在已知头文件#include <stdint.h>,#include <TFTv2.h>,#include <SPI.h>并且只能使用两个按钮的情况下，使用Arduino控制显示屏ili9341,在屏幕上显示一个尽可能大的时钟表盘，包含12个刻度和对应的1~12数字，以及一个秒针。秒针最初向上指向数字12。 () Arduino 上连接1个按钮。按钮第一次按下，秒表开始计时，秒针要准确地转动。按钮第二次按下，秒针暂停，在时钟表盘旁边用数字显示过去了多少秒(精确到0.01秒)。按钮第三次按下，秒针接着继续转动。第四次按下，秒针再次暂停，在时钟表盘旁边换行用数字显示过去了多少秒(精确到0.01秒)。第五次按下，同第三次……如此重复。 (iii)使用定时暴进行准确的计时。Arduino 上再加1个按钮，此按钮按下时，秒针归零。全部重新开始。如何在仿真平台上实现

首先，需要定义一些常量和变量，如屏幕尺寸、刻度半径、数字半径、秒针长度、按钮引脚等。代码如下：

#include <stdint.h>
#include <TFTv2.h>
#include <SPI.h>

#define SCREEN_WIDTH  320
#define SCREEN_HEIGHT 240
#define SCALE_RADIUS  80
#define NUM_RADIUS    60
#define SEC_LENGTH    70
#define BUTTON_PIN    2

TFT TFTscreen = TFT(SCREEN_WIDTH, SCREEN_HEIGHT);
volatile bool buttonPressed = false;
volatile bool reset = false;
volatile uint32_t startMillis = 0;
volatile uint32_t pauseMillis = 0;

void interruptHandler() {
  buttonPressed = true;
}

接着，在`setup()`函数中初始化TFT屏幕、SPI接口、按钮以及定时器，代码如下：

void setup() {
  TFTscreen.begin();
  SPI.begin();
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(BUTTON_PIN), interruptHandler, FALLING);
  Timer1.initialize(10000);
  Timer1.attachInterrupt(timerHandler);
}

在`loop()`函数中，首先判断按钮是否按下，如果按下了，则执行相应的操作。如果是第一次按下，记录当前时间戳；如果是第二次按下，计算过去了多少秒并显示在屏幕上；如果是第三次按下，恢复计时；如果是第四次按下，同第二次按下；如果是第五次按下，同第三次按下。代码如下：

void loop() {
  static uint8_t state = 0;
  static uint32_t prevMillis = 0;
  if (buttonPressed) {
    buttonPressed = false;
    switch (state) {
      case 0:
        startMillis = millis();
        state = 1;
        break;
      case 1:
        pauseMillis = millis();
        state = 2;
        break;
      case 2:
        startMillis += millis() - pauseMillis;
        state = 1;
        break;
      case 3:
        pauseMillis = millis();
        state = 4;
        break;
      case 4:
        uint32_t elapsedMillis = pauseMillis - startMillis;
        uint16_t seconds = elapsedMillis / 1000;
        uint16_t millisecs = elapsedMillis % 1000;
        char buffer[16];
        sprintf(buffer, "%d.%02d", seconds, millisecs / 10);
        TFTscreen.stroke(255, 255, 255);
        TFTscreen.setTextSize(2);
        TFTscreen.text(buffer, SCREEN_WIDTH - 80, SCREEN_HEIGHT - 40);
        state = 3;
        break;
    }
  }
  if (reset) {
    reset = false;
    startMillis = millis();
    state = 1;
  }
  uint32_t currentMillis = millis();
  if (currentMillis - prevMillis >= 1000) {
    prevMillis = currentMillis;
    drawClock();
  }
}

最后，还需要定义定时器的中断处理函数`timerHandler()`，用于更新秒针位置。代码如下：

void timerHandler() {
  static uint16_t prevSeconds = 0;
  uint32_t elapsedMillis = millis() - startMillis;
  uint16_t seconds = elapsedMillis / 1000;
  if (seconds != prevSeconds) {
    TFTscreen.stroke(0, 0, 0);
    TFTscreen.line(SCREEN_WIDTH / 2, SCREEN_HEIGHT / 2, 
                    SCREEN_WIDTH / 2 + SEC_LENGTH * sin((seconds - 15) * PI / 30),
                    SCREEN_HEIGHT / 2 - SEC_LENGTH * cos((seconds - 15) * PI / 30));
    TFTscreen.stroke(255, 0, 0);
    TFTscreen.line(SCREEN_WIDTH / 2, SCREEN_HEIGHT / 2, 
                    SCREEN_WIDTH / 2 + SEC_LENGTH * sin((seconds - 15) * PI / 30),
                    SCREEN_HEIGHT / 2 - SEC_LENGTH * cos((seconds - 15) * PI / 30));
    prevSeconds = seconds;
  }
}

完整的代码如下：

#include <stdint.h>
#include <TFTv2.h>
#include <SPI.h>
#include <TimerOne.h>

#define SCREEN_WIDTH  320
#define SCREEN_HEIGHT 240
#define SCALE_RADIUS  80
#define NUM_RADIUS    60
#define SEC_LENGTH    70
#define BUTTON_PIN    2

TFT TFTscreen = TFT(SCREEN_WIDTH, SCREEN_HEIGHT);
volatile bool buttonPressed = false;
volatile bool reset = false;
volatile uint32_t startMillis = 0;
volatile uint32_t pauseMillis = 0;

void interruptHandler() {
  buttonPressed = true;
}

void timerHandler() {
  static uint16_t prevSeconds = 0;
  uint32_t elapsedMillis = millis() - startMillis;
  uint16_t seconds = elapsedMillis / 1000;
  if (seconds != prevSeconds) {
    TFTscreen.stroke(0, 0, 0);
    TFTscreen.line(SCREEN_WIDTH / 2, SCREEN_HEIGHT / 2, 
                    SCREEN_WIDTH / 2 + SEC_LENGTH * sin((seconds - 15) * PI / 30),
                    SCREEN_HEIGHT / 2 - SEC_LENGTH * cos((seconds - 15) * PI / 30));
    TFTscreen.stroke(255, 0, 0);
    TFTscreen.line(SCREEN_WIDTH / 2, SCREEN_HEIGHT / 2, 
                    SCREEN_WIDTH / 2 + SEC_LENGTH * sin((seconds - 15) * PI / 30),
                    SCREEN_HEIGHT / 2 - SEC_LENGTH * cos((seconds - 15) * PI / 30));
    prevSeconds = seconds;
  }
}

void drawClock() {
  TFTscreen.background(255, 255, 255);
  TFTscreen.stroke(0, 0, 0);
  TFTscreen.fill(255, 255, 255);
  TFTscreen.circle(SCREEN_WIDTH / 2, SCREEN_HEIGHT / 2, SCALE_RADIUS);
  TFTscreen.setTextSize(3);
  for (uint8_t i = 0; i < 12; i++) {
    uint16_t x = SCREEN_WIDTH / 2 + SCALE_RADIUS * sin(i * PI / 6);
    uint16_t y = SCREEN_HEIGHT / 2 - SCALE_RADIUS * cos(i * PI / 6);
    TFTscreen.text(String(i + 1), x - 8, y - 16);
    TFTscreen.line(x, y, x + NUM_RADIUS * sin(i * PI / 6), y - NUM_RADIUS * cos(i * PI / 6));
  }
}

void setup() {
  TFTscreen.begin();
  SPI.begin();
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(BUTTON_PIN), interruptHandler, FALLING);
  Timer1.initialize(10000);
  Timer1.attachInterrupt(timerHandler);
}

void loop() {
  static uint8_t state = 0;
  static uint32_t prevMillis = 0;
  if (buttonPressed) {
    buttonPressed = false;
    switch (state) {
      case 0:
        startMillis = millis();
        state = 1;
        break;
      case 1:
        pauseMillis = millis();
        state = 2;
        break;
      case 2:
        startMillis += millis() - pauseMillis;
        state = 1;
        break;
      case 3:
        pauseMillis = millis();
        state = 4;
        break;
      case 4:
        uint32_t elapsedMillis = pauseMillis - startMillis;
        uint16_t seconds = elapsedMillis / 1000;
        uint16_t millisecs = elapsedMillis % 1000;
        char buffer[16];
        sprintf(buffer, "%d.%02d", seconds, millisecs / 10);
        TFTscreen.stroke(255, 255, 255);
        TFTscreen.setTextSize(2);
        TFTscreen.text(buffer, SCREEN_WIDTH - 80, SCREEN_HEIGHT - 40);
        state = 3;
        break;
    }
  }
  if (reset) {
    reset = false;
    startMillis = millis();
    state = 1;
  }
  uint32_t currentMillis = millis();
  if (currentMillis - prevMillis >= 1000) {
    prevMillis = currentMillis;
    drawClock();
  }
}