upm  1.7.1
Sensor/Actuator repository for libmraa (v2.0.0)
Public Member Functions | Protected Attributes

API for LDT0-028 PZT film-based sensors, such as a Grove Piezo Vibration sensor. More...

Detailed Description

This module defines the LDT0-028 interface for libupm-ldt0028

ldt0028.jpg
const int NUMBER_OF_SECONDS = 10;
const int MICROSECONDS_PER_SECOND = 1000000;
const int SAMPLES_PER_SECOND = 50;
const int THRESHOLD = 100;
// Create the LDT0-028 Piezo Vibration Sensor object using AIO pin 0
upm::LDT0028 sensor(0);
// Read the signal every 20 milliseconds for 10 seconds
std::cout << "For the next " << NUMBER_OF_SECONDS << " seconds, " << SAMPLES_PER_SECOND
<< " samples will be taken every second." << std::endl
<< std::endl;
uint16_t buffer[NUMBER_OF_SECONDS * SAMPLES_PER_SECOND];
for (int i = 0; i < NUMBER_OF_SECONDS * SAMPLES_PER_SECOND; i++) {
buffer[i] = (uint16_t) sensor.getSample();
upm_delay_us(MICROSECONDS_PER_SECOND / SAMPLES_PER_SECOND);
}
// Print the number of times the reading was greater than the threshold
int count = 0;
for (int i = 0; i < NUMBER_OF_SECONDS * SAMPLES_PER_SECOND; i++) {
if (buffer[i] > THRESHOLD) {
count++;
}
}
std::cout << sensor.name() << " exceeded the threshold value of " << THRESHOLD << " a total of "
<< count << " times," << std::endl
<< "out of a total of " << NUMBER_OF_SECONDS * SAMPLES_PER_SECOND << " readings."
<< std::endl
<< std::endl;
// Print a graphical representation of the average value sampled
// each second for the past 10 seconds, using a scale factor of 15
std::cout << "Now printing a graphical representation of the average reading " << std::endl
<< "each second for the last " << NUMBER_OF_SECONDS << " seconds." << std::endl;
const int SCALE_FACTOR = 15;
for (int i = 0; i < NUMBER_OF_SECONDS; i++) {
long sum = 0;
for (int j = 0; j < SAMPLES_PER_SECOND; j++) {
sum += buffer[i * SAMPLES_PER_SECOND + j];
}
double average = (double) sum / (double) SAMPLES_PER_SECOND;
int stars_to_print = (int) round(average / SCALE_FACTOR);
std::cout << "(" << std::setw(4) << (int) round(average) << ") | ";
for (int j = 0; j < stars_to_print; j++) {
std::cout << "*";
}
std::cout << std::endl;
}
// Delete the sensor object

Public Member Functions

 LDT0028 (unsigned int pin)
 
 ~LDT0028 ()
 
std::string name ()
 
int getSample ()
 

Protected Attributes

std::string m_name
 name of this sensor
 
mraa_aio_context m_pin
 AIO pin.
 

Constructor & Destructor Documentation

LDT0028 ( unsigned int  pin)

LDT0028 constructor

Parameters
pinAIO pin where the sensor is connected
~LDT0028 ( )

LDT0028 destructor

Member Function Documentation

std::string name ( )

Returns the name of this sensor

Returns
Name of this sensor
int getSample ( )

Returns one sample from this sensor

Returns
One value from this sensor

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