#include <mcp_can.h>
#include <SPI.h>
#include <Keypad.h>
#include <LiquidCrystal_I2C.h>

const byte ROWS = 4;
const byte COLS = 4;
char keys[ROWS][COLS] = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};
byte rowPins[ROWS] = {11, 9, 8, 7};
byte colPins[COLS] = {6, 5, 4, 3};
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);
LiquidCrystal_I2C lcd(0x27, 20, 4);

MCP_CAN CAN0(10);     // Set CS to pin 10

long unsigned int rxId;
unsigned char len = 0;
unsigned char rxBuf[8];
char msgString[128];                        // Array to store serial string

#define CAN0_INT 2                              // Set INT to pin 2


void setup() {
  Serial.begin(115200);
  lcd.init();
  lcd.backlight();
  if (CAN0.begin(MCP_ANY, CAN_500KBPS, MCP_16MHZ) == CAN_OK) {
    Serial.println("MCP2515 Initialized Successfully!");
  } else {
    Serial.println("Error Initializing MCP2515...");
  }
  CAN0.setMode(MCP_NORMAL);   // Change to normal mode to allow messages to be transmitted
  pinMode(CAN0_INT, INPUT);
}

byte data[8];



void loop() {
  lcd.setCursor(0,0);
  lcd.print("A: Send message");
  lcd.setCursor(0,1);
  lcd.print("B: Receive message");
  char key1 = keypad.getKey();
    if (key1) {
      if (key1=='A'){
        send();
      }
      else if (key1=='B'){
        receive();
      }
    }
}

void displayData() {
  lcd.setCursor(0, 1);
  lcd.print(":");
  for (int i = 0; i < 8; i++) {
    lcd.print(data[i], HEX);
    lcd.print(" ");
  }
  delay(5000);
}

void send() {
 lcd.clear();
  lcd.print("Message 8 bytes:");
  lcd.setCursor(0, 1);
  
  int index = 0;
  String input = "";
  
  while (index < 8) {
    char key = keypad.getKey();
    if (key) {
      if (key == '#') {
        // Convert input to byte
        byte value = (byte) strtol(input.c_str(), NULL, 16); //Convertit une chaîne de caractères en entier
        data[index] = value;
        index++;
        input = "";
        lcd.setCursor(0, 1);
        lcd.print("                "); // Clear the input area
        lcd.setCursor(0, 1);
      } else if (key == '*') {
        // Clear current input
        input = "";
        lcd.setCursor(0, 1);
        lcd.print("                "); // Clear the input area
        lcd.setCursor(0, 1);
      } else {
        input += key;
        lcd.print(key);
      }
    }
  }
    
  byte sndStat = CAN0.sendMsgBuf(0x00, 0, 8, data); // CAN_SEND.sendMsgBuf(id, ext, len, buf);
  if (sndStat == CAN_OK) {
    lcd.setCursor(0, 0);
    lcd.print("                    ");
    lcd.setCursor(0, 0);
    lcd.print("Sent Successfully!");
    displayData();
    delay(2000);
    lcd.clear();
  } else {
    lcd.setCursor(0, 0);
    lcd.print("                    ");
    lcd.setCursor(0, 0);
    lcd.print("Error Sending...");
    displayData();
    delay(1500);
    lcd.clear();
  }
  delay(100);   // send data per 100ms
}

void receive() {
  if(!digitalRead(CAN0_INT))                         // If CAN0_INT pin is low, read receive buffer
  {
    CAN0.readMsgBuf(&rxId, &len, rxBuf);      // Read data: len = data length, buf = data byte(s) 
   //stocker l'ID du message dans rxId, la longueur des données dans len, et les données elles-mêmes dans le tableau rxBuf.
    
    if((rxId & 0x80000000) == 0x80000000)     // Le code vérifie si le message CAN a un ID étendu ou standard en regardant le bit 31 (0x80000000) de rxId. Si ce bit est défini (1), l'ID est étendu. Sinon, l'ID est standard.
      sprintf(msgString, "Extended ID: 0x%.8lX  DLC: %1d  Data:", (rxId & 0x1FFFFFFF), len);
    else
      sprintf(msgString, "Standard ID: 0x%.3lX  DLC: %1d  Data:", rxId, len);
      lcd.clear();
      lcd.print(msgString);
      delay(5000);
      lcd.clear();
  
    if((rxId & 0x40000000) == 0x40000000){    //vérifie si le message est une trame de demande distante (remote request frame)
      sprintf(msgString, " REMOTE REQUEST FRAME"); // si le bit 30=1
      lcd.setCursor(0,3);
      lcd.print(msgString);
    } else {
      for(byte i = 0; i<len; i++){
        sprintf(msgString, " 0x%.2X", rxBuf[i]);
        lcd.setCursor(0,3);
        lcd.print(msgString);
      }
    }
  }
}