoder.ME405_FP_Encoder.setPosition	(		self,
			reset_value
	)

Sets the encoder count to a desired value.

Parameters

reset_value;

The position one wishes to set the encoder to

update()

def ME405_FP_Encoder.ME405_FP_Encoder.update

(

self

)

Updates the encoder count and corrects for overflow.

Returns

theta The position of the encoder arm in ticks

Member Data Documentation

DeltaCnt

ME405_FP_Encoder.ME405_FP_Encoder.DeltaCnt

Establishes the change in count.

The change in count represents the change in the location of the motor arm between sample periods. This change in count conveys direction and velocity data. The count can only go so high before an overflow condtion occurs, meaning we have to correct the overflow in order to get a continuous representation of the motor;s motion.

newCnt

ME405_FP_Encoder.ME405_FP_Encoder.newCnt

A count value that will be updated each time update is called.

A change in value for newCnt, or for that matter any value based on timer counts, will only occur if the arm of the motor is rotated, because the rotation of the motor arm is what brings about the change in pulses of the encoder, which is interpreted by the timer attached to the encoder channel and returns a change in count to reflect the change in the motor arm position

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The documentation for this class was generated from the following file:

• ME405_FP_Encoder.py