Instantly share code, notes, and snippets.

Embed
What would you like to do?
esp32 will publish message received from serial line to mqtt broker, writes messages received from mqtt broker to serial line
#include <WiFi.h>
#include <PubSubClient.h>
// Update these with values suitable for your network.
const char* ssid = "SSID";
const char* password = "pwd";
const char* mqtt_server = "iot.eclipse.org";
#define mqtt_port 1883
#define MQTT_USER "username"
#define MQTT_PASSWORD "password"
#define MQTT_SERIAL_PUBLISH_CH "/icircuit/ESP32/serialdata/tx"
#define MQTT_SERIAL_RECEIVER_CH "/icircuit/ESP32/serialdata/rx"
WiFiClient wifiClient;
PubSubClient client(wifiClient);
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, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
randomSeed(micros());
Serial.println("");
Serial.println("WiFi connected");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
}
void reconnect() {
// Loop until we're reconnected
while (!client.connected()) {
Serial.print("Attempting MQTT connection...");
// Create a random client ID
String clientId = "ESP32Client-";
clientId += String(random(0xffff), HEX);
// Attempt to connect
if (client.connect(clientId.c_str(),MQTT_USER,MQTT_PASSWORD)) {
Serial.println("connected");
//Once connected, publish an announcement...
client.publish("/icircuit/presence/ESP32/", "hello world");
// ... and resubscribe
client.subscribe(MQTT_SERIAL_RECEIVER_CH);
} else {
Serial.print("failed, rc=");
Serial.print(client.state());
Serial.println(" try again in 5 seconds");
// Wait 5 seconds before retrying
delay(5000);
}
}
}
void callback(char* topic, byte *payload, unsigned int length) {
Serial.println("-------new message from broker-----");
Serial.print("channel:");
Serial.println(topic);
Serial.print("data:");
Serial.write(payload, length);
Serial.println();
}
void setup() {
Serial.begin(115200);
Serial.setTimeout(500);// Set time out for
setup_wifi();
client.setServer(mqtt_server, mqtt_port);
client.setCallback(callback);
reconnect();
}
void publishSerialData(char *serialData){
if (!client.connected()) {
reconnect();
}
client.publish(MQTT_SERIAL_PUBLISH_CH, serialData);
}
void loop() {
client.loop();
if (Serial.available() > 0) {
char bfr[501];
memset(bfr,0, 501);
Serial.readBytesUntil( '\n',bfr,500);
publishSerialData(bfr);
}
}
@ginodecock

This comment has been minimized.

Show comment
Hide comment
@ginodecock

ginodecock Jul 8, 2018

Hi,

It seems that it is dropping some data from the serial input.

ginodecock commented Jul 8, 2018

Hi,

It seems that it is dropping some data from the serial input.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment