Hello, I got my node-red flow connected with mqtt broker to switch relays with my weimos d1 mini and modbus relay board. When upload my code to esp8266 it doesn't show anything on my serial port COM4 - 115200 : It should show if it connected correctly to my WIFI etc and everything written in my code, but it doesn't and my relays doesn't switch too haha 
weimos d1 mini code:
#ifdef ESP8266
#include <ESP8266WiFi.h>
#elif defined(ESP32)
#include <WiFi.h>
#else
#error "Board not found"
#endif
#include <PubSubClient.h>
#include <ModbusRTU.h>
#define SLAVE_ID 2
#define Relay1 0x001
#define Relay2 0x002
#define Relay3 0x003
#define Relay4 0x004
#define Relay5 0x005
#define Relay6 0x006
#define Relay7 0x007
#define Relay8 0x008
#if defined(ESP8266)#include <SoftwareSerial.h>
// SoftwareSerial S(D1, D2, false, 256);
// receivePin, transmitPin, inverse_logic, bufSize, isrBufSize
// connect RX to D2 (GPIO4, Arduino pin 4), TX to D1 (GPIO5, Arduino pin 4)
SoftwareSerial S(3, 1); // 3 - RX, 1 - TX Wemos D1 Mini
#endif
int DE_RE = 5; // For MAX485 chip
ModbusRTU mb;
bool cbWrite(Modbus::ResultCode event, uint16_t transactionId, void * data) {
#ifdef ESP8266
Serial.printf_P("Request result: 0x%02X, Mem: %d\n", event, ESP.getFreeHeap());
#else
Serial.print("Request result: 0x");
Serial.print(event, HEX);
#endif
return true;
}
// NETWORK CONNECTION
const char * ssid = "xx";
const char * password = "xxxxx";
const char * mqtt_server = "7e2xxxxxxxxxxxxx71a.s1.eu.hivemq.cloud"; // Local IP address of Raspberry Pi or cloud mqtt broker
const char * username = "xxxxxxxxxx";
const char * pass = "xxxxxxxxxxxxxxx";
// Subscribed Topics
#define sub1 "device1/relay1"
#define sub2 "device1/relay2"
#define sub3 "device1/relay3"
#define sub4 "device1/relay4"
#define sub5 "device1/relay5"
#define sub6 "device1/relay6"
#define sub7 "device1/relay7"
#define sub8 "device1/relay8"
WiFiClient espClient;
PubSubClient client(espClient);
unsigned long lastMsg = 0;
#define MSG_BUFFER_SIZE(50)
char msg[MSG_BUFFER_SIZE];
int value = 0;
// Connecting to WiFi Router
void setup_wifi() {
delay(10);
// We start by connecting to a WiFi network
Serial.println();
Serial.print("Connecting to ");
Serial.println(ssid);
WiFi.mode(WIFI_STA);
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 callback(char * topic, byte * payload, unsigned int length) {
Serial.print("Message arrived [");
Serial.print(topic);
Serial.print("] ");
if (!mb.slave()) {
if (strstr(topic, sub1)) {
for (int i = 0; i < length; i++) {
Serial.print((char) payload[i]);
}
Serial.println();
// Switch on the LED if an 1 was received as first character
if ((char) payload[0] == '1') {
mb.writeHreg(SLAVE_ID, 0x0001, 0x0100, cbWrite); // 0x001 - relay 1, 0x002 - relay 2 and so on
// 0x0100 - turn on relay, 0x0200 turn off relay
} else {
mb.writeHreg(SLAVE_ID, 0x0001, 0x0200, cbWrite); // turn off the light
}
} else if (strstr(topic, sub2)) {
for (int i = 0; i < length; i++) {
Serial.print((char) payload[i]);
}
Serial.println();
// Switch on the light if an 1 was received as first character
if ((char) payload[0] == '1') {
mb.writeHreg(SLAVE_ID, 0x0002, 0x0100, cbWrite);
} else {
mb.writeHreg(SLAVE_ID, 0x0002, 0x0200, cbWrite); // turn off the light
}
} else if (strstr(topic, sub3)) {
for (int i = 0; i < length; i++) {
Serial.print((char) payload[i]);
}
Serial.println();
// Switch on the light if an 1 was received as first character
if ((char) payload[0] == '1') {
mb.writeHreg(SLAVE_ID, 0x0003, 0x0100, cbWrite);
} else {
mb.writeHreg(SLAVE_ID, 0x0003, 0x0200, cbWrite); // turn off the light
}
} else if (strstr(topic, sub4)) {
for (int i = 0; i < length; i++) {
Serial.print((char) payload[i]);
}
Serial.println();
// Switch on the light if an 1 was received as first character
if ((char) payload[0] == '1') {
mb.writeHreg(SLAVE_ID, 0x0004, 0x0100, cbWrite);
} else {
mb.writeHreg(SLAVE_ID, 0x0004, 0x0200, cbWrite); // turn off the light
}
} else if (strstr(topic, sub5)) {
for (int i = 0; i < length; i++) {
Serial.print((char) payload[i]);
}
Serial.println();
// Switch on the light if an 1 was received as first character
if ((char) payload[0] == '1') {
mb.writeHreg(SLAVE_ID, 0x0005, 0x0100, cbWrite);
} else {
mb.writeHreg(SLAVE_ID, 0x0005, 0x0200, cbWrite); // turn off the light
}
} else if (strstr(topic, sub6)) {
for (int i = 0; i < length; i++) {
Serial.print((char) payload[i]);
}
Serial.println();
// Switch on the light if an 1 was received as first character
if ((char) payload[0] == '1') {
mb.writeHreg(SLAVE_ID, 0x0006, 0x0100, cbWrite);
} else {
mb.writeHreg(SLAVE_ID, 0x0006, 0x0200, cbWrite); // turn off the light
}
} else if (strstr(topic, sub7)) {
for (int i = 0; i < length; i++) {
Serial.print((char) payload[i]);
}
Serial.println();
// Switch on the light if an 1 was received as first character
if ((char) payload[0] == '1') {
mb.writeHreg(SLAVE_ID, 0x0007, 0x0100, cbWrite);
} else {
mb.writeHreg(SLAVE_ID, 0x0007, 0x0200, cbWrite); // turn off the light
}
} else if (strstr(topic, sub8)) {
for (int i = 0; i < length; i++) {
Serial.print((char) payload[i]);
}
Serial.println();
// Switch on the light if an 1 was received as first character
if ((char) payload[0] == '1') {
mb.writeHreg(SLAVE_ID, 0x0008, 0x0100, cbWrite);
} else {
mb.writeHreg(SLAVE_ID, 0x0008, 0x0200, cbWrite); // turn off the light
}
} else {
Serial.println("unsubscribed topic");
}
}
mb.task();
yield();
}
// Connecting to MQTT broker
void reconnect() {
// Loop until we're reconnected
while (!client.connected()) {
Serial.print("Attempting MQTT connection...");
// Create a random client ID
String clientId = "ESP8266Client-";
clientId += String(random(0xffff), HEX);
// Attempt to connect
if (client.connect(clientId.c_str(), username, pass)) {
Serial.println("connected");
// Once connected, publish an announcement...
client.publish("outTopic", "hello world");
// ... and resubscribe
client.subscribe(sub1);
client.subscribe(sub2);
client.subscribe(sub3);
client.subscribe(sub4);
client.subscribe(sub5);
client.subscribe(sub6);
client.subscribe(sub7);
client.subscribe(sub8);
} else {
Serial.print("failed, rc=");
Serial.print(client.state());
Serial.println(" try again in 5 seconds");
// Wait 5 seconds before retrying
delay(5000);
}
}
}
void setup() {
Serial.begin(115200);
#if defined(ESP8266)
S.begin(9600, SWSERIAL_8N1);
mb.begin( & S, DE_RE);
mb.master();
#endif
setup_wifi();
client.setServer(mqtt_server, 8883);
client.setCallback(callback);
}
void loop() {
if (!client.connected()) {
reconnect();
}
client.loop();
}
What is it fault in my code? ;/
edit: I clicked the reset button on weimos d1 mini board and opened COM4 and give 115200 and then I got these weird letters /
