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#include <FS.h> //this needs to be first, or it all crashes and burns...
#include <ESP8266WiFi.h> //
//needed for library
#include <DNSServer.h>
#include <ESP8266WebServer.h>
#include <WiFiManager.h> //
#include <ArduinoJson.h> //
#include <BlynkSimpleEsp8266.h>
//define your default values here, if there are different values in config.json, they are overwritten.
char blynk_token[33] = "YOUR_BLYNK_TOKEN";
//flag for saving data
bool shouldSaveConfig = false;
//callback notifying us of the need to save config
void saveConfigCallback () {
Serial.println("Should save config");
shouldSaveConfig = true;
void setup() {
// put your setup code here, to run once:
//clean FS, for testing
//read configuration from FS json
Serial.println("mounting FS...");
if (SPIFFS.begin()) {
Serial.println("mounted file system");
if (SPIFFS.exists("/config.json")) {
//file exists, reading and loading
Serial.println("reading config file");
File configFile ="/config.json", "r");
if (configFile) {
Serial.println("opened config file");
size_t size = configFile.size();
// Allocate a buffer to store contents of the file.
std::unique_ptr<char[]> buf(new char[size]);
configFile.readBytes(buf.get(), size);
DynamicJsonBuffer jsonBuffer;
JsonObject& json = jsonBuffer.parseObject(buf.get());
if (json.success()) {
Serial.println("\nparsed json");
strcpy(blynk_token, json["blynk_token"]);
} else {
Serial.println("failed to load json config");
} else {
Serial.println("failed to mount FS");
//end read
// The extra parameters to be configured (can be either global or just in the setup)
// After connecting, parameter.getValue() will get you the configured value
// id/name placeholder/prompt default length
WiFiManagerParameter custom_blynk_token("blynk", "blynk token", blynk_token, 32);
//Local intialization. Once its business is done, there is no need to keep it around
WiFiManager wifiManager;
//set config save notify callback
//add all your parameters here
//reset settings - for testing
//set minimu quality of signal so it ignores AP's under that quality
//defaults to 8%
//sets timeout until configuration portal gets turned off
//useful to make it all retry or go to sleep
//in seconds
//fetches ssid and pass and tries to connect
//if it does not connect it starts an access point with the specified name
//here "AutoConnectAP"
//and goes into a blocking loop awaiting configuration
if (!wifiManager.autoConnect("BlynkNode", "password")) {
Serial.println("failed to connect and hit timeout");
//reset and try again, or maybe put it to deep sleep
//if you get here you have connected to the WiFi
Serial.println("connected...yeey :)");
//read updated parameters
strcpy(blynk_token, custom_blynk_token.getValue());
//save the custom parameters to FS
if (shouldSaveConfig) {
Serial.println("saving config");
DynamicJsonBuffer jsonBuffer;
JsonObject& json = jsonBuffer.createObject();
json["blynk_token"] = blynk_token;
File configFile ="/config.json", "w");
if (!configFile) {
Serial.println("failed to open config file for writing");
//end save
void loop() {
// put your main code here, to run repeatedly:;
boolean lit = false;
lit = !lit;
//LED on V1
Blynk.virtualWrite(1, lit * 255);
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