In this project, I am going to demonstrate how you can send and receive messages wirelessly, with the help of two idIoTware shields. No internet no worries we have some crazy idea to make a chat room that can work till few miles with the external antenna. There are many places where you can not get network. What we have done is create the large range chat room for 6 peoples.All this is possible with an Arduino, idIoTware shield and the Wireless module nRF24L01.

This Arduino Chat Room uses nRF24L01 to set up a low-cost Chat Room in your local area.You can extend the chat coverage by using nrf24l01 radio module with an external antenna.

Step 1: Requirements

Arduino UNO & Genuino UNO × 2

idIoTware Shield × 2 (https://goo.gl/D2EOdO)

NRF24L01 NRF24L01+ Wireless Module × 2

0.96" I2C oled display × 2

Generic Jumper (0.1") × 2

USB-A to B Cable × 2

9V 1A Switching Wall Power Supply × 2

Arduino IDE Installed on a computer

Step 2: Working

In this example, we are using NRF24L01 radio module and Arduino to communicate to the other Arduino and Nrf24L01 radio module using the serial monitor.

Here we are creating a local mesh between two radio modules(Nrf24L01). The two sets of Arduino and nRF24L01 are connected together to establish a wireless Serial communication link so that they could talk to each other. The nRF24L01 are half duplex transceiver modules, hence they can send and receive data. The data is sent from the user using Arduino Serial monitor, by typing on his keyboard, and this data can be received and displayed on the receivers OLED display, which is on the Idiotware shield, and vice- a verse. This project is limited to just adding two members to the Chat room, But the nRF24L01 has capability to handle 6 connections, and so there could be a maximum of 6 members in our chat room, each talking or chatting with each other. This chat room coverage could be upto 100 meters depending upon the nRF24L01 Modules range.

Step 3: Setup NRF Module

Connect the NRF module to NRF24L01 header

Step 4: Connect OLED

Connect i2c OLED on the headers above the touchpad

Step 5: Connect Buzzer

Connect the BUZ pin to the center pin on SEL13 pin header, effectively connecting the Buzzer to the A1 pin.

Step 6: Upload the Code

Upload the code from Arduino ide and start chatting with friends in neighbourhood.Use the Serial monitor of arduino ide to send message.

No more connecting things on breadboard and messy wiring. With the idIoTware shield the sky's the limit.

Step 7: Sender Code

/*

In this example we are using NRF24L01 radio and Arduino to communicate with other Arduino and NRF24L01 using Serial Monitor. Here we are creating a local mesh between two radios(NRF24L01) using and .

*/

#include #include #include #include "U8glib.h" // // Hardware configuration /

/ Set up nRF24L01 radio on SPI bus plus pins 9 & 10

RF24 radio(7,8);

// Network uses that radio RF24Network network(radio);

// Address of our node const uint16_t this_node = 0;

// Address of the other node const uint16_t other_node = 1;

boolean send_message = false; char messageToSend[32] = "";

int melody[]= {2000,2000,2000,2000}; // note durations: 4 = quarter note, 8 = eighth note, etc.: int noteDurations[] = { 8,8,8,8 };

U8GLIB_SSD1306_128X64 u8g(U8G_I2C_OPT_NONE|U8G_I2C_OPT_DEV_0); // I2C / TWI

String inputString = ""; // a string to hold incoming data boolean stringComplete = false; // whether the string is complete

void setup(void) { u8g.setFont(u8g_font_unifont); Serial.begin(57600); Serial.println("NRF24L01 MESSENGER"); SPI.begin(); radio.begin(); network.begin(/*channel*/ 90, /*node address*/ this_node); u8g.firstPage(); do { u8g.setPrintPos(0, 10); u8g.print("Organizer " ); u8g.setPrintPos(45, 10); // u8g.print(this_node); } while( u8g.nextPage() ); }

void loop() { // Pump the network regularly network.update(); if (stringComplete) // if there is typed message on serial monitor ready to send { inputString.replace("\r",""); inputString.replace("\n",""); RF24NetworkHeader header1(/*to node*/ other_node); boolean message = network.write(header1, inputString.c_str(), 32); // send message to other user if (message) { Serial.print("Organizer: "); // print message on serial monitor Serial.println( inputString); send_message = false; } else Serial.println("could not write....\n"); // if it is failed to send message prompt error stringComplete=false; inputString=""; } //// Is there anything ready for us? while (network.available() ) { // If so, grab it and print it out RF24NetworkHeader header; char messageToRecieve[32] = ""; boolean recieve = false; while (!recieve) { recieve = network.read(header, messageToRecieve ,32); Serial.print("Organizer: "); // print recived data on serial monitor Serial.println(messageToRecieve); for(int thisNote = 0; thisNote < 4; thisNote++) { // to calculate the note duration, take one second divided by the note type. //e.g. quarter note = 1000 / 4, eighth note = 1000/8, etc. int noteDuration = 1000/noteDurations[thisNote]; tone(A1, melody[thisNote],noteDuration); // to distinguish the notes, set a minimum time between them. // the note's duration + 30% seems to work well: int pauseBetweenNotes = noteDuration * 1.60; delay(pauseBetweenNotes); // stop the tone playing: noTone(8); } u8g.firstPage(); do { u8g.drawStr(0,10, "participant :"); u8g.setPrintPos(0, 30); u8g.print(messageToRecieve); } while( u8g.nextPage() ); } } } void serialEvent() { while (Serial.available()) { // get the new byte: char inChar = (char)Serial.read(); // add it to the inputString: inputString += inChar; // if the incoming character is a newline, set a flag // so the main loop can do something about it: if (inChar == '\n') { stringComplete = true; } } }

Step 8: Receiver Code

/*

In this example we are using NRF24L01 radio and Arduino to communicate with other Arduino and NRF24L01 using Serial Monitor. Here we are creating a local mesh between two radios(NRF24L01) using and .

*/

#include #include #include #include "U8glib.h" // // Hardware configuration /

/ Set up nRF24L01 radio on SPI bus plus pins 9 & 10

RF24 radio(7,8);

// Network uses that radio RF24Network network(radio);

// Address of our node const uint16_t this_node = 1;

// Address of the other node const uint16_t other_node = 0;

boolean send_message = false; char messageToSend[32] = ""; //

int melody[]= {2000,2000,2000,2000}; // note durations: 4 = quarter note, 8 = eighth note, etc.: int noteDurations[] = { 8,8,8,8 };

U8GLIB_SSD1306_128X64 u8g(U8G_I2C_OPT_NONE|U8G_I2C_OPT_DEV_0); // I2C / TWI

String inputString = ""; // a string to hold incoming data boolean stringComplete = false; // whether the string is complete

void setup(void) { u8g.setFont(u8g_font_unifont); Serial.begin(57600); Serial.println("NRF24L01 MESSENGER"); SPI.begin(); radio.begin(); network.begin(/*channel*/ 90, /*node address*/ this_node); u8g.firstPage(); do { u8g.setPrintPos(0, 10); u8g.print("Participant " ); u8g.setPrintPos(45, 10); // u8g.print(this_node); } while( u8g.nextPage() ); }

void loop() { // Pump the network regularly network.update(); if (stringComplete) // if there is typed message on serial monitor ready to send { inputString.replace("\r",""); inputString.replace("\n",""); RF24NetworkHeader header1(/*to node*/ other_node); boolean message = network.write(header1, inputString.c_str(), 32); // send message to other user if (message) { Serial.print("Participant: "); // print message on serial monitor Serial.println(inputString); send_message = false; } else Serial.println("could not write....\n"); // if it is failed to send message prompt error stringComplete=false; inputString=""; } // Is there anything ready for us? while (network.available() ) { // If so, grab it and print it out RF24NetworkHeader header; char messageToRecieve[32] = ""; boolean recieve = false; while (!recieve) { recieve = network.read(header, messageToRecieve , 32 ); Serial.print("Participant: "); // print recived data on okserial monitor Serial.println(messageToRecieve); for(int thisNote = 0; thisNote < 4; thisNote++) { // to calculate the note duration, take one second divided by the note type. //e.g. quarter note = 1000 / 4, eighth note = 1000/8, etc. int noteDuration = 1000/noteDurations[thisNote]; tone(A1, melody[thisNote],noteDuration); // to distinguish the notes, set a minimum time between them. // the note's duration + 30% seems to work well: int pauseBetweenNotes = noteDuration * 1.60; delay(pauseBetweenNotes); // stop the tone playing: noTone(8); } u8g.firstPage(); do { u8g.drawStr(0,10, "Organizer : "); u8g.setPrintPos(0, 30); u8g.print(messageToRecieve); } while( u8g.nextPage() ); } } } void serialEvent() { while (Serial.available()) { // get the new byte: char inChar = (char)Serial.read(); // add it to the inputString: inputString += inChar; // if the incoming character is a newline, set a flag // so the main loop can do something about it: if (inChar == '\n') { stringComplete = true; } } }