tone() not working

[ghost]

I've tried on both the MAX32 and UNO32.

[elproducts]

I tested it for my book and it worked fine.
I'll go back and test it again to see if something changed.

Chuck

[GeneApperson]

The attached code works and has been tested for most pin on the Uno32 and a few pin on the Max32. It doesn't currently work on pins 0 & 1, as there is currently no way to disable the serial port.

//************************************************************************
//* Tone.cpp
//*
//* Arduino core files for PIC32
//* Copyright (c) 2010, 2011 by Mark Sproul
//*
//*
//************************************************************************
//* Tone.cpp
//*
//* A Tone Generator Library
//*
//* Based on code by Brett Hagman
//*
//* This library 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 2.1 of the License, or (at your option) any later version.
//*
//* This library 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
//* Lesser General Public License for more details.
//*
//* You should have received a copy of the GNU Lesser General Public
//* License along with this library; if not, write to the Free Software
//* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
//*
//*
//************************************************************************
//* The original tone supported multiple timers and multiple pins
//* the offical Arduino documentation does not
//* I am writing this as per the docs, not per the original code
//************************************************************************
//* Edit History
//************************************************************************
//* Oct 15, 2010 Started on Tone.cpp for PIC32
//* 08/07/2011(GeneApperson) Completed implementation for single tone.
//************************************************************************

#define LANGUAGE_C
//* the Microchip .h files do not know about C++
#include <plib.h>

//#define DEBUG_TONE

#ifdef DEBUG_TONE
#include "WProgram.h"
#include "HardwareSerial.h"
#endif

#include "wiring.h"
#include "pins_arduino.h"

// timerx_toggle_count:
// > 0 - duration specified
// = 0 - stopped
// < 0 - infinitely (until stop() method called, or new play() called)
volatile long timer1_toggle_count;
static uint8_t tone_pin = 255;
volatile uint32_t * tone_pin_port;
volatile uint16_t tone_pin_mask;

#if defined(DEAD)
#define AVAILABLE_TONE_PINS 1

const uint8_t   tone_pin_to_timer_PGM[] = { 2 /*, 3, 4, 5, 1, 0 */ };
static uint8_t tone_pins[AVAILABLE_TONE_PINS] = { 255 /*, 255, 255, 255, 255, 255 */ };

#endif

// frequency (in hertz) and duration (in milliseconds).

//************************************************************************
void tone(uint8_t _pin, unsigned int frequency, unsigned long duration)
{
uint32_t tonePeriod;
uint8_t port;

// Should have an error check here for pin number out of range.

// If a tone is currently playing on a different pin, the function is
// documented to have no effect. If playing on the same pin, change
// the frequency. If not currently playing, initialize the timer.
// This is currently hard coded to use timer1.
if (tone_pin == 255)
{
    // No tone currently playing. Init the timer.
    T1CON = T1_PS_1_256;
    mT1ClearIntFlag();
    ConfigIntTimer1(T1_INT_ON | T1_INT_PRIOR_3 | T1_INT_SUB_PRIOR_1);
}
else if (_pin != tone_pin)
{
    // Tone currently playing on another pin. ignore this call.
    return;
}

// Determine which port and bit are requested.
tone_pin        = _pin; 
port            =   digitalPinToPort(_pin);
tone_pin_port   =   portOutputRegister(port);
tone_pin_mask   =   digitalPinToBitMask(_pin);

// Ensure that the pin is a digital output
pinMode(_pin, OUTPUT);

// Duration 0 means to play forever until stopped. Other values
// mean to play for that many milliseconds.
if (duration > 0)
{
    timer1_toggle_count = (2 * frequency * duration)/1000;
}
else
{
    timer1_toggle_count = -1;
}

TMR1 = 0;
PR1 = ((F_CPU / 256) / 2 / frequency);
T1CONSET = T1_ON;

}

//************************************************************************
void disableTimer(uint8_t _timer)
{
mT1IntEnable(0);
T1CON = 0;;
tone_pin = 255;
}

//************************************************************************
void noTone(uint8_t _pin)
{
int8_t _timer = 1;

if (_pin == tone_pin)
{   
    digitalWrite(_pin, 0);
    disableTimer(_timer);
}

}

//*******************************************************************************************
//* we need the extern C so that the interrupt handler names dont get mangled by C++
extern "C"
{

//* not done yet
//************************************************************************
void __ISR(_TIMER_1_VECTOR, ipl3) Timer1Handler(void)
{

// clear the interrupt flag
mT1ClearIntFlag();

if (timer1_toggle_count != 0)
{
    // toggle the pin
    // The PORTxINV register is at offset +3 from the PORTx register
    *(tone_pin_port+3)  =   tone_pin_mask;

    if (timer1_toggle_count > 0)
    {
        timer1_toggle_count--;
    }
}
else
{
    disableTimer(1);
    // The PORTxCLR register is at offset +1 from the PORTx register
    *(tone_pin_port+1) = tone_pin_mask;     // keep pin low after stop
}

}

};

[ghost]

Note that the code example as shown is missing the <plib.h> following the first #include. Other than that, the code works on my board. So I think we can close this issue.

[GeneApperson]

Apparently, this change didn't make it into the release because it got closed before the fixes had been incorporated into the source tree, so tone still fails on the 20110822 release.

I'll submit the corrected code again as a patch.