我有以下草图，并且 numTicks 变量没有增加，草图可以很好地编译到 Arduino，但无论出于何种原因，变量“numTicks”没有增加。
/*
* 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());
}
}