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Pi4J Plugin for the PIGPIO I/O Providers
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package com.pi4j.plugin.pigpio.provider.pwm;
/*-
* #%L
* **********************************************************************
* ORGANIZATION : Pi4J
* PROJECT : Pi4J :: PLUGIN :: PIGPIO I/O Providers
* FILENAME : PiGpioPwmHardware.java
*
* This file is part of the Pi4J project. More information about
* this project can be found here: https://pi4j.com/
* **********************************************************************
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Lesser Public License for more details.
*
* You should have received a copy of the GNU General Lesser Public
* License along with this program. If not, see
* .
* #L%
*/
import com.pi4j.context.Context;
import com.pi4j.exception.InitializeException;
import com.pi4j.io.exception.IOException;
import com.pi4j.io.pwm.Pwm;
import com.pi4j.io.pwm.PwmConfig;
import com.pi4j.io.pwm.PwmPolarity;
import com.pi4j.io.pwm.PwmProvider;
import com.pi4j.library.pigpio.PiGpio;
import com.pi4j.library.pigpio.PiGpioMode;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* PiGpioPwmHardware class.
*
* @author Robert Savage (http://www.savagehomeautomation.com)
* @version $Id: $Id
*/
public class PiGpioPwmHardware extends PiGpioPwmBase implements Pwm {
protected Logger logger = LoggerFactory.getLogger(this.getClass());
private boolean initializing = false;
// fixed range for hardware PWM
/** Constant RANGE=1000000 */
public static int RANGE = 1000000;
/**
* Constructor for PiGpioPwmHardware.
*
* @param piGpio a {@link com.pi4j.library.pigpio.PiGpio} object.
* @param provider a {@link com.pi4j.io.pwm.PwmProvider} object.
* @param config a {@link com.pi4j.io.pwm.PwmConfig} object.
*/
public PiGpioPwmHardware(PiGpio piGpio, PwmProvider provider, PwmConfig config) {
super(piGpio, provider, config, RANGE);
}
/**
* {@inheritDoc}
*/
@Override
public Pwm initialize(Context context) throws InitializeException {
try {
initializing = true;
// TODO :: SET PIN ALT MODES FOR HARDWARE PWM ON COMPUTE MODULE
// 12 PWM channel 0 All models but A and B
// 13 PWM channel 1 All models but A and B
// 18 PWM channel 0 All models
// 19 PWM channel 1 All models but A and B
// 40 PWM channel 0 Compute module only
// 41 PWM channel 1 Compute module only
// 45 PWM channel 1 Compute module only
// 52 PWM channel 0 Compute module only
// 53 PWM channel 1 Compute module only
if(this.address() == 12 || this.address() == 13 || this.address() == 41 || this.address() == 42 || this.address() == 45) {
piGpio.gpioSetMode(this.address(), PiGpioMode.ALT0);
}
else if(this.address() == 18 || this.address() == 19) {
piGpio.gpioSetMode(this.address(), PiGpioMode.ALT0);
}
// else{
// throw new IOException(" UNSUPPORTED HARDWARE PWM PIN: " + this.address());
// }
// inversed polarity is not supported
if (config.polarity() != null) {
if(config.polarity() == PwmPolarity.INVERSED){
throw new IOException(" INVERSED POLARITY UNSUPPORTED; PWM PIN: " + this.address());
}
}
// set pin mode to output
piGpio.gpioSetMode(this.address(), PiGpioMode.OUTPUT);
// get actual PWM frequency
this.actualFrequency = piGpio.gpioGetPWMfrequency(this.address());
// get current frequency from config or from actual PWM pin
if (config.frequency() != null) {
this.frequency = config.frequency();
} else {
this.frequency = this.actualFrequency;
}
// get current duty-cycle from config or set to default 50%
if (config.dutyCycle() != null) {
this.dutyCycle = config.dutyCycle();
} else {
// get updated duty-cycle value from PiGpio
this.dutyCycle = 50; // default duty-cycle is 50% of total range
}
// apply an initial value if configured
if(config.initialValue() != null){
try {
if(this.config.initialValue() <= 0){
this.off();
} else {
this.on(this.config.initialValue());
}
} catch (IOException e) {
throw new InitializeException(e);
}
}
// done initializing
initializing = false;
}
catch (Exception e){
initializing = false;
throw new InitializeException(e);
}
return this;
}
/** {@inheritDoc} */
@Override
public Pwm on() throws IOException {
try {
// set PWM frequency & duty-cycle; enable PWM signal
piGpio.gpioHardwarePWM(this.address(), this.frequency, calculateActualDutyCycle(this.dutyCycle));
// get actual PWM frequency
this.actualFrequency = piGpio.gpioGetPWMfrequency(this.address());
// update tracking state
this.onState = (this.frequency > 0 && this.dutyCycle > 0);
}
catch (Exception e){
logger.error(e.getMessage(), e);
throw new IOException(e);
}
return this;
}
/** {@inheritDoc} */
@Override
public Pwm off() throws IOException{
try {
// This is a hack to get the hardware PWM signal to stop if an initial
// value was configured. It seems PIPGIO must actually perform a
// change value to apply a "ZERO" frequency & duty-cycle after
// the library is first initialized and the PWM was not active
if(initializing) {
piGpio.gpioHardwarePWM(this.address(), 1, 1);
}
// set PWM duty-cycle and enable PWM
piGpio.gpioHardwarePWM(this.address(), 0, 0);
// update tracking state
this.onState = false;
}
catch (Exception e){
logger.error(e.getMessage(), e);
throw new IOException(e);
}
return this;
}
}