Monitoring Power Down Using Arduino UNO and ZMPT101B - arduino

Question

I am in the process of implementing power down alerting system suing Arduino UNO and ZMPT101B Single phase relay.
My code as follows,
#include <Filters.h> //Easy library to do the calculations
float testFrequency = 50; // test signal frequency (Hz)
float windowLength = 40.0/testFrequency; // how long to average the signal, for statistist
int Sensor = 0; //Sensor analog input, here it's A0
float intercept = -0.04; // to be adjusted based on calibration testing
float slope = 0.0405; // to be adjusted based on calibration testing
float current_Volts; // Voltage
unsigned long printPeriod = 1000; //Refresh rate
unsigned long previousMillis = 0;
void setup() {
Serial.begin( 9600 ); // start the serial port
}
void loop() {
RunningStatistics inputStats; //Easy life lines, actual calculation of the RMS requires a load of coding
inputStats.setWindowSecs( windowLength );
while( true ) {
Sensor = analogRead(A0); // read the analog in value:
inputStats.input(Sensor); // log to Stats function
if((unsigned long)(millis() - previousMillis) >= printPeriod) {
previousMillis = millis(); // update time every second
Serial.print( "\n" );
current_Volts = intercept + slope * inputStats.sigma(); //Calibartions for offset and amplitude
current_Volts= current_Volts*(40.3231); //Further calibrations for the amplitude
Serial.print( "\tVoltage: " );
Serial.print( current_Volts ); //Calculation and Value display is done the rest is if you're using an OLED display
if (current_Volts <229) {
test_loop();
}
}
}
}
void test_loop(){
Serial.print( "Warning!! Server Room Power Down" );
delay(1000);
}
I am getting the correct voltage reading.
But when power down it says power down.
But when power got up it still shows power down with older reading.
I think the reason for this because my code unable to stop the loop.
And if I remove the delay (1000) in test_loop function it works,
But my intention to use this sms alerting system and for that I need this delay to stop unnecessary alerts.
My code for SMS Alerting,
Serial.print( "\tVoltage: " );
Serial.print( current_Volts ); //Calculation and Value display is done the rest is if you're using an OLED display
if (current_Volts <229) {
SendMessage();
}
void test_loop() {
mySerial.println("AT+CMGF=1"); //Sets the GSM Module in Text Mode
delay(1000); // Delay of 1000 milli seconds or 1 second
mySerial.println("AT+CMGS=\"xxxxxxxxx\"\r"); // Replace x with mobile number
delay(1000);
mySerial.println("Warning!! Server Room Power Down");
delay(100);
mySerial.println((char)26);// ASCII code of CTRL+Z
delay(150000);
mySerial.println("AT+CMGD=2");
}
This code works for the very first outage but after power up also it send power down.
First code of Serial.print is used fro debugging.
Kindly help.

Answer 1

Thanks to the Arduino Forum User: leongjerland
I was able to fix the issue.
The code as below,
if (current_Volts < 229) {
if (!alarmSent) {
test_loop();
alarmSent = true;
}
}
else {
alarmSent = false;
}
}

Answer 2

Try seeing with a voltmeter what the voltage is at the A0 pin in the good and the bad case. You don't need to decode the voltage, just see if it the sensor is working as you expect.