File content as of revision 1:cb791d277230:

/* PulsePosition Library for Teensy 3.1
 * High resolution input and output of PPM encoded signals
 * http://www.pjrc.com/teensy/td_libs_PulsePosition.html
 * Copyright (c) 2014, Paul Stoffregen, paul@pjrc.com
 *
 * Development of this library was funded by PJRC.COM, LLC by sales of Teensy
 * boards.  Please support PJRC's efforts to develop open source software by
 * purchasing Teensy or other PJRC products.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice, development funding notice, and this permission
 * notice shall be included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#include "mbed.h"

#define PULSEPOSITION_MAXCHANNELS 16
#define FALLING 2
#define RISING 3

struct ftm_channel_struct {
    uint32_t csc;
    uint32_t cv;
};

class PulsePositionOutput
{
public:
    PulsePositionOutput(void);
    PulsePositionOutput(int polarity);
    bool begin(PinName txPin); // txPin can be 5,6,9,10,20,21,22,23
    bool begin(PinName txPin, PinName framePin);
    bool write(uint8_t channel, float microseconds);
    friend void ftm0_isr(void);
private:
    void isr(void);
    uint32_t pulse_width[PULSEPOSITION_MAXCHANNELS+1];
    uint32_t pulse_buffer[PULSEPOSITION_MAXCHANNELS+1];
    uint32_t pulse_remaining;
    DigitalOut *framePinReg;
    volatile uint8_t framePinMask;
    struct ftm_channel_struct *ftm;
    uint8_t state;
    uint8_t current_channel;
    uint8_t total_channels;
    uint8_t total_channels_buffer;
    uint8_t cscSet;
    uint8_t cscClear;
    static PulsePositionOutput *list[8];
    static uint8_t channelmask;
};


class PulsePositionInput
{
public:
    PulsePositionInput(void);
    PulsePositionInput(int polarity);
    bool begin(PinName rxPin); // rxPin can be 5,6,9,10,20,21,22,23
    int available(void);
    float read(uint8_t channel);
    friend void ftm0_isr(void);
private:
    void isr(void);
    struct ftm_channel_struct *ftm;
    uint32_t pulse_width[PULSEPOSITION_MAXCHANNELS];
    uint32_t pulse_buffer[PULSEPOSITION_MAXCHANNELS];
    uint32_t prev;
    uint8_t write_index;
    uint8_t total_channels;
    uint8_t cscEdge;
    bool available_flag;
    static bool overflow_inc;
    static uint16_t overflow_count;
    static PulsePositionInput *list[8];
    static uint8_t channelmask;
};