[GH-ISSUE #1061] Example ArduinoJson migration from version 5 to 6 #906

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opened 2026-02-28 01:27:36 +03:00 by kerem · 1 comment

kerem commented

2026-02-28 01:27:36 +03:00

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Originally created by @rubengr on GitHub (May 22, 2020).
Original GitHub issue: https://github.com/tzapu/WiFiManager/issues/1061

ArduinoJson have a new version that doesn't work with actual code in examples. So i tested the example AutoConnectWithFSParametersAndCustomIP with some modifications to work with new version that i share with people that wants too.

#include <FS.h>          // this needs to be first, or it all crashes and burns...
#include <WiFiManager.h> // https://github.com/tzapu/WiFiManager
#include <ArduinoJson.h> // https://github.com/bblanchon/ArduinoJson

#ifdef ESP32
  #include <SPIFFS.h>
#endif

//define your default values here, if there are different values in config.json, they are overwritten.
char mqtt_server[40];
char mqtt_port[6]  = "8080";
char api_token[32] = "YOUR_API_TOKEN";

//default custom static IP
char static_ip[16] = "10.0.1.56";
char static_gw[16] = "10.0.1.1";
char static_sn[16] = "255.255.255.0";

//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 setupSpiffs(){
  //clean FS, for testing
  // SPIFFS.format();

  //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 = SPIFFS.open("/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);
        DynamicJsonDocument json(ESP.getMaxFreeBlockSize());
        DeserializationError error = deserializeJson(json,buf.get()); 
        //JsonObject& json = jsonBuffer.parseObject();
        //json.printTo(Serial);
        serializeJson(json,Serial);
        if (!error) {
          Serial.println("\nparsed json");

          strcpy(mqtt_server, json["mqtt_server"]);
          strcpy(mqtt_port, json["mqtt_port"]);
          strcpy(api_token, json["api_token"]);

          if(json["ip"]) {
            Serial.println("setting custom ip from config");
            strcpy(static_ip, json["ip"]);
            strcpy(static_gw, json["gateway"]);
            strcpy(static_sn, json["subnet"]);
            Serial.println(static_ip);
          } else {
            Serial.println("no custom ip in config");
          }

        } else {
          Serial.println("failed to load json config");
        }
      }
    }
  } else {
    Serial.println("failed to mount FS");
  }
  //end read
}

void setup() {
  WiFi.mode(WIFI_STA); // explicitly set mode, esp defaults to STA+AP  
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println();

  setupSpiffs();

  // WiFiManager, Local intialization. Once its business is done, there is no need to keep it around
  WiFiManager wm;

  //set config save notify callback
  wm.setSaveConfigCallback(saveConfigCallback);

  // setup custom parameters
  // 
  // 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_mqtt_server("server", "mqtt server", mqtt_server, 40);
  WiFiManagerParameter custom_mqtt_port("port", "mqtt port", mqtt_port, 6);
  WiFiManagerParameter custom_api_token("api", "api token", "", 32);

  //add all your parameters here
  wm.addParameter(&custom_mqtt_server);
  wm.addParameter(&custom_mqtt_port);
  wm.addParameter(&custom_api_token);

  // set static ip
  IPAddress _ip,_gw,_sn;
  _ip.fromString(static_ip);
  _gw.fromString(static_gw);
  _sn.fromString(static_sn);
  wm.setSTAStaticIPConfig(_ip, _gw, _sn);

  //reset settings - wipe credentials for testing
  //wm.resetSettings();

  //automatically connect using saved credentials if they exist
  //If connection fails it starts an access point with the specified name
  //here  "AutoConnectAP" if empty will auto generate basedcon chipid, if password is blank it will be anonymous
  //and goes into a blocking loop awaiting configuration
  if (!wm.autoConnect("AutoConnectAP", "password")) {
    Serial.println("failed to connect and hit timeout");
    delay(3000);
    // if we still have not connected restart and try all over again
    ESP.restart();
    delay(5000);
  }

  //if you get here you have connected to the WiFi
  Serial.println("connected...yeey :)");

  //read updated parameters
  strcpy(mqtt_server, custom_mqtt_server.getValue());
  strcpy(mqtt_port, custom_mqtt_port.getValue());
  strcpy(api_token, custom_api_token.getValue());

  //save the custom parameters to FS
  if (shouldSaveConfig) {
    Serial.println("saving config");
    DynamicJsonDocument json(ESP.getMaxFreeBlockSize());
    //JsonObject& json = jsonBuffer.createObject();
    json["mqtt_server"] = mqtt_server;
    json["mqtt_port"]   = mqtt_port;
    json["api_token"]   = api_token;

    json["ip"]          = WiFi.localIP().toString();
    json["gateway"]     = WiFi.gatewayIP().toString();
    json["subnet"]      = WiFi.subnetMask().toString();

    File configFile = SPIFFS.open("/config.json", "w");
    if (!configFile) {
      Serial.println("failed to open config file for writing");
    }
    serializeJsonPretty(json,Serial);
    //json.prettyPrintTo(Serial);
    serializeJson(json,configFile);
    //json.printTo(configFile);
    configFile.close();
    //end save
    shouldSaveConfig = false;
  }

  Serial.println("local ip");
  Serial.println(WiFi.localIP());
  Serial.println(WiFi.gatewayIP());
  Serial.println(WiFi.subnetMask());
}

void loop() {
  // put your main code here, to run repeatedly:


}

Originally created by @rubengr on GitHub (May 22, 2020). Original GitHub issue: https://github.com/tzapu/WiFiManager/issues/1061 ArduinoJson have a new version that doesn't work with actual code in examples. So i tested the example AutoConnectWithFSParametersAndCustomIP with some modifications to work with new version that i share with people that wants too. ``` #include <FS.h> // this needs to be first, or it all crashes and burns... #include <WiFiManager.h> // https://github.com/tzapu/WiFiManager #include <ArduinoJson.h> // https://github.com/bblanchon/ArduinoJson #ifdef ESP32 #include <SPIFFS.h> #endif //define your default values here, if there are different values in config.json, they are overwritten. char mqtt_server[40]; char mqtt_port[6] = "8080"; char api_token[32] = "YOUR_API_TOKEN"; //default custom static IP char static_ip[16] = "10.0.1.56"; char static_gw[16] = "10.0.1.1"; char static_sn[16] = "255.255.255.0"; //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 setupSpiffs(){ //clean FS, for testing // SPIFFS.format(); //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 = SPIFFS.open("/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); DynamicJsonDocument json(ESP.getMaxFreeBlockSize()); DeserializationError error = deserializeJson(json,buf.get()); //JsonObject& json = jsonBuffer.parseObject(); //json.printTo(Serial); serializeJson(json,Serial); if (!error) { Serial.println("\nparsed json"); strcpy(mqtt_server, json["mqtt_server"]); strcpy(mqtt_port, json["mqtt_port"]); strcpy(api_token, json["api_token"]); if(json["ip"]) { Serial.println("setting custom ip from config"); strcpy(static_ip, json["ip"]); strcpy(static_gw, json["gateway"]); strcpy(static_sn, json["subnet"]); Serial.println(static_ip); } else { Serial.println("no custom ip in config"); } } else { Serial.println("failed to load json config"); } } } } else { Serial.println("failed to mount FS"); } //end read } void setup() { WiFi.mode(WIFI_STA); // explicitly set mode, esp defaults to STA+AP // put your setup code here, to run once: Serial.begin(115200); Serial.println(); setupSpiffs(); // WiFiManager, Local intialization. Once its business is done, there is no need to keep it around WiFiManager wm; //set config save notify callback wm.setSaveConfigCallback(saveConfigCallback); // setup custom parameters // // 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_mqtt_server("server", "mqtt server", mqtt_server, 40); WiFiManagerParameter custom_mqtt_port("port", "mqtt port", mqtt_port, 6); WiFiManagerParameter custom_api_token("api", "api token", "", 32); //add all your parameters here wm.addParameter(&custom_mqtt_server); wm.addParameter(&custom_mqtt_port); wm.addParameter(&custom_api_token); // set static ip IPAddress _ip,_gw,_sn; _ip.fromString(static_ip); _gw.fromString(static_gw); _sn.fromString(static_sn); wm.setSTAStaticIPConfig(_ip, _gw, _sn); //reset settings - wipe credentials for testing //wm.resetSettings(); //automatically connect using saved credentials if they exist //If connection fails it starts an access point with the specified name //here "AutoConnectAP" if empty will auto generate basedcon chipid, if password is blank it will be anonymous //and goes into a blocking loop awaiting configuration if (!wm.autoConnect("AutoConnectAP", "password")) { Serial.println("failed to connect and hit timeout"); delay(3000); // if we still have not connected restart and try all over again ESP.restart(); delay(5000); } //if you get here you have connected to the WiFi Serial.println("connected...yeey :)"); //read updated parameters strcpy(mqtt_server, custom_mqtt_server.getValue()); strcpy(mqtt_port, custom_mqtt_port.getValue()); strcpy(api_token, custom_api_token.getValue()); //save the custom parameters to FS if (shouldSaveConfig) { Serial.println("saving config"); DynamicJsonDocument json(ESP.getMaxFreeBlockSize()); //JsonObject& json = jsonBuffer.createObject(); json["mqtt_server"] = mqtt_server; json["mqtt_port"] = mqtt_port; json["api_token"] = api_token; json["ip"] = WiFi.localIP().toString(); json["gateway"] = WiFi.gatewayIP().toString(); json["subnet"] = WiFi.subnetMask().toString(); File configFile = SPIFFS.open("/config.json", "w"); if (!configFile) { Serial.println("failed to open config file for writing"); } serializeJsonPretty(json,Serial); //json.prettyPrintTo(Serial); serializeJson(json,configFile); //json.printTo(configFile); configFile.close(); //end save shouldSaveConfig = false; } Serial.println("local ip"); Serial.println(WiFi.localIP()); Serial.println(WiFi.gatewayIP()); Serial.println(WiFi.subnetMask()); } void loop() { // put your main code here, to run repeatedly: } ```