group assignment:

      send a message between two projects

 

https://fabacademy.org/2022/labs/ciudadmexico/embedded-networking-and-communications.html

 

 

individual assignment:

      design, build, and connect wired or wireless node(s)

      with network or bus addresses

 

For this work I designed a card based on my original Josanino but I included a button and a led in addition to connecting the Atmel processor to the Two Wire Interface (TWI ) pins or also known as I2C which would be SDA (PA14) and SCL (PA15). Said pins are digital and will also help us to connect and program it with another card

The I2C is an inter-integrated controller. This is a serial communication protocol that can connect low-speed devices. It is a master-slave communication in which we can connect and control multiple secondaries from a single master. The I2C bus transmits data and clock with SDA and SCL.

For more specific information about I2C you can consult the following links

 

https://www.i2c-bus.org/i2c-primer/how-i2c-hardware-works/

 

https://content.arduino.cc/assets/Nano-Every_USB-Serial_Atmel-42363-SAM-D11_Datasheet.pdf

 

   Download File

We verify that the MDX 20 model machine is selected and we assign the origin right at the corner of our plate placed on the machine, which in this case was the coordinate x=20 y=20. We turn on the first button and press the open port button so that the machine makes the correct connection to machine the PCB board.

Board ready and with all the components already soldered

Button

We open the arduino software and in the tools menu we select the port with which it recognized our card COM13 (MattaiTech Xeno Mini)

The PCB designed by me was used as Master and another PCB from FABLAB as Secondary. In the arduino software, the programming of each of them is loaded and activated with the Serial Monitor. In this case, a boozer with the letter A is turned on and off with the letter S.

Master

#include <Wire.h> // Include the networking library.

//char c;

int led = 5;

void setup()

{

Serial.begin(115200); // Open the serial port

Wire.begin(); // It is not necessary to declare an address for the main board.

pinMode(4, OUTPUT); // This is the main board output.

pinMode(led, OUTPUT);

}

 

void loop()

{

digitalWrite(led, HIGH);

 

while (Serial.available())

{

char c = Serial.read(); // Read the character written through the serial monitor.

 

if (c == 'A')

{

//digitalWrite(led, HIGH);

Wire.beginTransmission(2); // This is a secondary board with address 2.

Wire.write('A');

Wire.endTransmission();

Serial.println("writing to address 2!");

}

 

if (c == 'S')

{

//digitalWrite(led, LOW);

Wire.beginTransmission(2); // This is a secondary board with address 2.

Wire.write('S');

Wire.endTransmission();

Serial.println("stop to address 2!");

    }

  }

}

 

Secondary

#include <Wire.h> // This is the library we will be using to allow the board to understand networking instructions.

 

byte own_address = 2; // This is the address assigned to the board, it will be used to differentiate it from the other boards.

int i = 0;

 

 

void setup()

{

Serial.begin(115200);

Wire.begin(own_address); // Declare that this is the board called by a certain address.

 

Wire.onReceive(receiveEvent); // Instruct what to do when receiving information.

 

pinMode(4, OUTPUT); //

pinMode(2, OUTPUT);

 

//digitalWrite(4, LOW); //

//digitalWrite(2, HIGH); //

}

 

void loop()

{

}

 

void receiveEvent(int howMany) // What to do when receiving information.

{

while (Wire.available()) // While it is being called.

{

char c = Wire.read(); // Read the character sent by the main board.

if(c == 'A') //

{

  digitalWrite(2, HIGH);

 

    i = 0;

    do

    {

      digitalWrite(4, HIGH);

      delay(500);

      digitalWrite(4, LOW);

      delay(500);

      i++;

    } while (i < 10);;

 

}

if (c == 'S')

{

  digitalWrite(2, LOW);

    }

  }

}

 

 

The program is executed correctly since, as indicated by the programming, the LED turns on and off after a few seconds