Working a temprature sensor (LM35) with a GSM module (Sim800L) - arduino

Question

I have a temperature sensor set up working with an LCD and a stick to adjust the brightness. I now want the temperature sensor to send a text whenever it reaches a certain temperature. Can somebody please help.
The GSM unit i have is the SIM800L
below is what I have so far :
#include<LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
const int sensor=A1; // Assigning Analog Pin A1 to variable 'sensor'
float tempc; //variable to store temperature in degree Celsius
float tempf; //variable to store temperature in Fahrenheit
float vout; //temporary variable to hold sensor reading
void setup()
{
pinMode(sensor,INPUT); // Configuring pin A1 as INPUT Pin
Serial.begin(9600);
lcd.begin(16,2);
delay(500);
}
void loop()
{
vout=analogRead(sensor);
vout=(vout*500)/1023;
tempc=vout; // Storing value in degrees Celsius
tempf=(vout*1.8)+32; // Converting Temperature value from degrees Celsius to Fahrenheit
lcd.setCursor(0,0);
lcd.print("DegreeC= ");
lcd.print(tempc);
lcd.setCursor(0,1);
lcd.print("Fahrenheit=");
lcd.print(tempf);
delay(1000); //Delay of 1 second for ease of viewing in serial monitor
}

Answer 1

you could use the library Fona to send SMS with a Sim800L
to send a message you use the command -> fona.sendSMS(sendto, message)
#include <SoftwareSerial.h>
#include "Adafruit_FONA.h"
//This part declares that the RX, TX and RST pins of the SIM800L must be connected
//to pin 2, 3 and 4 of the Arduino.
#define FONA_RX 2
#define FONA_TX 3
#define FONA_RST 4
SoftwareSerial fonaSS = SoftwareSerial(FONA_RX, FONA_TX);
Adafruit_FONA fona = Adafruit_FONA(FONA_RST);
void setup() {
while (!Serial);
Serial.begin(115200);
Serial.println(F("FONA basic test"));
Serial.println(F("Initializing....(May take 3 seconds)"));
fonaSS.begin(9600);
if (!fona.begin(fonaSS)) {
Serial.println(F("Couldn't find FONA"));
while (1);
}
Serial.println(F("FONA is OK"));
char sendto[21], message[141];
:
:
//initialize sendto and message
:
:
if (!fona.sendSMS(sendto, message)) {
Serial.println(F("error"));
} else {
Serial.println(F("sent!"));
}
}
to adapt the program to your case: i have put some lines of codes from setup to loop (easy to understant sendto and message definitions in loop now)
#include <SoftwareSerial.h>
#include "Adafruit_FONA.h"
//This part declares that the RX, TX and RST pins of the SIM800L must be connected
//to pin 2, 3 and 4 of the Arduino.
#define FONA_RX 2
#define FONA_TX 3
#define FONA_RST 4
SoftwareSerial fonaSS = SoftwareSerial(FONA_RX, FONA_TX);
Adafruit_FONA fona = Adafruit_FONA(FONA_RST);
void setup() {
fonaSS.begin(9600);
// you initialisation code
}
void loop()
{
vout=analogRead(sensor);
vout=(vout*500)/1023;
tempc=vout; // Storing value in degrees Celsius
tempf=(vout*1.8)+32; // Converting Temperature value from degrees Celsius to Fahrenheit
lcd.setCursor(0,0);
lcd.print("DegreeC= ");
lcd.print(tempc);
lcd.setCursor(0,1);
lcd.print("Fahrenheit=");
lcd.print(tempf);
delay(1000); //Delay of 1 second for ease of viewing in serial monitor
if (tempc > 30.0) {
SendSms();
}
}
void SendSms() {
char sendto[] = "[phone]"; //put the desired destination phone number for sms here
char message[141];
sprintf(message, "Alert TEMP is %.2f", tempc);// limit to 140
//sends the message via SMS
if (!fona.sendSMS(sendto, message)) {
Serial.println(F("error"));
} else {
Serial.println(F("sent!"));
}
}
another way to send sms
you could test the hayes command: for example
void sendsms(){
Serial.println("Sending text message...");
fonaSS.print("AT+CMGF=1\r"); // SMS MODE
delay(100);
// phone number
fonaSS.print("AT+CMGS=\"[phone]\"\r"); //indicate your phone number
delay(100);
// message here
fonaSS.print("Message test \r");
// CTR+Z in mode ASCII, to indicate the end of message
fonaSS.print(char(26));
delay(100);
fonaSS.println();
Serial.println("Text send");
}

Answer 2

#include <SoftwareSerial.h>
#include "Adafruit_FONA.h"
//This part declares that the RX, TX and RST pins of the SIM800L must be connected
//to pin 2, 3 and 4 of the Arduino.
#define FONA_RX 2
#define FONA_TX 3
#define FONA_RST 4
SoftwareSerial fonaSS = SoftwareSerial(FONA_TX, FONA_RX);
Adafruit_FONA fona = Adafruit_FONA(FONA_RST);
void setup() {
// you initialisation code
}
void loop()
{
vout=analogRead(sensor);
vout=(vout*500)/1023;
tempc=vout; // Storing value in degrees Celsius
tempf=(vout*1.8)+32; // Converting Temperature value from degrees Celsius to Fahrenheit
lcd.setCursor(0,0);
lcd.print("DegreeC= ");
lcd.print(tempc);
lcd.setCursor(0,1);
lcd.print("Fahrenheit=");
lcd.print(tempf);
delay(1000); //Delay of 1 second for ease of viewing in serial monitor
if (tempc > 30.0) {
SendSms();
}
}
void SendSms() {
char sendto[] = "[phone]"; //put the desired destination phone number for sms here
char message[141];
sprintf(message, "Alert TEMP is %.2f", tempc);// limit to 140
//sends the message via SMS
if (!fona.sendSMS(sendto, message)) {
Serial.println(F("error"));
} else {
Serial.println(F("sent!"));
}
}