Can someone help identify what I am doing wrong in the following code:
I am attempting to read the flow data from a hall effect sensor. The sample code for the sensor runs fine until I added the code to log the date and time from the RTC (Chronodot). Sensor is on pin 2 and powered with 5V. Chronodot is powered with 3V from uno board. Chronodot SDA is connected to A4 and SCL is A5. Chronodot when run with a sample code works fine. Something is probably wrong with the way I am calling the interrupt.
Code: Select all
/**********************************************************
This is example code for using the Adafruit liquid flow meters.
Tested and works great with the Adafruit plastic and brass meters
------> http://www.adafruit.com/products/828
------> http://www.adafruit.com/products/833
Connect the red wire to +5V,
the black wire to common ground
and the yellow sensor wire to pin #2
Adafruit invests time and resources providing this open source code,
please support Adafruit and open-source hardware by purchasing
products from Adafruit!
Written by Limor Fried/Ladyada for Adafruit Industries.
BSD license, check license.txt for more information
All text above must be included in any redistribution
**********************************************************/
#include <Wire.h>
#include "RTClib.h" // Credit: Adafruit
volatile RTC_DS1307 RTC;
#include <SD.h>
File myFile;
String fileName = String("WaterMon.csv");
// which pin to use for reading the sensor? can use any pin!
#define FLOWSENSORPIN 2
// count how many pulses!
volatile uint16_t pulses = 0;
// track the state of the pulse pin
volatile uint8_t lastflowpinstate;
// you can try to keep time of how long it is between pulses
volatile uint32_t lastflowratetimer = 0;
// and use that to calculate a flow rate
volatile float flowrate;
// Interrupt is called once a millisecond, looks for any pulses from the sensor!
SIGNAL(TIMER0_COMPA_vect) {
uint8_t x = digitalRead(FLOWSENSORPIN);
if (x == lastflowpinstate) {
lastflowratetimer++;
return; // nothing changed!
}
if (x == HIGH) {
//low to high transition!
pulses++;
}
lastflowpinstate = x;
flowrate = 1000.0;
flowrate /= lastflowratetimer; // in hertz
lastflowratetimer = 0;
}
void useInterrupt(boolean v) {
if (v) {
// Timer0 is already used for millis() - we'll just interrupt somewhere
// in the middle and call the "Compare A" function above
OCR0A = 0xAF;
TIMSK0 |= _BV(OCIE0A);
} else {
// do not call the interrupt function COMPA anymore
TIMSK0 &= ~_BV(OCIE0A);
}
}
void setup() {
Serial.begin(115200);
Serial.print("Flow sensor test!");
//initialize SD card
pinMode(10, OUTPUT);
if (!SD.begin(4)) {
return;
}
myFile = SD.open("WaterMon.csv",FILE_WRITE);
if (myFile) {
myFile.println("Date, Time, Frequency, Pulses, Liters");
myFile.close();
}
else {
//do nothing
}
pinMode(FLOWSENSORPIN, INPUT);
digitalWrite(FLOWSENSORPIN, HIGH);
lastflowpinstate = digitalRead(FLOWSENSORPIN);
useInterrupt(true);
}
void loop() // run over and over again
{
// Get the current time
DateTime now = RTC.now();
// if a plastic sensor use the following calculation
// Sensor Frequency (Hz) = 7.5 * Q (Liters/min)
// Liters = Q * time elapsed (seconds) / 60 (seconds/minute)
// Liters = (Frequency (Pulses/second) / 7.5) * time elapsed (seconds) / 60
// Liters = Pulses / (7.5 * 60)
float liters = pulses;
liters /= 7.5;
liters /= 60.0;
// if a brass sensor use the following calculation
// float liters = pulses;
// liters /= 8.1;
// liters -= 6;
// liters /= 60.0;
myFile = SD.open("WaterMon.csv", FILE_WRITE);
if (myFile) {
myFile.print(now.year(),DEC); myFile.print('/'); myFile.print(now.month(), DEC); myFile.print('/'); myFile.print(now.day(), DEC);
myFile.print(",");
myFile.print(now.hour(), DEC); myFile.print(':'); myFile.print(now.minute(), DEC); myFile.print(':'); myFile.print(now.second(), DEC);
myFile.print(",");
myFile.print(flowrate);
myFile.print(",");
myFile.print(pulses, DEC);
myFile.print(",");
myFile.print(liters);
myFile.println(",");
myFile.close();
}
else{
//Do nothing
}
Serial.print("Current time: ");
Serial.print(now.year(), DEC);
Serial.print('/');
Serial.print(now.month(), DEC);
Serial.print('/');
Serial.print(now.day(), DEC);
Serial.print(' ');
Serial.print(now.hour(), DEC);
Serial.print(':');
Serial.print(now.minute(), DEC);
Serial.print(':');
Serial.print(now.second(), DEC);
Serial.println();
Serial.print("Freq: "); Serial.println(flowrate);
Serial.print("Pulses: "); Serial.println(pulses, DEC);
Serial.print(liters); Serial.println(" Liters");
delay(1000);
}
