Hello guys.
I am sending liquid data from arduino to ThingSpeak cloud. The problem I am facing that if I send data after the 'if' statement inside the loop, the data is sent but it is not entirely accurate and even when the sensor is not receiving any liquid, the last reading is continuously being sent which is problematic.
Can anyone tell me where should I use the data sending code to send the accurate readings?
The code is below:
#include "ThingSpeak.h"
//#define USE_WIFI101_SHIELD
#if defined(ARDUINO_AVR_YUN)
#include "YunClient.h"
YunClient client;
#else
#if defined(USE_WIFI101_SHIELD) || defined(ARDUINO_SAMD_MKR1000) || defined(ARDUINO_ARCH_ESP8266)
// Use WiFi
#ifdef ARDUINO_ARCH_ESP8266
#include <ESP8266WiFi.h>
#else
#include <SPI.h>
#include <WiFi101.h>
#endif
char ssid[] = "<>"; // your network SSID (name)
char pass[] = "<>"; // your network password
int status = WL_IDLE_STATUS;
WiFiClient client;
#elif defined(USE_ETHERNET_SHIELD)
// Use wired ethernet shield
#include <SPI.h>
#include <Ethernet.h>
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED};
EthernetClient client;
#endif
#endif
unsigned long myChannelNumber = ;
const char * myWriteAPIKey = "";
byte statusLed = 13;
byte sensorInterrupt = 0; // 0 = digital pin 2
byte sensorPin = 3;
// The hall-effect flow sensor outputs approximately 4.5 pulses per second per
// litre/minute of flow.
float calibrationFactor = 9.5;
volatile byte pulseCount;
float flowRate;
unsigned int flowMilliLitres;
unsigned long totalMilliLitres;
unsigned long oldTime;
void setup() {
#ifdef ARDUINO_AVR_YUN
Bridge.begin();
#else
#if defined(ARDUINO_ARCH_ESP8266) || defined(USE_WIFI101_SHIELD) || defined(ARDUINO_SAMD_MKR1000)
WiFi.begin(ssid, pass);
#else
Ethernet.begin(mac);
#endif
#endif
ThingSpeak.begin(client);
pinMode(statusLed, OUTPUT);
digitalWrite(statusLed, HIGH); // We have an active-low LED attached
pinMode(sensorPin, INPUT);
digitalWrite(sensorPin, HIGH);
pulseCount = 0;
flowRate = 0.0;
flowMilliLitres = 0;
totalMilliLitres = 0;
oldTime = 0;
// The Hall-effect sensor is connected to pin 2 which uses interrupt 0.
// Configured to trigger on a FALLING state change (transition from HIGH
// state to LOW state)
attachInterrupt(sensorInterrupt, pulseCounter, FALLING);
}
void loop() {
if((millis() - oldTime) > 1000) // Only process counters once per second
{
// Disable the interrupt while calculating flow rate and sending the value to
// the host
detachInterrupt(sensorInterrupt);
// Because this loop may not complete in exactly 1 second intervals we calculate
// the number of milliseconds that have passed since the last execution and use
// that to scale the output. We also apply the calibrationFactor to scale the output
// based on the number of pulses per second per units of measure (litres/minute in
// this case) coming from the sensor.
flowRate = ((1000.0 / (millis() - oldTime)) * pulseCount) / calibrationFactor;
// Note the time this processing pass was executed. Note that because we've
// disabled interrupts the millis() function won't actually be incrementing right
// at this point, but it will still return the value it was set to just before
// interrupts went away.
oldTime = millis();
// Divide the flow rate in litres/minute by 60 to determine how many litres have
// passed through the sensor in this 1 second interval, then multiply by 1000 to
// convert to millilitres.
flowMilliLitres = (flowRate / 60) * 1000;
// Add the millilitres passed in this second to the cumulative total
totalMilliLitres += flowMilliLitres;
unsigned int frac;
// Serial.print("Flow rate: ");
//Serial.print(int(flowRate)); // Print the integer part of the variable
//Serial.print("."); // Print the decimal point
// Determine the fractional part. The 10 multiplier gives us 1 decimal place.
frac = (flowRate - int(flowRate)) * 10;
ThingSpeak.writeField(myChannelNumber, 1, (long) totalMilliLitres, myWriteAPIKey);
delay(20000); // ThingSpeak will only accept updates every 15 seconds.
//Serial.print(frac, DEC) ; // Print the fractional part of the variable
//Serial.print("L/min");
// Print the number of litres flowed in this second
//Serial.print(" Current Liquid Flowing: "); // Output separator
//Serial.print(flowMilliLitres);
//Serial.print("mL/Sec");
// Print the cumulative total of litres flowed since starting
//Serial.print(" Output Liquid Quantity: "); // Output separator
//Serial.print(totalMilliLitres);
//Serial.println("mL");
pulseCount = 0;
// Enable the interrupt again now that we've finished sending output
attachInterrupt(sensorInterrupt, pulseCounter, FALLING);
ThingSpeak.writeField(myChannelNumber, 1, (long) totalMilliLitres, myWriteAPIKey);
delay(20000); // ThingSpeak will only accept updates every 15 seconds.
}
}
void pulseCounter()
{
// Increment the pulse counter
pulseCount++;
}
I am looking forward to your suggestions and help.
Thanks
Rushan