hal.h

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//------------------------------------------------------------------------------
// Module:        CHAL
// Description:   Hardware abstraction for buzzer control and serial pin routing.
// Author:        R. Zuehlsdorff, ralf.zuehlsdorff@t-online.de
// Created:       2026-01-18
// License:       MIT License (https://opensource.org/license/mit/)
//------------------------------------------------------------------------------
// Change Log:
// 2026-01-18     R. Zuehlsdorff        Initial creation
//------------------------------------------------------------------------------
 
#pragma once
 
 
// Include Circle core components
#include <circle/types.h>
#include <circle/timer.h>
#include <circle/logger.h>
#include <circle/usertimer.h>
#include <circle/gpiopin.h>
 
// Forward declarations and includes for classes used in this module
 
 
class CHAL
{
public:
    CHAL(CInterruptSystem *pInterruptSystem, CTimer *pTimer);
    ~CHAL(void);
 
    // \return Pointer to singleton CHAL instance
    static CHAL *Get(void);
 
    // Initialize PWM hardware (call once during startup)
    boolean Initialize(void);
 
    // 800 Hz PWM Buzzer with configured volume and 250ms duration
    void BEEP(void);
 
    // 800 Hz Click sound for key press
    void Click(void);
 
    // Start Buzzer with specified duty cycle and duration
    // duty: 0-100% duty cycle
    // duration: milliseconds (0 = continuous)
    void StartBuzzer(unsigned duty, unsigned duration = 0);
 
    // Stop Buzzer output
    void StopBuzzer(void);
 
    // Switch RxD <-> TxD pins for RS-232 mode
    void SwitchRxTx(void);
 
    // Apply configured RX/TX swap state
    void ConfigureRxTxSwap(boolean enableSwap);
 
    // Apply configured buzzer volume (0-100)
    void ConfigureBuzzerVolume(unsigned volumePercent);
 
    // Update function - call regularly from main loop to handle auto-stop
    void Update(void);
 
private:
    static void UserTimerHandler(CUserTimer *pTimer, void *pParam);
    void HandleTimerTick();
    void StopInternal(boolean logMessage);
 
private:
    enum
    {
        PWMFrequencyHz  = 800,
        PWMPeriodMicros = 1000000U / PWMFrequencyHz,
        PWMGPIOPin      = 12,
        RxTXSwitchPin   = 16
    };
 
    CInterruptSystem  *m_pInterruptSystem;
    CTimer            *m_pTimer;
    CUserTimer         m_UserTimer;
    CGPIOPin           m_Pin;
    CGPIOPin           m_RxTXSwitchPin;
 
    boolean            m_bGPIO16Configured;
    boolean            m_bBuzzerPinConfigured;
    boolean            m_bTimerInitialized;
    boolean            m_bActive;
    boolean            m_bUseTimer;
    boolean            m_bHighPhase;
    boolean            m_bRxTxSwitchMode;
    unsigned           m_nConfiguredBuzzerVolume;
    unsigned           m_nStopTicks;
    unsigned           m_nOnMicros;
    unsigned           m_nOffMicros;
};