ESP32 MQTT Publish and Subscribe RFID ID No, LED on/off/flash
/*********
Rui Santos
Complete project details at https://randomnerdtutorials.com
*********/
#include <WiFi.h>
#include <PubSubClient.h>
#include <SPI.h>
#include "MFRC522.h"
const int RST_PIN = 22; // Reset pin
const int SS_PIN = 21; // Slave select pin
//==========================
//esp32 mfrc522
//21 SDA
//18 SCK
//23 MOSI
//21 MISO
//22 RST
//GND GND
//3.3v 3.3V
//==========================
// Update these with values suitable for your network.
//const char *ssid = "PTS-2F";
//const char *pass = "";
//const char *ssid = "WBR-2200";
//const char *pass = "0226452362";
const char *ssid = "74170287";
const char *pass = "24063173";
//const char *ssid = "yourSSID"; // change according to your Network - cannot be longer than 32 characters!
//const char *pass = "yourPASSWORD"; // change according to your Network
#define MQTTid "" //id of this mqtt client
#define MQTTip "broker.mqtt-dashboard.com" //ip address or hostname of the mqtt broker
#define MQTTport 1883 //port of the mqtt broker
#define MQTTuser "alex9ufo" //username of this mqtt client
#define MQTTpsw "alex1234" //password of this mqtt client
//#define MQTTuser "your_username" //username of this mqtt client
//#define MQTTpsw "your_password" //password of this mqtt client
#define MQTTpubQos 2 //qos of publish (see README)
#define MQTTsubQos 1 //qos of subscribe
MFRC522 mfrc522(SS_PIN, RST_PIN); // Create MFRC522 instance
//Variables
long lastMsg = 0;
char jsonChar[100];
String IDNo_buf="";
const int BUILTIN_LED = 2; //D2
bool Flash = false; //true
//=============================================================================
boolean pendingDisconnect = false;
void mqttConnectedCb(); // on connect callback
void mqttDisconnectedCb(); // on disconnect callback
void mqttDataCb(char* topic, byte* payload, unsigned int length); // on new message callback
WiFiClient wclient;
PubSubClient client(MQTTip, MQTTport, mqttDataCb, wclient);
//=============================================================================
String printHex(byte *buffer, byte bufferSize) {
String id = "";
for (byte i = 0; i < bufferSize; i++) {
id += buffer[i] < 0x10 ? "0" : "";
id += String(buffer[i], HEX);
}
return id;
}
//=============================================================================
void mqttConnectedCb() {
Serial.println("connected");
// Once connected, publish an announcement...
client.publish("alex9ufo/outTopic/RFID/json", jsonChar, MQTTpubQos, true); // true means retain
// ... and resubscribe
client.subscribe("alex9ufo/inTopic", MQTTsubQos);
}
//=============================================================================
void mqttDisconnectedCb() {
Serial.println("disconnected");
}
//=============================================================================
void mqttDataCb(char* topic, byte* payload, unsigned int length) {
/*
you can convert payload to a C string appending a null terminator to it;
this is possible when the message (including protocol overhead) doesn't
exceeds the MQTT_MAX_PACKET_SIZE defined in the library header.
you can consider safe to do so when the length of topic plus the length of
message doesn't exceeds 115 characters
*/
char* message = (char *) payload;
message[length] = 0;
Serial.print("Message arrived [");
Serial.print(topic);
Serial.print("] ");
Serial.println(message);
// Switch on the LED if an 1 was received as first character
if (message[0] == '0') {
digitalWrite(BUILTIN_LED, LOW); // Turn the LED on (Note that LOW is the voltage level
// but actually the LED is on; this is because
Serial.println("Received 0 , Send LOW TO BuildIn_LED");
}
if (message[0] == '1') {
digitalWrite(BUILTIN_LED, HIGH); // Turn the LED off (Note that HIGH is the voltage level
// but actually the LED is on; this is because
Serial.println("Received 1 , Send HIGH TO BuildIn_LED");
}
if (message[0] == '2') {
digitalWrite(BUILTIN_LED, HIGH); // Turn the LED off (Note that HIGH is the voltage level
// but actually the LED is on; this is because
Serial.println("Received 2 , Flashing BuildIn_LED ");
Flash = true;
} //if (message[0] == '2')
}
//======================================================
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, pass);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("");
Serial.println("WiFi connected");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
}
//======================================================
void setup() {
Serial.begin(115200);
setup_wifi();
pinMode(BUILTIN_LED, OUTPUT);
Serial.println(F("Booting...."));
SPI.begin(); // Init SPI bus
mfrc522.PCD_Init(); // Init MFRC522
Serial.println(F("Ready!"));
Serial.println(F("======================================================"));
Serial.println(F("Scan for Card and print UID:"));
}
//======================================================
void process_mqtt() {
if (WiFi.status() == WL_CONNECTED) {
if (client.connected()) {
client.loop();
} else {
// client id, client username, client password, last will topic, last will qos, last will retain, last will message
if (client.connect(MQTTid, MQTTuser, MQTTpsw, MQTTid "/status", 2, true, "0")) {
pendingDisconnect = false;
mqttConnectedCb();
}
}
} else {
if (client.connected())
client.disconnect();
}
if (!client.connected() && !pendingDisconnect) {
pendingDisconnect = true;
mqttDisconnectedCb();
}
}
//======================================================
void loop() {
process_mqtt();
long now = millis();
if (Flash)
{
digitalWrite(BUILTIN_LED, !digitalRead(BUILTIN_LED));
delay(500);
}
if (mfrc522.PICC_IsNewCardPresent() && mfrc522.PICC_ReadCardSerial()) { // 如果出現新卡片就讀取卡片資料
delay(100);
String IDNo = printHex(mfrc522.uid.uidByte, mfrc522.uid.size);
// Show some details of the PICC (that is: the tag/card)
if ((IDNo != IDNo_buf) || (now - lastMsg > 5000)) { //不同卡片 或是 等5秒
lastMsg = now;
Serial.print(F("Card UID:"));
Serial.println(IDNo);
//Serial.println(IDNo_buf);
IDNo_buf="";
IDNo_buf=IDNo;
// Convert data to JSON string
String json =
"{\"data\":{"
"\"RFID_No\": \"" + IDNo + "\"}"
"}";
// Convert JSON string to character array
json.toCharArray(jsonChar, json.length()+1);
if (client.connected()) {
Serial.print("Publish message: ");
Serial.println(json);
// Publish JSON character array to MQTT topic
client.publish("alex9ufo/outTopic/RFID/json",jsonChar);
}
} // if ((IDNo != IDNo_buf) || (now - lastMsg > 5000))
} // if (mfrc522.PICC_IsNewCardPresent()
} //Loop
//======================================================
