Gets readings from the two bump sensors on the front of the 3pi+ 32U4. More...

#include <Pololu3piPlus32U4BumpSensors.h>

Public Member Functions
void	calibrate (uint8_t count=50)
	Calibrates the bump sensors. More...

uint8_t	read ()
	Reads both bump sensors. More...

bool	leftChanged ()
	Indicates whether the left bump sensor's state has changed. More...

bool	rightChanged ()
	Indicates whether the right bump sensor's state has changed. More...

bool	leftIsPressed ()
	Indicates whether the left bump sensor is pressed. More...

bool	rightIsPressed ()
	Indicates whether the right bump sensor is pressed. More...

Public Attributes
uint16_t	marginPercentage = 50
	The amount, as a percentage, that will be added to the measured baseline to get the threshold. More...

uint16_t	baseline [2]
	Baseline readings obtained from calibration. More...

uint16_t	threshold [2]
	Thresholds for bump sensor press detection. More...

uint16_t	sensorValues [2]
	Raw reflectance sensor readings. More...

uint16_t	timeout = defaultTimeout
	Timeout for bump sensor readings (in microseconds). More...

Static Public Attributes
static const uint16_t	defaultTimeout = 4000
	Default timeout for RC sensors (in microseconds). More...

static const uint8_t	emitterPin = 11

static const uint8_t	bumpLeftPin = 4

static const uint8_t	bumpRightPin = 5

Detailed Description

Gets readings from the two bump sensors on the front of the 3pi+ 32U4.

Definition at line 23 of file Pololu3piPlus32U4BumpSensors.h.

Member Function Documentation

◆ calibrate()

void Pololu3piPlus32U4::BumpSensors::calibrate ( uint8_t count = 50 )

Calibrates the bump sensors.

Parameters

count The number of times to read the sensors during calibration. The default is 50.

This method reads the bump sensors a number of times for calibration. You should call it while the bump sensors are not pressed and before using them in your program.

Calling this function obtains a set of baseline readings that should should represent the raw sensor readings while the bump sensors are not pressed. The library uses these baseline values and an additional margin (marginPercentage, defined as a percentage of the baselines) to derive thresholds that the sensors must exceed to register as pressed:

\[ {\text{threshold} = \text{baseline} \times \frac{100 + \text{marginPercentage}}{100}} \]

Definition at line 44 of file Pololu3piPlus32U4BumpSensors.cpp.

◆ leftChanged()

bool Pololu3piPlus32U4::BumpSensors::leftChanged ( )

inline

Indicates whether the left bump sensor's state has changed.

Returns: True if the left bump sensor's state has changed between the second-to-last and the last call to read(); false otherwise.

Definition at line 73 of file Pololu3piPlus32U4BumpSensors.h.

◆ leftIsPressed()

bool Pololu3piPlus32U4::BumpSensors::leftIsPressed ( )

inline

Indicates whether the left bump sensor is pressed.

Returns: True if the left bump sensor was pressed during the most recent call to read(); false otherwise.

Definition at line 86 of file Pololu3piPlus32U4BumpSensors.h.

◆ read()

uint8_t Pololu3piPlus32U4::BumpSensors::read ( )

Reads both bump sensors.

Returns: A bit field indicating whether each bump sensor is pressed. The bits representing each sensor are defined by the BumpSide enum.

For example, a return value of 2 (0b10 in binary) indicates:

The right bump sensor is pressed, since bit 1 (BumpRight) is set.
The left bump sensor is not pressed, since bit 0 (BumpLeft) is cleared.

Instead of checking the return value of this method, you can instead call read() and then use the functions leftChanged(), rightChanged(), leftIsPressed(), and rightIsPressed() to get information about the bump sensors.

Definition at line 67 of file Pololu3piPlus32U4BumpSensors.cpp.