为什么全局静态变量重置？

Question

也许我不太了解静态变量。但我的代码不能正常工作。每次变量 Spedometer_Mode 在中断中发生变化时，所有变量都将重置为0.可以重置静态变量吗？这里的省略在哪里？

  

speedometer.h：

volatile static uint16_t Speedometer_WheelLength_mm;                //  Length of the wheel in mm

volatile static bool Speedometer_IsRunning;                 //  When this variable is true, speedometer is processing, OCR0B Interrupt is true
volatile uint8_t Speedometer_Mode;

volatile static uint32_t Speedometer_Speed_mmps;                //  Value, in that stored current speed (mm per seconds)
volatile static uint8_t Speedometer_RevolutionCounter;          //  Counter of the quantity of revolutions (External interrupts)
volatile static uint8_t Speedometer_TimerCounter;               //  

volatile static uint32_t totalDistance;
volatile static uint32_t totalTime;
volatile static uint32_t averageVelocity;
volatile static uint32_t maxVelocity;
volatile static uint32_t currentDistance;

  

speedometer.c：

#include "Speedometer.h"


volatile static uint16_t Speedometer_WheelLength_mm = 2074;                                 //  Default value

volatile uint8_t Speedometer_Mode = SPEEDOMETER_SPEED_MEASUREMENT_MODE;
volatile static bool Speedometer_IsRunning = false;

volatile static uint32_t totalDistance = 0;
volatile static uint32_t totalTime = 0;
volatile static uint32_t averageVelocity = 0;
volatile static uint32_t maxVelocity = 0;
volatile static uint32_t currentDistance = 0;

ISR (INT0_vect)
{
    if (!Speedometer_IsRunning)
    {
        Speedometer_IsRunning = true;
        Speedometer_RevolutionCounter = 1;
        Speedometer_TimerCounter = 1;

        OCR1A = 0x03D0;                                                                                 //  If F_CPU = 1MHz and prescaler = 1024, T = 1 second
        OCR1B = 0x03D0;//?????????????????????
        TCCR1B |= 1 << WGM12 | 1 << CS12 | 0 << CS11 | 1 << CS10;                                       //  Prescaler = F_CPU / 1024
        TIMSK1 |= 1 << OCIE1A | 1 << OCIE1B;                                                            //  Enable timer interrupts
    }
    else    Speedometer_RevolutionCounter++;
}

ISR (TIMER1_COMPA_vect)
{
    if (Speedometer_TimerCounter < SPEEDOMETER_GENERAL_SAMPLE_TIME)
    {
        Speedometer_Speed_mmps = (Speedometer_WheelLength_mm * Speedometer_RevolutionCounter) / Speedometer_TimerCounter;
        Speedometer_TimerCounter++;
    }
    else
    {
        Speedometer_Speed_mmps = (Speedometer_WheelLength_mm * Speedometer_RevolutionCounter) / Speedometer_TimerCounter;
        if (Speedometer_Speed_mmps == 0)
        {
            TCCR1B &= ~(1 << WGM12 | 1 << CS12 | 0 << CS11 | 1 << CS10);
            TIMSK1 &= ~(1 << OCIE1A | OCIE1B);
            Speedometer_IsRunning = false;

            return;
        }
        Speedometer_RevolutionCounter = 0;
        Speedometer_TimerCounter = 1;
    }
}

ISR (TIMER1_COMPB_vect)
{
    uint32_t currentVelocity = Speedometer_Speed_mmps / 1000;
    totalDistance += currentVelocity;
    currentDistance += currentVelocity;
    totalTime++;
    averageVelocity = totalDistance / totalTime;
    if (currentVelocity > maxVelocity)  maxVelocity = currentVelocity;
}

ISR (TIMER0_COMPA_vect)                                                 //  Button's state polling
{
...
case GEEKSPORT_SPEEDOMETER_MODE:
                    {
                        if (Speedometer_Mode < (SPEEDOMETER_LAST_MODE - 1)) Speedometer_Mode++;
                        else Speedometer_Mode = SPEEDOMETER_SPEED_MEASUREMENT_MODE;

                        break;
                    }
...
}

如何纠正这种情况？

P.S。：对不起我的英语，我正在研究它。