Always get -1 connection refused response from server - iot

I am making a alert device on my node mcu board to report any orders made by customers on my application. The nodemcu should access the network using wifi and call the rest api. I tried researching many sites and modified the code several times, but the response is always -1, connection refused.
tried doing
#include <Arduino.h>
#include <ESP8266WiFi.h>
#include <ESP8266WiFiMulti.h>
#include <ESP8266HTTPClient.h>
#include <WiFiClient.h>
ESP8266WiFiMulti WiFiMulti;
void setup() {
Serial.begin(9600);
// Serial.setDebugOutput(true);
Serial.println();
Serial.println();
Serial.println();
for (uint8_t t = 4; t > 0; t--) {
Serial.printf("[SETUP] WAIT %d...\n", t);
Serial.flush();
delay(1000);
}
WiFi.mode(WIFI_STA);
WiFiMulti.addAP("----", "----");
}
void loop() {
// wait for WiFi connection
if ((WiFiMulti.run() == WL_CONNECTED)) {
WiFiClient client;
HTTPClient http;
Serial.print("[HTTP] begin...\n");
if (http.begin(client, "http://34.87.116.113:80/api/v1/iot/Notify/poll")) { // HTTP
http.setAuthorization("admin", "admin123!");
Serial.print("[HTTP] GET...\n");
// start connection and send HTTP header
int httpCode = http.GET();
// httpCode will be negative on error
if (httpCode > 0) {
// HTTP header has been send and Server response header has been handled
Serial.printf("[HTTP] GET... code: %d\n", httpCode);
// file found at server
if (httpCode == HTTP_CODE_OK || httpCode == HTTP_CODE_MOVED_PERMANENTLY) {
String payload = http.getString();
Serial.println(payload);
}
} else {
Serial.printf("[HTTP] GET... failed, error: %s\n", http.errorToString(httpCode).c_str());
}
http.end();
} else {
Serial.printf("[HTTP} Unable to connect\n");
}
}
delay(5000);
}

Related

Esp8266 Post Request returns error code 415

I am currently developing a project where I want esp8266 to send data to Blazor Server App which is hosted on server, but the problem is the Post request to Blazor's server app api keeps returning error code 415.
#include <ESP8266WiFi.h>
#include <ESP8266WiFiMulti.h>
#include <ESP8266HTTPClient.h>
#include <WiFiClient.h>
const String ssid="";
const String password="";
const String url="http://raspberrypiproject.com/api/values/1";
void setup()
{
Serial.begin(115200);
WiFi.mode(WIFI_STA);
WiFi.begin(ssid,password);
Serial.println();
Serial.print("Connecting");
while(WiFi.status()!=WL_CONNECTED)
{
Serial.print(".");
delay(500);
}
Serial.println();
Serial.print("Connected to ");
Serial.print(WiFi.SSID());
}
void loop() {
if(WiFi.status()==WL_CONNECTED)
{
WiFiClient client;
HTTPClient http;
if(http.begin(client,url))
{
int code=http.GET();
if(code>0)
{
Serial.println(http.getString());
http.addHeader("Content-Type", "application/x-www-form-urlencoded");
Serial.println(http.POST("hellofromEsp8266"));
}
}
}
}
This is my esp8266 code. In the net I found that the cause of the problem is the Content-Type of "http.addHeader("Content-Type", "application/x-www-form-urlencoded")" and the only change in the response code is when I change it to "multipart/form-data" and it returns error code 400. Is my problem in the client or in Blazor Server.

sim808 POST request not sending data

I am trying to send data to a web app using the TCP connection of a SIM808 that is connected to my NodeMcu. Everything appears to work fine, connection is perfect but at the send part, the post request does not execute fully.
below is my code and output
please help check the http_cmd line. In my output, after the content is shown in the output I am suppose to see something like Recv: ### bytes but instead I get ☐fetch over
#include <ESP8266WiFi.h>
#include <DFRobot_sim808.h>
#include <sim808.h>
#include <SoftwareSerial.h>
DFRobot_SIM808 sim808(&Serial);
char http_cmd[] = "POST /tracker/ HTTP/1.1\r\nContent-Type: application/json\r\nContent-Length: 34\r\nHost: haul1.herokuapp.com\r\n\r\n{ \"trackerId\": \"2222\",\"height\": \"42\" }";
char buffer[512];
void setup(){
//mySerial.begin(9600);
Serial.begin(9600);
//******** Initialize sim808 module *************
while(!sim808.init()) {
delay(1000);
Serial.print("Sim808 init error\r\n");
}
delay(3000);
//*********** Attempt DHCP *******************
while(!sim808.join()) {
Serial.println("Sim808 join network error");
delay(2000);
}
//************ Successful DHCP ****************
Serial.print("IP Address is ");
Serial.println(sim808.getIPAddress());
//*********** Establish a TCP connection ************
if(!sim808.connect(TCP,"haul.herokuapp.com", 80)) {
Serial.println("Connect error");
}else{
Serial.println("Connect haul.herokuapp.com success");
}
//*********** Send a GET request *****************
Serial.println("waiting to fetch...");
sim808.send(http_cmd, sizeof(http_cmd)-1);
while (true) {
int ret = sim808.recv(buffer, sizeof(buffer)-1);
if (ret <= 0){
Serial.println("fetch over...");
break;
}
buffer[ret] = '\0';
Serial.print("Recv: ");
Serial.print(ret);
Serial.print(" bytes: ");
Serial.println(buffer);
break;
}
//************* Close TCP or UDP connections **********
sim808.close();
//*** Disconnect wireless connection, Close Moving Scene *******
sim808.disconnect();
}
void loop(){
}
OUTPUT:
OUTPUT from Serial Monitor
Sim808 init error
AT
Sim808 init error
AT
AT+CFUN=1
AT+CPIN?
AT+CSTT="","",""
AT+CIICR
AT+CIFSR
IP Address is 10.10.124.205
AT+CIPSTART="TCP", “haul.herokuapp.com”, 80
Connect haul.herokuapp.com success
waiting to fetch...
AT+CIPSEND=145
POST /tracker/ HTTP/1.1
Content—Type: application/json
Content—Length: 34
Host: haul.herokuapp.com
{"trackerId": "2222","height": "42"}☐fetch over...
AT+CIPSTATUS
AT+CIPSHUT

ESP8266 - Setting Wifi Credentials programmatically and then checking they are valid, and then change them if they are not (without reset)

I have an NodeMCU chip that needs to connect to my home wifi and post an http request. I use the chip in WIFI_STA_AP mode as I need the chip to both accept requests via http and issue requests by http.
I do not want to hard-code my home's SSID/Password into the chip, so I have written some code that places the ESP (NodeMCU) into AP mode, receives the SSID/Pass via an http request and saves it on EEPROM.
This works great.
In the code below, onTestWifi() is called when I call http://192.168.4.1/test_wifi?wifi_ssid=mySsid&wifi_password=myPassword. The ssid and password are provided to the WiFi.begin() function. However, if I accidentally type in the wrong password and use it in WiFi.begin(), the connection will always fail until reset the chip and then insert the correct password.
What am I missing? Is it possible to change the ESP's wifi credentials programmatically, without having to reset the chip? Resetting the chip causes the client (in the case, an iPhone app) to disconnect from the chip and this breaks the entire program flow.
Here's the experimentation code I am using:
#include <ESP8266WiFiMulti.h>
#include <WiFiClient.h>
#include <ESP8266HTTPClient.h>
#include <ESP8266WebServer.h>
#include <ESP8266mDNS.h>
ESP8266WebServer server(80);
ESP8266WiFiMulti WiFiMulti;
void setup() {
Serial.begin(115200);
Serial.println("");
delay(100);
Serial.println("Starting...");
WiFi.persistent(false);
WiFi.mode(WIFI_AP_STA);
WiFi.softAP("APSSID");
IPAddress ip = WiFi.softAPIP();
server.on("/test_wifi", onTestWifi);
server.begin();
yield();
}
void onTestWifi()
{
char ssid[30] = "";
char password[30] = "";
for (int i = 0; i < server.args(); i++)
{
String n = server.argName(i);
String v = server.arg(i);
if (n == "wifi_ssid")
v.toCharArray(ssid, 30);
else if (n == "wifi_password")
v.toCharArray(password, 30);
yield();
}
Serial.print("Connecting to: ");
Serial.print(ssid);
Serial.print(" ");
Serial.println(password);
delay(100);
WiFi.begin(ssid, password);
yield();
int counter = 0;
while (WiFi.status() != WL_CONNECTED && counter < 10)
{ // Wait for the Wi-Fi to connect
delay(1000);
Serial.print(++counter);
Serial.print(' ');
}
if (WiFi.status() != WL_CONNECTED)
{ // Failed to connect.
Serial.println("Connection failed!");
}
else {
Serial.println("Connection succeeded!");
}
yield();
}
void loop() {
server.handleClient();
}```
OK, so I figured it out. Had to add the line WiFi.disconnect(true) in the onTestWifi() function. Apparently it disconnects from the network and erases the credentials. This stuff is very poorly documented and I wasted days on it.
I hope someone finds it useful.
#include <WiFiClient.h>
#include <ESP8266HTTPClient.h>
#include <ESP8266WebServer.h>
#include <ESP8266mDNS.h>
ESP8266WebServer server(80);
ESP8266WiFiMulti WiFiMulti;
void setup() {
Serial.begin(115200);
Serial.println("");
delay(100);
Serial.println("Starting...");
WiFi.persistent(false);
WiFi.mode(WIFI_AP_STA);
WiFi.softAP("APSSID");
IPAddress ip = WiFi.softAPIP();
server.on("/test_wifi", onTestWifi);
server.begin();
yield();
}
void onTestWifi()
{
char ssid[30] = "";
char password[30] = "";
for (int i = 0; i < server.args(); i++)
{
String n = server.argName(i);
String v = server.arg(i);
if (n == "wifi_ssid")
v.toCharArray(ssid, 30);
else if (n == "wifi_password")
v.toCharArray(password, 30);
yield();
}
Serial.print("Connecting to: ");
Serial.print(ssid);
Serial.print(" ");
Serial.println(password);
delay(100);
WiFi.begin(ssid, password);
yield();
int counter = 0;
while (WiFi.status() != WL_CONNECTED && counter < 10)
{ // Wait for the Wi-Fi to connect
delay(1000);
Serial.print(++counter);
Serial.print(' ');
}
if (WiFi.status() != WL_CONNECTED)
{ // Failed to connect.
Serial.println("Connection failed!");
}
else {
Serial.println("Connection succeeded!");
}
WiFi.disconnect(true); // <--- Added this line
yield();
}
void loop() {
server.handleClient();
}

Arduino ESP8266 01 MQTT Raspberry pi

I want to use ESP 8266 01 and arduino uno as client in MQTT. The code For ESP8266 01 is successfully compiled and I'M getting errors in Arduino uno
The error is 'messageTemp' was not declared in this scope
Amd also I have a thought of using stm32xx in client.
If I compile for that
exit status 1
ISO C++ forbids comparison between pointer and integer [-fpermissive]
above is the error I'm getting
1)ESP code
// Loading the ESP8266WiFi library and the PubSubClient library
#include <ESP8266WiFi.h>
#include <PubSubClient.h>
// Change the credentials below, so your ESP8266 connects to your router
const char* ssid = "YOUR_SSID";
const char* password = "YOUR_PASSWORD";
const char* mqtt_server = "YOUR_RPi_IP_Address";
// Initializes the espClient
WiFiClient espClient;
PubSubClient client(espClient);
void setup_wifi() {
delay(10);
// We start by connecting to a WiFi network
Serial.println();
Serial.print("Connecting to ");
Serial.println(ssid);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("");
Serial.print("WiFi connected - ESP IP address: ");
Serial.println(WiFi.localIP());
}
if(topic=="home/office/esp1/gpio2"){
Serial.print("Changing GPIO 2 to ");
if(messageTemp == "1"){
// digitalWrite(ledGPIO2, HIGH);
Serial.print("On");
}
else if(messageTemp == "0"){
// digitalWrite(ledGPIO2, LOW);
Serial.print("Off");
}
}
Serial.println();
}
void reconnect() {
// Loop until we're reconnected
while (!client.connected()) {
Serial.print("Attempting MQTT connection...");
// Attempt to connect
if (client.connect("ESP8266Client")) {
Serial.println("connected");
client.subscribe("home/office/esp1/gpio2");
}
else
{
Serial.print("failed, rc=");
Serial.print(client.state());
Serial.println(" try again in 5 seconds");
// Wait 5 seconds before retrying
delay(5000);
}
}
}
void setup() {
Serial.begin(115200);
setup_wifi();
client.setServer(mqtt_server, 1883);
client.setCallback(callback);
}
void loop() {
if (!client.connected()) {
reconnect();
}
client.loop();
}
Code for Arduino UNO
void setup(){
Serial.begin(9600);
pinMode(12, OUTPUT);
digitalWrite(12, HIGH);
String messageTemp;
}
void callback(String topic, byte* message, unsigned int length) {
Serial.print("Message arrived on topic: ");
Serial.print(topic);
Serial.print(". Message: ");
String messageTemp;
for (int i = 0; i < length; i++) {
Serial.print((char)message[i]);
messageTemp += (char)message[i];
}
Serial.println();
}
void loop ()
{
if (Serial.available()){
char topic = Serial.read();
{
if (topic=="home/office/esp1/gpio2")
{
Serial.print("Changing GPIO 2 to ");
if(messageTemp == "1"){
digitalWrite(12, HIGH);
Serial.print("On");
}
else if(messageTemp == "0")
{
digitalWrite(12, LOW);
Serial.print("Off");
}
}}}}
ESP code doesn't look the whole source code you provided. In case of Arduino UNO, if you're intending to use messageTemp as a global variable, then you need to declare it only one time outside of functions. In the above code, you declared it twice in setup() and callback(), then those are considered as local variables. Even in loop(), there's no declaration, this should create the compile error.

The ESP8266 is not connecting to MQTT broker hivemq

I have a simple code in which I am trying to connect to HiveMQ open broker and subscribe to a topic to listen to incoming messages.
here is the code
#include <ESP8266WiFi.h>
#include <PubSubClient.h>
const char *ssid = "P9Inct"; // cannot be longer than 32 characters!
const char *pass = "P9inct123*"; //
const char *mqtt_server = "broker.hivemq.com";
const int mqtt_port = 1883;
const char *mqtt_user = "testUser";
const char *mqtt_pass = "abc123";
const char *mqtt_client_name = "12312312332212";
#define BUFFER_SIZE 100
String incoming="";
String did="";
String state="";
// Update these with values suitable for your network.
//IPAddress server(172, 16, 0, 2);
String DEVID="8581870006";//"6931108641";//old
WiFiClient wclient;
PubSubClient client(wclient, mqtt_server,mqtt_port);
void callback(const MQTT::Publish& pub) {
// handle message arrived
Serial.print(pub.topic());
Serial.print(" => ");
if (pub.has_stream()) {
uint8_t buf[BUFFER_SIZE];
int read;
while (read = pub.payload_stream()->read(buf, BUFFER_SIZE)) {
Serial.write(buf, read);
}
pub.payload_stream()->stop();
Serial.println("");
} else
Serial.println(pub.payload_string());
////////////////////////////////////////////
incoming=String(pub.payload_string());
Serial.println(pub.payload_string());
Serial.println(incoming);
}
void setup() {
// Setup console
Serial.begin(115200);
delay(10);
Serial.println();
Serial.println();
}
void loop() {
if (WiFi.status() != WL_CONNECTED) {
Serial.print("Connecting to ");
Serial.print(ssid);
Serial.println("...");
WiFi.begin(ssid, pass);
if (WiFi.waitForConnectResult() != WL_CONNECTED)
return;
Serial.println("WiFi connected");
}
if (WiFi.status() == WL_CONNECTED) {
if (!client.connected()) {
Serial.println("Connecting to MQTT server");
if (client.connect(MQTT::Connect(mqtt_client_name)
.set_auth(mqtt_user, mqtt_pass))) {
Serial.println("Connected to MQTT server");
client.set_callback(callback);
client.subscribe("diy/1"+DEVID);
} else {
Serial.println("Could not connect to MQTT server");
}
}
if (client.connected())
client.loop();
}
}
WiFi connection is working fine but, communication via broker is not working and it always gives the message "Could not connect to MQTT server". How to make esp8266 work with HiveMQ broker. The dashboard of borker is
http://www.mqtt-dashboard.com/
So, you are connected. You have unnecessary print line in your loop. Try to adapt on this :
/* Incoming data callback. */
void callback(char* topic, byte* payload, unsigned int length)
{
char payloadStr[length + 1];
memset(payloadStr, 0, length + 1);
strncpy(payloadStr, (char*)payload, length);
Serial.printf("Topic : [%s]\n", topic);
Serial.printf("Payload : %s\n", payloadStr);
}
void performConnect()
{
uint16_t connectionDelay = 5000;
while (!client.connected())
{
if (client.connect(MQTT_CLIENT_ID, MQTT_USERNAME, MQTT_KEY))
{
Serial.printf("Connected to Broker.\n");
client.subscribe("diy/1"+DEVID);
}
else
{
Serial.printf("MQTT Connect failed, rc = %d\n", client.state());
Serial.printf("Trying again in %d msec.\n", connectionDelay);
delay(connectionDelay);
}
}
}
void loop()
{
if (!client.connected())
{
performConnect();
}
client.loop();
}

Resources