Arduino receive response from SIM800H to AT+CCLK? command

Question

I've been trying to make a program that interacts with SIM800H trough AT commands. It worked with the String class, but it was full of "memory leaks" and after a few hours it just hanged. Then I tried to write it again with char arrays, but for some reason I couldn't get it to work properly.

Can someone suggest me a correction to my program and also a way to get char by char with loop and Serial.read();? Serial in this case (Arduino Leonardo) is the USB port and Serial1 is the port to the modem.

Here is my code:

const long interval = 2000;
static long currentMillis;
char wherecclk = 0; // To determine where is the + in +CCLK in the char array
char serialdata[256] = ""; // Array to store the chars before parsing
char rtcy1[3]; // Current year Format: yy0円
char rtcm1[3]; // Current month Format: mm0円
char rtcd1[3]; // Current day Format: dd0円
char rtch1[3]; // Current hour Format: hh0円
char rtcmm1[3]; // Current minute Format: mm0円
char rtcs1[3]; // Current second Format: ss0円
int rdpos = 0;
void setup() {
 Serial.begin(9600); // USB to Computer
 Serial1.begin(9600); // UART to Modem
 Serial1.print("ATE0\r"); // Disable echo
}
void loop() {
 wherecclk = 0;
 if (Serial1.available () > 0) { // when something comes on real serial
 strcpy(serialdata, "OK\n\n+CCLK: \"04/01/01,01:35:31+00\"\n\nOK\n"); // This is a real sample of the response coming from the modem emulated
 while (rdpos < 256) { // loop timeout: 256 bytes
 if (serialdata[rdpos] == '+') {
 break; // We have reached the first + char. Stop incrementing it
 }
 rdpos++;
 }
 if (serialdata[rdpos + 1] == 'C' && serialdata[rdpos + 2] == 'C' && serialdata[rdpos + 3] == 'L' && serialdata[rdpos + 4] == 'K') { // If the serial command mathes +CCLK save its position
 wherecclk = rdpos;
 }
 rdpos = 0;
 if (wherecclk != 0) {
 rtcy1[0] = serialdata[wherecclk + 8]; // getting first char with its offset
 rtcy1[1] = serialdata[wherecclk + 9];
 rtcy1[2] = '0円';
 rtcm1[0] = serialdata[wherecclk + 11];
 rtcm1[1] = serialdata[wherecclk + 12];
 rtcm1[2] = '0円';
 rtcd1[0] = serialdata[wherecclk + 14];
 rtcd1[1] = serialdata[wherecclk + 16];
 rtcd1[2] = '0円';
 rtch1[0] = serialdata[wherecclk + 17];
 rtch1[1] = serialdata[wherecclk + 18];
 rtch1[2] = '0円';
 rtcm1[0] = serialdata[wherecclk + 20];
 rtcm1[1] = serialdata[wherecclk + 21];
 rtcm1[2] = '0円';
 rtcs1[0] = serialdata[wherecclk + 23];
 rtcs1[1] = serialdata[wherecclk + 24];
 rtcs1[2] = '0円';
 }
 }
 if (millis() - currentMillis >= interval) { // This is done every second
 Serial1.print("AT+CCLK?\r"); // ask for the time
 // delay(50);
 Serial.println("");
 Serial.println("=====");
 Serial.println(millis());
 Serial.println("YEAR: ");
 Serial.print(rtcy1[0]);
 Serial.println(rtcy1[1]);
 Serial.println("MONTH: ");
 Serial.print(rtcm1[0]);
 Serial.println(rtcm1[1]);
 Serial.println("DAY: ");
 Serial.print(rtcd1[0]);
 Serial.println(rtcd1[1]);
 Serial.println("HOUR: ");
 Serial.print(rtch1[0]);
 Serial.println(rtch1[1]);
 Serial.println("MINUTE: ");
 Serial.print(rtcmm1[0]);
 Serial.println(rtcmm1[1]);
 Serial.println("SECOND: ");
 Serial.print(rtcs1[0]);
 Serial.println(rtcs1[1]);
 currentMillis = millis();
 }
}

Here is the output (a screenshot, because serial monitor doesn't give me full code):

serial monitor

Answer 1

You declare your variables for month and minute differently (rtcm1[3] vs rtcmm1[3]), but you load rtcm1 with month, and then a few lines later, with minutes.

• A. Somov: Silly me! I guess I overlooked the typo and thought it's some other error

Answer 2

Here's the final code in case someone needs it:

const long interval = 1000;
static long currentMillis;
char wherecclk = 0; //To determine where is the + in +CCLK in the char array
char serialdata[256] = ""; //Array to store the chars before parsing
char rtcy1[3]; //Current year Format: yy0円
char rtcm1[3]; //Current month Format: mm0円
char rtcd1[3]; //Current day Format: dd0円
char rtch1[3]; //Current hour Format: hh0円
char rtcmm1[3]; //Current minute Format: mm0円
char rtcs1[3]; //Current second Format: ss0円
int rdpos = 0;
int pointingfinger = 0;
void setup() {
 Serial.begin(9600); //USB to Computer
 Serial1.begin(9600); //UART to Modem
 Serial1.print("ATE0\r"); //Disable echo
}
void loop() {
 if (Serial1.available () > 0) { //when something comes on real serial
 rdpos = 0;
 wherecclk = 0;
 if (pointingfinger == 255) {
 pointingfinger = 0;
 }
 serialdata[pointingfinger] = Serial1.read();
 while (rdpos < 256) //loop timeout: 256 bytes
 {
 if (serialdata[rdpos] == '+') {
 break; //We have reached the first + char. Stop incrementing it
 }
 rdpos++;
 }
 if (serialdata[rdpos + 1] == 'C' && serialdata[rdpos + 2] == 'C' && serialdata[rdpos + 3] == 'L' && serialdata[rdpos + 4] == 'K') { //If the serial command mathes +CCLK save its position
 wherecclk = rdpos;
 }
 pointingfinger++;
 }
 if (millis() - currentMillis >= interval) //This is done every second
 {
 pointingfinger = 0;
 //Serial.println("=========");
 //Serial.println(serialdata);
 //Serial.println("=========");
 if (wherecclk != 0) {
 rtcy1[0] = serialdata[wherecclk + 8]; //getting first char with its offset
 rtcy1[1] = serialdata[wherecclk + 9];
 rtcy1[2] = '0円';
 rtcm1[0] = serialdata[wherecclk + 11];
 rtcm1[1] = serialdata[wherecclk + 12];
 rtcm1[2] = '0円';
 rtcd1[0] = serialdata[wherecclk + 14];
 rtcd1[1] = serialdata[wherecclk + 15];
 rtcd1[2] = '0円';
 rtch1[0] = serialdata[wherecclk + 17];
 rtch1[1] = serialdata[wherecclk + 18];
 rtch1[2] = '0円';
 rtcmm1[0] = serialdata[wherecclk + 20];
 rtcmm1[1] = serialdata[wherecclk + 21];
 rtcmm1[2] = '0円';
 rtcs1[0] = serialdata[wherecclk + 23];
 rtcs1[1] = serialdata[wherecclk + 24];
 rtcs1[2] = '0円';
 }
 Serial1.print("AT+CCLK?\r"); //ask for the time
 //delay(50);
 Serial.println("");
 Serial.println("=====");
 Serial.println(millis());
 Serial.println("YEAR: ");
 Serial.print(rtcy1[0]);
 Serial.println(rtcy1[1]);
 Serial.println("MONTH: ");
 Serial.print(rtcm1[0]);
 Serial.println(rtcm1[1]);
 Serial.println("DAY: ");
 Serial.print(rtcd1[0]);
 Serial.println(rtcd1[1]);
 Serial.println("HOUR: ");
 Serial.print(rtch1[0]);
 Serial.println(rtch1[1]);
 Serial.println("MINUTE: ");
 Serial.print(rtcmm1[0]);
 Serial.println(rtcmm1[1]);
 Serial.println("SECOND: ");
 Serial.print(rtcs1[0]);
 Serial.println(rtcs1[1]);
 currentMillis = millis();
 }
}