Problem with code Code used to demonstrate the MQTT connection to Adafruit.io broker using SIM900 / SIM800 GSM module: ('amp' não foi declarado neste escopo.)

int led = 13;
unsigned int Counter = 0;
unsigned long datalength, CheckSum, RLength;
unsigned short topiclength;
unsigned char topic[30];
char str[250];
unsigned char encodedByte;
int X;
unsigned short MQTTProtocolNameLength;
unsigned short MQTTClientIDLength;
unsigned short MQTTUsernameLength;
unsigned short MQTTPasswordLength;
const char MQTTHost[30] = " “;
const char MQTTPort[10] = “1883”;
const char MQTTClientID[20] = “ABCDEF”;
const char MQTTTopic[30] = “jonatasnunes/feeds/vazao-de-saudade”;
const char MQTTProtocolName[10] = “MQTT”;
const char MQTTLVL = 0x03;
const char MQTTFlags = 0xC2;
const unsigned int MQTTKeepAlive = 60;
const char MQTTUsername[30] = “jonatasnunes”;
const char MQTTPassword[35] = “993df7b916494d19b430d53cfcbe677d”;
const char MQTTQOS = 0x00;
const char MQTTPacketID = 0x0001;
void setup() {
pinMode(led, OUTPUT);
Serial.begin(9600);
Serial.println(“Arduino MQTT Tutorial, Valetron Systems @www.raviyp.com “);
delay(3000);
}
void SendConnectPacket(void) {
Serial.print(”\r\nAT+CIPSEND\r\n”);
delay(3000);
Serial.write(0x10);
MQTTProtocolNameLength = strlen(MQTTProtocolName);
MQTTClientIDLength = strlen(MQTTClientID);
MQTTUsernameLength = strlen(MQTTUsername);
MQTTPasswordLength = strlen(MQTTPassword);
datalength = MQTTProtocolNameLength + 2 + 4 + MQTTClientIDLength + 2 + MQTTUsernameLength + 2 + MQTTPasswordLength + 2;
X = datalength;
do {
encodedByte = X % 128;
X = X / 128;
if (X > 0) {
encodedByte |= 128;
}
Serial.write(encodedByte);
}
while (X > 0);
Serial.write(MQTTProtocolNameLength >> 8);
Serial.write(MQTTProtocolNameLength & 0xFF);
Serial.print(MQTTProtocolName);
Serial.write(MQTTLVL); // LVL
Serial.write(MQTTFlags); // Flags
Serial.write(MQTTKeepAlive >> 8);
Serial.write(MQTTKeepAlive & 0xFF);
Serial.write(MQTTClientIDLength >> 8);
Serial.write(MQTTClientIDLength & 0xFF);
Serial.print(MQTTClientID);
Serial.write(MQTTUsernameLength >> 8);
Serial.write(MQTTUsernameLength & 0xFF);
Serial.print(MQTTUsername);
Serial.write(MQTTPasswordLength >> 8);
Serial.write(MQTTPasswordLength & 0xFF);
Serial.print(MQTTPassword);
Serial.write(0x1A);
}
void SendPublishPacket(void) {
Serial.print(”\r\nAT+CIPSEND\r\n");
delay(3000);
memset(str, 0, 250);
topiclength = sprintf((char * ) topic, MQTTTopic);
datalength = sprintf((char * ) str, “%s%u”, topic, Counter);
delay(1000);
Serial.write(0x30);
X = datalength + 2;
do {
encodedByte = X % 128;
X = X / 128;
if (X > 0) {
encodedByte |= 128;
}
Serial.write(encodedByte);
}
while (X > 0);
Serial.write(topiclength >> 8);
Serial.write(topiclength & 0xFF);
Serial.print(str);
Serial.write(0x1A);
}
void SendSubscribePacket(void) {
Serial.print("\r\nAT+CIPSEND\r\n");
delay(3000);
memset(str, 0, 250);
topiclength = strlen(MQTTTopic);
datalength = 2 + 2 + topiclength + 1;
delay(1000);
Serial.write(0x82);
X = datalength;
do {
encodedByte = X % 128;
X = X / 128;
if (X > 0) {
encodedByte |= 128;
}
Serial.write(encodedByte);
}
while (X > 0);
Serial.write(MQTTPacketID >> 8);
Serial.write(MQTTPacketID & 0xFF);
Serial.write(topiclength >> 8);
Serial.write(topiclength & 0xFF);
Serial.print(MQTTTopic);
Serial.write(MQTTQOS);
Serial.write(0x1A);
}
void loop() {
Serial.print(“AT+CIPSHUT\r\n”);
delay(2000);
Serial.print(“AT+CSTT=“www”,”",""\r\n");
delay(1000);
Serial.print(“AT+CIPMODE=0\r\n”);
delay(1000);
Serial.print(“AT+CIICR\r\n”);
delay(9000);
Serial.print(“AT+CIPSTART=“TCP”,”",“1883”\r\n");
delay(6000);
SendConnectPacket();
delay(5000);
SendSubscribePacket();
delay(5000);
while (1) {
if (Serial.available() > 0) {
str[0] = Serial.read();
Serial.write(str[0]);
if (str[0] == ‘N’)
digitalWrite(led, HIGH);
if (str[0] == ‘F’)
digitalWrite(led, LOW);
}
}
}

(‘amp’ was not declared in this scope.)