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I'm trying to send a SMS and read data from Firebase with my NodeMCU Amica V2. The code works fine when I either only send a SMS or only read data from Firebase. However, when I combine this two codes SMS isn't sent. This is the error I get:

+ Connected.
+ Post an HTTP send SMS request.
+ Connection is closed.
+ Response:

31.0630+ Using fingerprint 'BC B0 1A 32 80 5D E6 E4 A2 29 66 2B 08 C8 E0 4C 45 29 3F D0'
+ Connecting to api.twilio.com
- Connection failed.
Last SSL error was:
Unable to allocate memory for SSL structures and buffers.
ERRCODE: -1000

And here is my code:

#include <ESP8266WiFi.h>
#include <WiFiClientSecure.h>
#include <base64.h>
#include "OneWire.h"
#include "DallasTemperature.h"
#include <ArduinoJson.h>
#include <string>
using namespace std;
#include <sstream>
#include <iostream>
#include "FirebaseArduino.h"

// Your network SSID and password
const char* ssid = "*****";
const char* password = "*****";

const char* account_sid = "*****";
const char* auth_token = "*****";
String to_number    = "+*****";
String from_number = "+*****";
String message_body    = "Hello from Twilio and the ESP8266!";

// Find the api.twilio.com SHA1 fingerprint using,
//  echo | openssl s_client -connect api.twilio.com:443 | openssl x509 -fingerprint
const char fingerprint[] = "BC B0 1A 32 80 5D E6 E4 A2 29 66 2B 08 C8 E0 4C 45 29 3F D0";

#define ONE_WIRE_BUS 4
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);

#define FIREBASE_HOST "***.firebaseio.com"
#define FIREBASE_AUTH "*****"

float temp1 = 0;
//float temp2 = 0;
String b;
int c;

String urlencode(String str) {
  String encodedString = "";
  char c;
  char code0;
  char code1;
  char code2;
  for (int i = 0; i < str.length(); i++) {
    c = str.charAt(i);
    if (c == ' ') {
      encodedString += '+';
    } else if (isalnum(c)) {
      encodedString += c;
    } else {
      code1 = (c & 0xf) + '0';
      if ((c & 0xf) > 9) {
        code1 = (c & 0xf) - 10 + 'A';
      }
      c = (c >> 4) & 0xf;
      code0 = c + '0';
      if (c > 9) {
        code0 = c - 10 + 'A';
      }
      code2 = '\0';
      encodedString += '%';
      encodedString += code0;
      encodedString += code1;
    }
    yield();
  }
  return encodedString;
}

String get_auth_header(const String& user, const String& password) {
  size_t toencodeLen = user.length() + password.length() + 2;
  char toencode[toencodeLen];
  memset(toencode, 0, toencodeLen);
  snprintf(toencode, toencodeLen, "%s:%s", user.c_str(), password.c_str());
  String encoded = base64::encode((uint8_t*)toencode, toencodeLen - 1);
  String encoded_string = String(encoded);
  std::string::size_type i = 0;
  // Strip newlines (after every 72 characters in spec)
  while (i < encoded_string.length()) {
    i = encoded_string.indexOf('\n', i);
    if (i == -1) {
      break;
    }
    encoded_string.remove(i, 1);
  }
  return "Authorization: Basic " + encoded_string;
}

void setup() {
  Serial.begin(115200); // 115200 or 9600
  delay(1000);        // Give the serial connection time to start before the first print.
  Serial.println(""); // Newline after garbage characters.
  Serial.println(F("+++ Setup."));

  // ----------------------------------------------------
  Serial.println("+ Connect to WiFi. ");
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.print(".");
  }
  Serial.println("");
  Serial.print("+ Connected to WiFi, IP address: ");
  Serial.println(WiFi.localIP());

// ----------------------------------------------------
sensors.begin();
Firebase.begin(FIREBASE_HOST, FIREBASE_AUTH);
}

void loop() {
      sensors.requestTemperatures();
  temp1 = sensors.getTempCByIndex(0);
  Serial.print(temp1);
  b = Firebase.getString("002/alarm");
    c = b.toInt();
    Serial.print(c);
      if (temp1 > c) {
      // Use WiFiClientSecure to create a TLS 1.2 connection.
  //  Note, using a cert fingerprint is required.
  WiFiClientSecure client;
  client.setFingerprint(fingerprint);
  Serial.printf("+ Using fingerprint '%s'\n", fingerprint);
  const char* host = "api.twilio.com";
  const int   httpsPort = 443;
  Serial.print("+ Connecting to ");
  Serial.println(host);
  if (!client.connect(host, httpsPort)) {
    Serial.println("- Connection failed.");
    char buf[200];
                int err = client.getLastSSLError(buf, 199);

                buf[199] = '\0';

                Serial.println("Last SSL error was:");

                Serial.println(buf);

                Serial.print("ERRCODE: "); 
                Serial.println(err);
///* END snippet from pushdata-io project */            
//              return false;
  }
  Serial.println("+ Connected.");
    Serial.println("+ Post an HTTP send SMS request.");
  String post_data = "To=" + urlencode(to_number)
                     + "&From=" + urlencode(from_number)
                     + "&Body=" + urlencode(message_body);
  String auth_header = get_auth_header(account_sid, auth_token);
  String http_request = "POST /2010-04-01/Accounts/" + String(account_sid) + "/Messages HTTP/1.1\r\n"
                        + auth_header + "\r\n" 
                        + "Host: " + host + "\r\n"
                        + "Cache-control: no-cache\r\n"
                        + "User-Agent: ESP8266 Twilio Example\r\n"
                        + "Content-Type: application/x-www-form-urlencoded\r\n"
                        + "Content-Length: " + post_data.length() + "\r\n"
                        + "Connection: close\r\n"
                        + "\r\n"
                        + post_data
                        + "\r\n";
  client.println(http_request);
  // Read the response.
  String response = "";
  while (client.connected()) {
    String line = client.readStringUntil('\n');
    response += (line);
    response += ("\r\n");
  }
  Serial.println("+ Connection is closed.");
  Serial.println("+ Response:");
  Serial.println(response);
      }
  delay(5000);
}

Does that mean that the NodeMCU doesn't have enough memory? I also tried changing delay() to milis(), but that didn't solve the problem.

Any help would be appreciated!

4
  • There should be enough memory, but all that String concatenation you're doing isn't going to help matters. – Majenko Sep 3 '20 at 18:55
  • Thanks for your reply. Do you have any suggestions on how to modify the code? Sorry, I'm new to Arduino. – Nina Sep 3 '20 at 19:17
  • Just print each line or part of line separately. You don't need to have it all in one string. – Majenko Sep 3 '20 at 19:47
  • So if I understand you correcly, I should use empty println(" ") between each println() that has a value. – Nina Sep 7 '20 at 5:04

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