WiFiManager is a ESP8266 connection manager that connects the ESP to an access point, or if that fails, turns the ESP into an access point with a web configuration portal to allow changes to the WiFi configuration.

Usage[edit | edit source]

Refer to the example code available at https://github.com/tzapu/WiFiManager/blob/master/examples/

WiFi Manager is capable of handling custom parameters in addition to the WiFi SSID and password. The example code below includes custom parameters that are handled by WiFi Manager and are saved as a JSON file on SPIFFS.

#define LED_BUILTIN 2

#include <FS.h>
#include <ArduinoJson.h>
#include <ESP8266WiFi.h>
#include <DNSServer.h>
#include <ESP8266WebServer.h>
#include <WiFiManager.h>
WiFiClient espClient;

#include <Ticker.h>
Ticker ticker;

bool shouldSaveConfig = false;
char mqtt_server[40] = "mqtt";
char mqtt_port[6] = "1883";
char mqtt_topic[40] = "sensors/esp-sensor";
char poll_interval[6] = "5";
char sensor_name[40] = "sensorA";

void setup() {
	// Setup serial as 8E1 to communicate with sound meter

	// set led pin as output and blink 0.5s interval until connected
	ticker.attach(0.5, led_tick);
	// WiFiManager
	// Local intialization. Once its business is done, there is no need to keep it around
	WiFiManager wifiManager;
	// custom parameters
	WiFiManagerParameter custom_mqtt_server("server", "mqtt server", mqtt_server, 40);
	WiFiManagerParameter custom_mqtt_port("port", "mqtt port", mqtt_port, 6);
	WiFiManagerParameter custom_mqtt_topic("topic", "mqtt topic", mqtt_topic, 40);
	WiFiManagerParameter custom_poll_interval("interval", "poll interval", poll_interval, 6);
	WiFiManagerParameter custom_sensor_name("sensor name", "sensor name", sensor_name, 40);
	// try to connect or fallback to ESP+ChipID AP config mode.
	if ( ! wifiManager.autoConnect()) {
		// reset and try again, or maybe put it to deep sleep
	// read paramters
	strcpy(mqtt_server, custom_mqtt_server.getValue());
	strcpy(mqtt_port, custom_mqtt_port.getValue());
	strcpy(mqtt_topic, custom_mqtt_topic.getValue());
	strcpy(poll_interval, custom_poll_interval.getValue());
	strcpy(sensor_name, custom_sensor_name.getValue());
	// if we went through config, we should save our changes.
	if (shouldSaveConfig) save_settings();
	// no more blinking

void loop() {

// WiFiManager requiring config save callback
void saveConfigCallback () {
	shouldSaveConfig = true;

// WiFiManager entering configuration mode callback
void configModeCallback(WiFiManager *myWiFiManager) {
	// entered config mode, make led toggle faster
	ticker.attach(0.2, led_tick);

// Saves custom parameters to /config.json on SPIFFS
void save_settings() {
	DynamicJsonBuffer jsonBuffer;
	JsonObject& json = jsonBuffer.createObject();
	json["mqtt_server"] = mqtt_server;
	json["mqtt_port"] = mqtt_port;
	json["mqtt_topic"] = mqtt_topic;
	json["poll_interval"] = poll_interval;
	json["sensor_name"] = sensor_name;

	File configFile = SPIFFS.open("/config.json", "w");

// Loads custom parameters from /config.json on SPIFFS
void load_settings() {
	if (SPIFFS.begin() && SPIFFS.exists("/config.json")) {
		File configFile = SPIFFS.open("/config.json", "r");
		if (configFile) {
			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()) {
				strcpy(mqtt_server, json["mqtt_server"]);
				strcpy(mqtt_port, json["mqtt_port"]);
				strcpy(mqtt_topic, json["mqtt_topic"]);
				strcpy(poll_interval, json["poll_interval"]);
				strcpy(sensor_name, json["sensor_name"]);

// Called by ticker for LED toggle
void led_tick() {
	// toggle LEF state
	int state = digitalRead(LED_BUILTIN);
	digitalWrite(LED_BUILTIN, !state);

See Also[edit | edit source]