Question

我有以下草图，并且numTicks变量没有递增，草图编译为Arduino，但无论出于何种原因，变量“numTicks”没有递增。

/*
 * kegboard-clone-4-KegCop
 * This code is public domain
 *
 * This sketch sends a receives a multibyte String from the iPhone
 * and performs functions on it.
 *
 * This Arduino sketch is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU Public License
 * along with this sketch.  If not, see <http://www.gnu.org/licenses/>.
 * 
 * Examples:
 * http://arduino.cc/en/Tutorial/SerialEvent
 * http://arduino.cc/en/Serial/read
 * http://stackoverflow.com/questions/16532586/arduino-sketch-that-responds-to-certain-commands-how-is-it-done/
 * http://davebmiller.wordpress.com/2011/01/18/arduino-flowmeter/
 * http://forum.arduino.cc/index.php?topic=52003.0
 * http://arduino.cc/en/Reference/AttachInterrupt
 * https://github.com/just-kile/Zapfmaster2000/blob/master/src/zapfmaster2000-zapfkit-avr/draftkitAVR.ino
 *
 * TODO:
 * - eventually get code working with the SF800 flow sensor / flowmeter
 *
 */

// flow_A LED
int led = 4;

// relay_A
const int RELAY_A = A0;

// string / serial event variables
String inputString = ""; // a string to hold incoming data
boolean stringComplete = false; // whether the string is complete
boolean valve_open = false;

// FLOWMETER SHIT
// flowmeter 0 pulse (input) = digital pin 2
// https://github.com/Kegbot/kegboard/blob/master/arduino/kegboard/kegboard_config.h
// which pin to use for reading the sensor? kegboard-mini shield has digital pin 2 allocated
// the SF800 outputs 5400 pulses per litre
// The hall-effect flow sensor (SF800) outputs approximately 5400 pulses per second per litre/minute of flow
// SF800 default (5400 ticks/Liter == 5.4 ticks/mL == 1/5.4 mL/tick)
int flowmeterInterrupt = 0;  // changed from byte
int flowmeterPin = 2;        // changed from byte
int flowmeterPinState = 0;   // variable for storing state of sensor pin
// read RPM
int rpmcount = 0;
int rpm = 0;
unsigned long lastmillis = 0; 

// NEW GLOBALS - 29JUL13
// initial ticks on flow meter
volatile unsigned int numTicks = 0;
// interval for flow meter frequency
int interval = 250;
volatile long previousMillis = 0;

void setup() {
  // initialize serial
//  Serial.flush(); // flush the serial buffer on setup.
  Serial.begin(115200); // open serial port, sets data rate to 9600bps
  Serial.println("Power on test");
  inputString.reserve(200);
  valve_open = false;

  // relay for solenoid cut off valve
  pinMode(RELAY_A, OUTPUT);

  // flowmeter shit
  pinMode(flowmeterPin, INPUT);
  digitalWrite(flowmeterPin, HIGH); // Need to set these HIGH so they won't just tick away

  // The Hall-effect sensor is connected to pin 2 which uses interrupt 0.
  // Configured to trigger on a RISING state change (transition from HIGH
  // state to LOW state)
  attachInterrupt(flowmeterInterrupt, count, RISING);
}

void open_valve() {
  digitalWrite(RELAY_A, HIGH); // turn RELAY_A on
  valve_open = true;
}

void close_valve() {
  digitalWrite(RELAY_A, LOW); // turn RELAY_A off
  valve_open = false;
}

void flow_A_blink() {
  digitalWrite(led, HIGH); // turn the LED on (HIGH is the voltage level)
  delay(1000);              // wait for one second
  digitalWrite(led, LOW);   // turn the LED off by making the voltage LOW
  delay(1000);              // wait for a second
}

void flow_A_blink_stop() {
  digitalWrite(led, LOW);
}

void flow_A_on() {
  digitalWrite(led, HIGH); // turn the LED on (HIGH is the voltage level)
}

void flow_A_off() {
  digitalWrite(led, LOW);   // turn the LED off by making the voltage LOW
}  

// flowmeter shit
void getFlow4() {
//  Serial.println("im here");
//  Serial.println(sensorPin);

  flowmeterPinState = digitalRead(flowmeterPin);

//  Serial.println(sensorPinState);

  volatile unsigned long currentMillis = millis();
  // if the predefined interval has passed
  if(currentMillis - previousMillis > interval) { // Uptade every 1/4 second, this will be equal to reading frecuency (Hz).

    // disconnect flow meter from interrupt
    detachInterrupt(flowmeterInterrupt); // Disable interrupt when calculating
    // check, whether any flow was detected
    if (numTicks >= 0) {
      // start message to computer with tick message symbol
      Serial.print("Ticks:");
      // send amount of ticks for last interval
      Serial.print(numTicks);
    }
    // clean buffer
    Serial.flush();
    // reset amount of ticks
    numTicks = 0;
    // set new start value for interval counter
    previousMillis = currentMillis;
    // reattach interrupt
    attachInterrupt(flowmeterInterrupt, count, RISING);
  }


  if(flowmeterPinState == LOW) {
    flow_A_off();
//    Serial.println("don't blink");
  }
  if(flowmeterPinState == HIGH) {
    flow_A_on();
//    Serial.println("blink damnit");
  }

  if(stringComplete) {
    if(inputString.equals("{close_valve}\n")) {
      //      Serial.println("close vavle.");
      close_valve();
    }
    return;
  }
}
// flow meter interrupt function
void count(){
  numTicks++;
} 

/*
 * Main program loop, runs over and over repeatedly
 */

void loop() {
  if(stringComplete) {
//    Serial.println(inputString);

    if(inputString.equals("{open_valve}\n")) {
//      Serial.println("inputString equates :)");
      open_valve();
    }

    if(inputString.equals("{close_valve}\n")) {
      //      Serial.println("close vavle.");
      close_valve();
    }

  if(valve_open) {
//    Serial.println("valve_open = true");
    inputString = "";
    stringComplete = false;
    while(numTicks <= 1000) {
      getFlow4();
    }
  }

  // clear the string:
  inputString = "";
  stringComplete = false;
  }
//Serial.println("over and over");
}

/*
 SerialEvent occurs whenever a new data comes in the
 hardware serial RX.  This routine is run between each
 time loop() runs, so using delay inside loop can delay
 response.  Multiple bytes of data may be available.
 */

void serialEvent() {
  while(Serial.available()) {
    // get the new byte:
    char inChar = (char)Serial.read();
    // add it to the inputString:
    inputString += inChar;
    // if the incoming character is a newline, set a flag
    // so the main loop can do something about it:
    if (inChar == '\n') {
      stringComplete = true;
    }
    // Serial.println(inputString.length());
  }
}

Answer 1

numTicks变量未更改的原因可能是由于中断未触发。你应该在count（）中加一个断点来确认这一点。然后你需要找出中断没有触发的原因，但这是另一个问题。

Answer 2

对不起我之前的回答。我没有完全理解这个问题。

首先，您使用的是Arduino UNO，如果是这样，请检查标记为数字引脚2的板引脚，该引脚映射为“int.0”并确保流量计的中断线连接到该引脚。（见：http://arduino.cc/en/Reference/AttachInterrupt）。

根据上面的Chris评论，count（）例程是中断驱动的代码，它似乎编码正确：numTicks被定义为volatile;和count（）不会发出I / O命令，如printf;并且它不会返回任何值。

您提供的代码示例不会隔离或突出显示问题。我会写一个测试草图，这只是一个“打开”传感器，然后从流量计检测中断并从主循环报告回控制台的简单实现。如果您可以从流量计中获取检测到一个中断的代码，则可以在一秒内添加更多代码来报告中断次数，然后是1/2秒等。

最后，在您提供的代码中，您有片段：

    if(valve_open) {
         //    Serial.println("valve_open = true");
         inputString = "";
         stringComplete = false;
         while(numTicks <= 1000) {
            getFlow4();
         }
    }

由于numTicks由中断例程计数递增，因此除非实现某种序列化，否则我不会测试它。 getFlow4（）分离中断，这是序列化访问numTicks的一种方法。注意。理论上，代码可以在没有序列化的情况下更新numTicks，但返回的任何值都不一定准确，因为中断可能已经触发并增加了numTicks。

您的应用程序似乎有兴趣知道每秒的滴答数？在这种情况下，您不需要在停止中断之前测试numTicks。您可能需要的只是代码，每秒检查一次numTicks，如果您可以使用丢弃计数，则将numTicks清零，甚至不会分离中断。但是，采样numTicks更像是轮询，这是中断试图避免的。

因此，由于代码跟踪间隔，然后将间隔除以numTicks以获得Hz值，并且不会将numTicks归零或重置间隔，直到它们接近翻转为止。

Answer 3

代码最终正常工作，来自流量计的连接存在硬件问题（＆gt;。＆gt;）

Answer 4

您实际上从未调用count()方法。您应该将numTicks++;插入要增加计数的代码（推荐方式），或者调用您希望增加计数的count()方法。这里count()方法只是定义而不是被调用，但是在代码中增加计数器会更有意义，因为这是你定义的方法所做的唯一事情。

numTicks变量不递增

4 个答案: