/*
* #%L
* **********************************************************************
* ORGANIZATION : Pi4J
* PROJECT : Pi4J :: Java Examples
* FILENAME : ADS1015DistanceSensorExample.java
*
* This file is part of the Pi4J project. More information about
* this project can be found here: http://www.pi4j.com/
* **********************************************************************
* %%
* Copyright (C) 2012 - 2013 Pi4J
* %%
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
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* #L%
*/
import java.io.IOException;
import java.text.DecimalFormat;
import com.pi4j.component.sensor.DistanceSensorChangeEvent;
import com.pi4j.component.sensor.DistanceSensorListener;
import com.pi4j.component.sensor.impl.DistanceSensorComponent;
import com.pi4j.gpio.extension.ads.ADS1015GpioProvider;
import com.pi4j.gpio.extension.ads.ADS1015Pin;
import com.pi4j.gpio.extension.ads.ADS1x15GpioProvider.ProgrammableGainAmplifierValue;
import com.pi4j.io.gpio.GpioController;
import com.pi4j.io.gpio.GpioFactory;
import com.pi4j.io.gpio.GpioPinAnalogInput;
import com.pi4j.io.i2c.I2CBus;
/**
* <p>
* This example code demonstrates how to use the ADS1015 Pi4J GPIO interface
* for analog input pins.
* </p>
*
* @author Robert Savage
*/
public class ADS1015DistanceSensorExample {
public static void main(String args[]) throws InterruptedException, IOException {
System.out.println("<--Pi4J--> ADS1015 Distance Sensor Example ... started.");
// number formatters
final DecimalFormat df = new DecimalFormat("#.##");
final DecimalFormat pdf = new DecimalFormat("###.#");
// create gpio controller
final GpioController gpio = GpioFactory.getInstance();
// create custom ADS1015 GPIO provider
final ADS1015GpioProvider gpioProvider = new ADS1015GpioProvider(I2CBus.BUS_1, ADS1015GpioProvider.ADS1015_ADDRESS_0x48);
// provision gpio analog input pins from ADS1015
final GpioPinAnalogInput distanceSensorPin = gpio.provisionAnalogInputPin(gpioProvider, ADS1015Pin.INPUT_A0, "DistanceSensor-A0");
// ATTENTION !!
// It is important to set the PGA (Programmable Gain Amplifier) for all analog input pins.
// (You can optionally set each input to a different value)
// You measured input voltage should never exceed this value!
//
// In my testing, I am using a Sharp IR Distance Sensor (GP2Y0A21YK0F) whose voltage never exceeds 3.3 VDC
// (http://www.adafruit.com/products/164)
//
// PGA value PGA_4_096V is a 1:1 scaled input,
// so the output values are in direct proportion to the detected voltage on the input pins
gpioProvider.setProgrammableGainAmplifier(ProgrammableGainAmplifierValue.PGA_4_096V, ADS1015Pin.ALL);
// Define a threshold value for each pin for analog value change events to be raised.
// It is important to set this threshold high enough so that you don't overwhelm your program with change events for insignificant changes
gpioProvider.setEventThreshold(150, ADS1015Pin.ALL);
// Define the monitoring thread refresh interval (in milliseconds).
// This governs the rate at which the monitoring thread will read input values from the ADC chip
// (a value less than 50 ms is not permitted)
gpioProvider.setMonitorInterval(100);
// create a distance sensor based on an analog input pin
DistanceSensorComponent distanceSensor = new DistanceSensorComponent(distanceSensorPin);
// build a distance coordinates mapping (estimated distance at raw values)
distanceSensor.addCalibrationCoordinate(21600, 13);
distanceSensor.addCalibrationCoordinate(21500, 14);
distanceSensor.addCalibrationCoordinate(21400, 15);
distanceSensor.addCalibrationCoordinate(21200, 16);
distanceSensor.addCalibrationCoordinate(21050, 17);
distanceSensor.addCalibrationCoordinate(20900, 18);
distanceSensor.addCalibrationCoordinate(20500, 19);
distanceSensor.addCalibrationCoordinate(20000, 20);
distanceSensor.addCalibrationCoordinate(15000, 30);
distanceSensor.addCalibrationCoordinate(12000, 40);
distanceSensor.addCalibrationCoordinate(9200, 50);
distanceSensor.addCalibrationCoordinate(8200, 60);
distanceSensor.addCalibrationCoordinate(6200, 70);
distanceSensor.addCalibrationCoordinate(4200, 80);
distanceSensor.addListener(new DistanceSensorListener()
{
@Override
public void onDistanceChange(DistanceSensorChangeEvent event)
{
// RAW value
double value = event.getRawValue();
// Estimated distance
double distance = event.getDistance();
// percentage
double percent = ((value * 100) / ADS1015GpioProvider.ADS1015_RANGE_MAX_VALUE);
// approximate voltage ( *scaled based on PGA setting )
double voltage = gpioProvider.getProgrammableGainAmplifier(distanceSensorPin).getVoltage() * (percent/100);
// display output
System.out.print("\r DISTANCE=" + df.format(distance) + "cm : VOLTS=" + df.format(voltage) + " | PERCENT=" + pdf.format(percent) + "% | RAW=" + value + " ");
}
});
// keep program running for 10 minutes
for (int count = 0; count < 600; count++) {
Thread.sleep(1000);
}
// stop all GPIO activity/threads by shutting down the GPIO controller
// (this method will forcefully shutdown all GPIO monitoring threads and scheduled tasks)
gpio.shutdown();
System.out.print("");
}
}