Hi, all 
I’m having an unusual problem with and Arduino ESP example(CaptivePortalAdvanced).
This example redirect de user to a web page to configure Wifi credentials.
The things is in arduino it works perfect, but in platformIO(VScode and Atom version) it does not work.
It redirect you to the signing page but this page is empty, the same code compiled and uploaded in arduino IDE works good.
Can someone test it to see if this is a particular problem of my computer or is a general thing?
I use an Adafruit Huzzah board, and my OS is Debian
This is the code I’m using
#include <ESP8266WiFi.h>
#include <WiFiClient.h>
#include <ESP8266WebServer.h>
#include <DNSServer.h>
#include <ESP8266mDNS.h>
#include <EEPROM.h>
/* Set these to your desired softAP credentials. They are not configurable at runtime */
const char *softAP_ssid = "ESP_ap";
const char *softAP_password = "12345678";
const char *myHostname = "esp8266";
/* Don't set this wifi credentials. They are configurated at runtime and stored on EEPROM */
char ssid[32] = "";
char password[32] = "";
// DNS server
const byte DNS_PORT = 53;
DNSServer dnsServer;
// Web server
ESP8266WebServer server(80);
/* Soft AP network parameters */
IPAddress apIP(192, 168, 4, 1);
IPAddress netMsk(255, 255, 255, 0);
/** Should I connect to WLAN asap? */
boolean connect;
/** Last time I tried to connect to WLAN */
long lastConnectTry = 0;
/** Current WLAN status */
int status = WL_IDLE_STATUS;
String toStringIp(IPAddress ip);
boolean isIp(String str);
void handleNotFound();
void handleWifiSave();
void handleWifi();
boolean captivePortal();
void handleRoot();
void saveCredentials();
void loadCredentials();
void connectWifi();
void setup() {
delay(1000);
Serial.begin(9600);
Serial.println();
Serial.print("Configuring access point...");
/* You can remove the password parameter if you want the AP to be open. */
WiFi.softAPConfig(apIP, apIP, netMsk);
WiFi.softAP(softAP_ssid, softAP_password);
delay(500); // Without delay I've seen the IP address blank
Serial.print("AP IP address: ");
Serial.println(WiFi.softAPIP());
/* Setup the DNS server redirecting all the domains to the apIP */
dnsServer.setErrorReplyCode(DNSReplyCode::NoError);
dnsServer.start(DNS_PORT, "*", apIP);
/* Setup web pages: root, wifi config pages, SO captive portal detectors and not found. */
server.on("/", handleRoot);
server.on("/wifi", handleWifi);
server.on("/wifisave", handleWifiSave);
server.on("/generate_204", handleRoot); //Android captive portal. Maybe not needed. Might be handled by notFound handler.
server.on("/fwlink", handleRoot); //Microsoft captive portal. Maybe not needed. Might be handled by notFound handler.
server.onNotFound ( handleNotFound );
server.begin(); // Web server start
Serial.println("HTTP server started");
loadCredentials(); // Load WLAN credentials from network
connect = strlen(ssid) > 0; // Request WLAN connect if there is a SSID
}
void connectWifi() {
Serial.println("Connecting as wifi client...");
WiFi.disconnect();
WiFi.begin ( ssid, password );
int connRes = WiFi.waitForConnectResult();
Serial.print ( "connRes: " );
Serial.println ( connRes );
}
void loop() {
if (connect) {
Serial.println ( "Connect requested" );
connect = false;
connectWifi();
lastConnectTry = millis();
}
{
int s = WiFi.status();
if (s == 0 && millis() > (lastConnectTry + 60000) ) {
/* If WLAN disconnected and idle try to connect */
/* Don't set retry time too low as retry interfere the softAP operation */
connect = true;
}
if (status != s) { // WLAN status change
Serial.print ( "Status: " );
Serial.println ( s );
status = s;
if (s == WL_CONNECTED) {
/* Just connected to WLAN */
Serial.println ( "" );
Serial.print ( "Connected to " );
Serial.println ( ssid );
Serial.print ( "IP address: " );
Serial.println ( WiFi.localIP() );
// Setup MDNS responder
if (!MDNS.begin(myHostname)) {
Serial.println("Error setting up MDNS responder!");
} else {
Serial.println("mDNS responder started");
// Add service to MDNS-SD
MDNS.addService("http", "tcp", 80);
}
} else if (s == WL_NO_SSID_AVAIL) {
WiFi.disconnect();
}
}
}
// Do work:
//DNS
dnsServer.processNextRequest();
//HTTP
server.handleClient();
}
/** Load WLAN credentials from EEPROM */
void loadCredentials() {
EEPROM.begin(512);
EEPROM.get(0, ssid);
EEPROM.get(0+sizeof(ssid), password);
char ok[2+1];
EEPROM.get(0+sizeof(ssid)+sizeof(password), ok);
EEPROM.end();
if (String(ok) != String("OK")) {
ssid[0] = 0;
password[0] = 0;
}
Serial.println("Recovered credentials:");
Serial.println(ssid);
Serial.println(strlen(password)>0?"********":"<no password>");
}
/** Store WLAN credentials to EEPROM */
void saveCredentials() {
EEPROM.begin(512);
EEPROM.put(0, ssid);
EEPROM.put(0+sizeof(ssid), password);
char ok[2+1] = "OK";
EEPROM.put(0+sizeof(ssid)+sizeof(password), ok);
EEPROM.commit();
EEPROM.end();
}
/** Handle root or redirect to captive portal */
void handleRoot() {
if (captivePortal()) { // If caprive portal redirect instead of displaying the page.
return;
}
server.sendHeader("Cache-Control", "no-cache, no-store, must-revalidate");
server.sendHeader("Pragma", "no-cache");
server.sendHeader("Expires", "-1");
server.setContentLength(CONTENT_LENGTH_UNKNOWN);
server.send(200, "text/html", ""); // Empty content inhibits Content-length header so we have to close the socket ourselves.
server.sendContent(
"<html><head></head><body>"
"<h1>HELLO WORLD!!</h1>"
);
if (server.client().localIP() == apIP) {
server.sendContent(String("<p>You are connected through the soft AP: ") + softAP_ssid + "</p>");
} else {
server.sendContent(String("<p>You are connected through the wifi network: ") + ssid + "</p>");
}
server.sendContent(
"<p>You may want to <a href='/wifi'>config the wifi connection</a>.</p>"
"</body></html>"
);
server.client().stop(); // Stop is needed because we sent no content length
}
/** Redirect to captive portal if we got a request for another domain. Return true in that case so the page handler do not try to handle the request again. */
boolean captivePortal() {
if (!isIp(server.hostHeader()) && server.hostHeader() != (String(myHostname)+".local")) {
Serial.print("Request redirected to captive portal");
server.sendHeader("Location", String("http://") + toStringIp(server.client().localIP()), true);
server.send ( 302, "text/plain", ""); // Empty content inhibits Content-length header so we have to close the socket ourselves.
server.client().stop(); // Stop is needed because we sent no content length
return true;
}
return false;
}
/** Wifi config page handler */
void handleWifi() {
server.sendHeader("Cache-Control", "no-cache, no-store, must-revalidate");
server.sendHeader("Pragma", "no-cache");
server.sendHeader("Expires", "-1");
server.setContentLength(CONTENT_LENGTH_UNKNOWN);
server.send(200, "text/html", ""); // Empty content inhibits Content-length header so we have to close the socket ourselves.
server.sendContent(
"<html><head></head><body>"
"<h1>Wifi config</h1>"
);
if (server.client().localIP() == apIP) {
server.sendContent(String("<p>You are connected through the soft AP: ") + softAP_ssid + "</p>");
} else {
server.sendContent(String("<p>You are connected through the wifi network: ") + ssid + "</p>");
}
server.sendContent(
"\r\n<br />"
"<table><tr><th align='left'>SoftAP config</th></tr>"
);
server.sendContent(String() + "<tr><td>SSID " + String(softAP_ssid) + "</td></tr>");
server.sendContent(String() + "<tr><td>IP " + toStringIp(WiFi.softAPIP()) + "</td></tr>");
server.sendContent(
"</table>"
"\r\n<br />"
"<table><tr><th align='left'>WLAN config</th></tr>"
);
server.sendContent(String() + "<tr><td>SSID " + String(ssid) + "</td></tr>");
server.sendContent(String() + "<tr><td>IP " + toStringIp(WiFi.localIP()) + "</td></tr>");
server.sendContent(
"</table>"
"\r\n<br />"
"<table><tr><th align='left'>WLAN list (refresh if any missing)</th></tr>"
);
Serial.println("scan start");
int n = WiFi.scanNetworks();
Serial.println("scan done");
if (n > 0) {
for (int i = 0; i < n; i++) {
server.sendContent(String() + "\r\n<tr><td>SSID " + WiFi.SSID(i) + String((WiFi.encryptionType(i) == ENC_TYPE_NONE)?" ":" *") + " (" + WiFi.RSSI(i) + ")</td></tr>");
}
} else {
server.sendContent(String() + "<tr><td>No WLAN found</td></tr>");
}
server.sendContent(
"</table>"
"\r\n<br /><form method='POST' action='wifisave'><h4>Connect to network:</h4>"
"<input type='text' placeholder='network' name='n'/>"
"<br /><input type='password' placeholder='password' name='p'/>"
"<br /><input type='submit' value='Connect/Disconnect'/></form>"
"<p>You may want to <a href='/'>return to the home page</a>.</p>"
"</body></html>"
);
server.client().stop(); // Stop is needed because we sent no content length
}
/** Handle the WLAN save form and redirect to WLAN config page again */
void handleWifiSave() {
Serial.println("wifi save");
server.arg("n").toCharArray(ssid, sizeof(ssid) - 1);
server.arg("p").toCharArray(password, sizeof(password) - 1);
server.sendHeader("Location", "wifi", true);
server.sendHeader("Cache-Control", "no-cache, no-store, must-revalidate");
server.sendHeader("Pragma", "no-cache");
server.sendHeader("Expires", "-1");
server.send ( 302, "text/plain", ""); // Empty content inhibits Content-length header so we have to close the socket ourselves.
server.client().stop(); // Stop is needed because we sent no content length
saveCredentials();
connect = strlen(ssid) > 0; // Request WLAN connect with new credentials if there is a SSID
}
void handleNotFound() {
if (captivePortal()) { // If caprive portal redirect instead of displaying the error page.
return;
}
String message = "File Not Found\n\n";
message += "URI: ";
message += server.uri();
message += "\nMethod: ";
message += ( server.method() == HTTP_GET ) ? "GET" : "POST";
message += "\nArguments: ";
message += server.args();
message += "\n";
for ( uint8_t i = 0; i < server.args(); i++ ) {
message += " " + server.argName ( i ) + ": " + server.arg ( i ) + "\n";
}
server.sendHeader("Cache-Control", "no-cache, no-store, must-revalidate");
server.sendHeader("Pragma", "no-cache");
server.sendHeader("Expires", "-1");
server.send ( 404, "text/plain", message );
}
/** Is this an IP? */
boolean isIp(String str) {
for (int i = 0; i < str.length(); i++) {
int c = str.charAt(i);
if (c != '.' && (c < '0' || c > '9')) {
return false;
}
}
return true;
}
/** IP to String? */
String toStringIp(IPAddress ip) {
String res = "";
for (int i = 0; i < 3; i++) {
res += String((ip >> (8 * i)) & 0xFF) + ".";
}
res += String(((ip >> 8 * 3)) & 0xFF);
return res;
}