PinObserver.h

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/* Copyright (c) 2018-2022 Skyward Experimental Rocketry
 * Authors: Luca Erbetta, Alberto Nidasio, Niccolò Betto
 *
 * 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 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.
 */
 
#pragma once
 
#include <scheduler/TaskScheduler.h>
#include <utils/GpioPinCompare.h>
 
#include <chrono>
#include <functional>
#include <map>
 
namespace Boardcore
{
 
enum class PinTransition : uint8_t
{
    FALLING_EDGE = 0,  
    RISING_EDGE        
};
 
class PinObserver
{
public:
    using Clock     = std::chrono::steady_clock;
    using TimePoint = Clock::time_point;
 
    struct PinData
    {
        // Number of periods the value was the same.
        uint32_t periodCount;
        // Last time the pin transitioned to a different state
        PinObserver::TimePoint lastTransitionTs;
        // Time when the last state change was detected
        PinObserver::TimePoint lastStateChangeTs;
        bool lastState;         
        uint32_t changesCount;  
 
        std::chrono::milliseconds getLastDetectionDelay() const
        {
            return std::chrono::duration_cast<std::chrono::milliseconds>(
                lastStateChangeTs - lastTransitionTs);
        }
    };
 
    using PinCallback =
        std::function<void(PinTransition transition, const PinData& data)>;
 
    struct PinConfig
    {
        PinObserver::PinCallback callback;  
        uint32_t threshold;  
        bool reverted;       
    };
 
    PinObserver(TaskScheduler& scheduler, uint32_t pollInterval = 20)
        : scheduler{scheduler}, pollInterval{pollInterval}
    {
    }
 
    bool registerPinCallback(miosix::GpioPin pin, PinCallback callback,
                             uint32_t detectionThreshold = 1,
                             bool reverted               = false);
 
    PinData getPinData(miosix::GpioPin pin);
 
    void resetPinChangesCount(miosix::GpioPin pin);
 
private:
    void periodicPinValueCheck(miosix::GpioPin pin);
 
    TaskScheduler& scheduler;
    uint32_t pollInterval;
 
    struct PinEntry
    {
        PinConfig config;
        PinData data;
    };
 
    std::map<miosix::GpioPin, PinEntry, GpioPinCompare> callbacks;
};
 
// Re-export the PinData type, was moved inside PinObserver for convenience
using PinData = PinObserver::PinData;
 
}  // namespace Boardcore