Another LEGO EV3 to NXT mindstorms communication solution

#include <Wire.h>
#include <Wire1.h>
#define SLAVE_ADDRESS 0x54 // decimal 84 for EV3: decimal 168 for NXT
// This program will only work on microcontolers with 2 or more I2C ports like: Atmega328PB or Teensy 3.2
// The microcontroller must be able to work with 5V power supply and 5V tolerant inputs/outputs
// both I2C port  need to have 4k7 pullup resitors on SDA and SCL

// Lego EV3 or NXT wil send:
// Boolean write: ramaddress, number of bytes, one data byte    (number = 0) howmany =3
// Boolean read: ramaddress, number of bytes                    (number = 1) howmany =2
// Numeric write: ramaddress, number of bytes, four data bytes  (number = 0) howmany =6
// Numeric read: ramaddress, number of bytes                    (number = 4) howmany =2
// The combination of howmany bytes received and number of bytes,
// makes it possible to know:
// If data is written or read and howmany bytes to send back to EV3 or NXT.

//reserve 256 of memory
byte ram[256];

// variables wire or port 0
byte howMany = 0;
byte num = 0;
byte addr = 0;
byte buf[6] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00};

//variables wire1 or port1
byte howmany1 = 0;
byte num1 = 0;
byte addr1 = 0;
byte buf1[6] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00};

void setup() {
  Wire.begin(SLAVE_ADDRESS);
  Wire.onReceive(receiveEvent);
  Wire.onRequest(requestEvent);

  Wire1.begin(SLAVE_ADDRESS);
  Wire1.onReceive(receiveEvent1);
  Wire1.onRequest(requestEvent1);
}

void loop() {}


void receiveEvent(byte howMany) // receive howMany bytes data from master
{
  int j = 0;
  while (Wire.available()) {
    buf[j] = Wire.read();
    j = j + 1;
    if (j > howMany) j = 0;
  }
  addr = buf[0]; //ram address
  num = buf[1]; // number of bytes to send back to master
  switch (num)
  {
    case 0:
      if (howMany == 6)
      {
        ram[addr] = buf[2];
        ram[addr + 1] = buf[3];
        ram[addr + 2] = buf[4];
        ram[addr + 3] = buf[5];
      }
      else
      {
        ram[addr] = buf[2];
       }
      break;
    case 1:
      buf[2] = ram[addr];
      break;
    case 4:
      buf[2] = ram[addr];
      buf[3] = ram[addr + 1];
      buf[4] = ram[addr + 2];
      buf[5] = ram[addr + 3];
      break;
    default:
      // statements
      break;
  }
}

void receiveEvent1(byte howMany1) // receive howMany bytes data from master
{
  int j1 = 0;
  while (Wire1.available()) {
    buf1[j1] = Wire1.read();
    j1 = j1 + 1;
    if (j1 > howMany1) j1 = 0;
  }
  addr1 = buf1[0];
  num1 = buf1[1];
    
  switch (num1)
  {
    case 0:
      if (howMany1 == 6)
      {
        ram[addr1] = buf1[2];
        ram[addr1 + 1] = buf1[3];
        ram[addr1 + 2] = buf1[4];
        ram[addr1 + 3] = buf1[5];
      }
      else
      {
        ram[addr1] = buf1[2];
      }
      break;
    case 1:
      buf1[2] = ram[addr1];
      break;
    case 4:
      buf1[2] = ram[addr1];
      buf1[3] = ram[addr1 + 1];
      buf1[4] = ram[addr1 + 2];
      buf1[5] = ram[addr1 + 3];
      break;
    default:
      // statements
      break;
  }

}

// The address and size is also send, this makes my program simpler
// These first 2 bytes are not used in the EV3 or NXT

void requestEvent() {
  buf[2] = ram[addr];
  buf[3] = ram[addr + 1];
  buf[4] = ram[addr + 2];
  buf[5] = ram[addr + 3];

  if (num == 4)
  {
    Wire.write(buf, 6); // send 6 data bytes to master, EV3 reverses I2C receive buffer
  }
  else
  {
    Wire.write(buf, 3); // send 3 date bytes to master
  }
}

void requestEvent1() {
  buf1[2] = ram[addr1];
  buf1[3] = ram[addr1 + 1];
  buf1[4] = ram[addr1 + 2];
  buf1[5] = ram[addr1 + 3];

  if (num1 == 4)  {
    Wire1.write(buf1, 6); // send 6 data bytes to master, EV3 reverses I2C receive buffer
  }
  else
  {
    Wire1.write(buf1, 3); // send 3 data bytes to master
  }
}