Hello there, I need some help with coding the ESP8266 Node MCU to send data from Arduino Ide to MIT app inventor. I'm doing a project where is sends real time data value from PH sensor and Turbididty sensor to MIT app inventor. I've already done with the arduino and MIT app coding but i had problem coding the esp 8266. i just need some reference on how to code it even better if you guys could come up with the coding. it is for my final year project. Have a good day guys.
This is the code for Arduino :
#include <Wire.h>
#define pHPin A1 //pH meter Analog output to Arduino Analog Input 2
#define Offset 0.30 //deviation compensate
#define LED 13
#define samplingInterval 20
#define printInterval 800
#define ArrayLenth 40 //times of collection
int pHArray[ArrayLenth]; //Store the average value of the sensor feedback
int pHArrayIndex = 0;
int turbidityPin = A0;
float volt;
float ntu;
void setup()
{
Serial.begin(9600);
}
void loop()
{
volt = 0;
for(int i=0; i<1000; i++)
{
volt += ((float)analogRead(turbidityPin)/1023)*5 - 0.55;
}
volt = volt/1000;
volt = round_to_dp(volt,2);
if(volt < 2.5){
ntu = 3000;
}else{
ntu = -1120.4*square(volt)+5742.3*volt-4352.9;
}
Serial.print(volt);
Serial.print(" V\n");
Serial.print(ntu);
Serial.print(" NTU\n");
delay(10);
static unsigned long samplingTime = millis();
static unsigned long printTime = millis();
static float pHValue, voltage;
if (millis() - samplingTime > samplingInterval)
{
pHArray[pHArrayIndex++] = analogRead(pHPin);
if (pHArrayIndex == ArrayLenth)pHArrayIndex = 0;
voltage = avergearray(pHArray, ArrayLenth) * 5.0 / 1024 + 0.05;
pHValue = 3.5 * voltage + Offset;
samplingTime = millis();
}
if (millis() - printTime > printInterval) //Every 800 milliseconds, print a numerical, convert the state of the LED indicator
{
Serial.print("Voltage:");
Serial.print(voltage, 2);
Serial.print(" pH value: ");
Serial.println(pHValue, 2);
digitalWrite(LED, digitalRead(LED) ^ 1);
printTime = millis();
}
}
float round_to_dp( float in_value, int decimal_place )
{
float multiplier = powf( 10.0f, decimal_place );
in_value = roundf( in_value * multiplier ) / multiplier;
return in_value;
}
double avergearray(int* arr, int number)
{
int i;
int max, min;
double avg;
long amount = 0;
if (number <= 0)
{
Serial.println("Error number for the array to avraging!/n");
return 0;
}
if (number < 5) //less than 5, calculated directly statistics
{
for (i = 0; i < number; i++)
{
amount += arr[i];
}
avg = amount / number;
return avg;
}
else
{
if (arr[0] < arr[1])
{
min = arr[0]; max = arr[1];
}
else
{
min = arr[1]; max = arr[0];
}
for (i = 2; i < number; i++)
{
if (arr[i] < min)
{
amount += min; //arr<min
min = arr[i];
}
else
{
if (arr[i] > max)
{
amount += max; //arr>max
max = arr[i];
}
else
{
amount += arr[i]; //min<=arr<=max
}
}//if
}//for
avg = (double)amount / (number - 2);
}//if
return avg;
}
