Hi all
firstly i am a newbie, so please do not flame me for not knowing as much as you do !
in my own field i wouldnt do it to you,
I have tried multiple ways and spent the last 2days trying to get a very simple operation (part of the code) to occur, read the RPM every loop,
i have tried everything i can think of replaced it with other code.. but in the end the same
also theier weird characters in some of my lcd.prints ..
Any help would be gretaly appreciated 
float current=0;
float voltage=0;
float power=0;
float acpower=0;
float value=0;
float kw=0;
float getVPP();
const int sensorIn = A3;
int mVperAmp = 66; // change this value for calibration - use 100 for 20A Module and 66 for 30A Module
float rev=0;
int rpm=0;
int oldtime=0;
int time;
float torque=0;
float torque1=0;
void isr() //interrupt service routine, only in pin number 2 or pin number 3
{
rev++;
}
void setup()
{
pinMode(A0,INPUT);
pinMode(A1,INPUT);
pinMode(A3,INPUT);
// initialize the LCD
lcd.begin();
// Turn on the blacklight and print a message.
lcd.backlight();
lcd.print("MY POWER!");
delay(5000);
lcd.clear();
lcd.setCursor(0,0);
lcd.print("Motor POWERED"); //printing on LCD
lcd.setCursor(0,1); //sets the position where to print
lcd.print(" GENERATOR");
delay(5000);
lcd.clear();
Serial.begin(9600); // To see the values on the serial monitor
attachInterrupt(0,isr,RISING); //attaching the interrupt
}
void loop()
// taking the average for stable readings
{
delay(1000);
{
detachInterrupt(0);
}
time=millis()-oldtime; //finding total time for one rev
rpm=(rev/time)*60000; //calculating the rpm
oldtime=millis();
rev=0;
current=current + analogRead(A0);
voltage=voltage + analogRead(A1);
current=(current/20); current=current * 0.07595 * 5.0; // calibration value,to be changed according to components used
voltage=(voltage/20); voltage=voltage* 0.2075 * 5.0; // calibration value,to be changed according to components used
power= voltage*current;
Voltage1 = getVPP();
VRMS = (Voltage1/2.0) *0.707; //root 2 is 0.707
AmpsRMS = (VRMS * 1000)/mVperAmp;
InputPower = 240 * AmpsRMS;
kw = (240 / 1000);
torque1 = rpm * 9.5488;
torque = kw / torque1;
lcd.setCursor(4,0);
lcd.print("RPM TESTER"); //printing on LCD
lcd.setCursor(5,1); //sets the position where to print
lcd.print(rpm);
lcd.println(" RPM");
delay(6000);
lcd.setCursor(0,0);
lcd.print("VOLTS: ");
lcd.print(voltage);
lcd.println(" VDC");
lcd.setCursor(0,1);
lcd.print("AMPS: ");
lcd.print(current);
lcd.println("A ");
delay(4000);
lcd.clear();
lcd.setCursor(1,0);
lcd.print("OUTPUT POWER:");
lcd.setCursor(3,1);
lcd.print(power);
lcd.println("W" );
delay(2000);
lcd.clear();
lcd.setCursor(0, 0);
lcd.print("Input = 240VAC");
lcd.setCursor(2, 1);
lcd.println("Amps" );
lcd.print( AmpsRMS);
delay(4000);
lcd.clear();
lcd.setCursor(2, 0);
lcd.println("INPUT POWER" );
lcd.setCursor(2, 1);
lcd.print(InputPower);
lcd.println("Watts" );
delay(4000);
lcd.clear();
lcd.setCursor(2,0);
lcd.print("INPUT TORQUE:");
lcd.setCursor(3,1);
lcd.print(torque);
lcd.println("Nm" );
delay(2000);
lcd.clear();
}
float getVPP()
{
float result;
int readValue; //value read from the sensor
int maxValue = 0; // store max value here
int minValue = 1024; // store min value here
uint32_t start_time = millis();
while((millis()-start_time) < 2000) //sample for 2 Sec
{
readValue = analogRead(sensorIn);
// see if you have a new maxValue
if (readValue > maxValue)
{
/*record the maximum sensor value*/
maxValue = readValue;
}
if (readValue < minValue)
{
/*record the minimum sensor value*/
minValue = readValue;
}
}
// Subtract min from max
result = ((maxValue - minValue) * 5.0)/1024.0;
return result;
}
