I am trying to program arduino's atmega328p serial communication registers myself. After referring to several resources on the internet I have arrived at the following code:

#define BAUDRATE(BAUD) (((F_CPU/(BAUD*16UL)))-1)
    class serials
    {
              serials()
        {
            UBRR0H = BAUDRATE(9600) >> 8;
            UBRR0L = BAUDRATE(9600);

            UCSR0B = _BV(TXEN0) | _BV(RXEN0) | _BV(TXCIE0);
            UCSR0C = _BV(UCSZ01) | _BV(UCSZ00);
        }
        void transmit(unsigned char);
};
void serials::transmit(unsigned char data)
    {
           
              while(!(UCSR0A & _BV(UDRE0)));
                  UDR0 = data;
                    
       
           
    }

void loop()
{
serials lcdtransmit;

  lcdtransmit.transmit(254);
  lcdtransmit.transmit(1);
  lcdtransmit.transmit(254);
  lcdtransmit.transmit(128);
  lcdtransmit.transmit('a');
while(1);
}

I am trying to transmit 'a' to a serial lcd. Though the serial lcd displays 'a', the data on the lcd resets continuously.
Is there any solution to this issue ? Is there any error in the code written.
Is this problem specific to arduino.

 

Do you have Arduino board?
What model of Arduino board do you have?

 

Do you have Arduino board?
What model of Arduino board do you have?

Arduino uno

 

Arduino uno

Your code does not look like Arduino code. It looks like pure C. See if this will help you move C code to Uno: https://balau82.wordpress.com/2011/03/29/programming-arduino-uno-in-pure-c/

 

Hi TheBeginner:

Your code looks similar to the code in my very first Arduino program from six or seven weeks ago. My code worked fine using a terminal app' on my PC.

You might add comments to your 'loop' section. Can I assume you're sending a '254' character ahead of each LCD 'command' character? In this case you're sending a 0x01 (clear screen) command and a 0x80 (set DDRAM address) command?

Regards, Mike

/*******************************************************************
 *                                                                 *
 *     Project: UART_Echo                                          *
 *      Author: Mike McLaren, K8LH                                 *
 *        Date: 28-Apr-16                                          *
 *                                                                 *
 *   Arduino Nano USART Echo Test (9600 baud) tries to avoid       *
 *   using Arduino core function calls.                            *
 *                                                                 *
 *       Board: Arduino Nano                                       *
 *         IDE: Arduino 1.6.8                                      *
 *                                                                 *
 *******************************************************************/

 #include <avr/io.h>

//#define F_CPU 16000000UL          // provided by boards.txt

/*******************************************************************
 *  constants & helper macros                                      *
 *******************************************************************/

 #define _BAUD    9600                 // baud rate
 #define _UBRR    (F_CPU/16)/_BAUD-1

 #define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~(1<<bit))
 #define sbi(sfr, bit) (_SFR_BYTE(sfr) |= 1<<bit)

/*******************************************************************
 *  variables                                                      *
 *******************************************************************/
/*******************************************************************
 *  functions                                                      *
 *******************************************************************/

 char usart_GetSer(void)            // GetSer (blocking)
 { while(!(UCSR0A & 1<<RXC0));      // wait char available 
   return UDR0;                     //
 }                                  //
/*******************************************************************/
 void usart_PutSer(char data)       // PutSer (blocking)
 { while(!(UCSR0A & 1<<UDRE0));     //
     UDR0 = data;                   //
 }                                  //
/*******************************************************************/
 void usart_PutStr(char * data)     // PutStr
 { while(*data!=0)                  //
     usart_PutSer(*data++);         //
 }                                  //
/*******************************************************************/
 void usart_PutNib(char work)       // PutNib (hex nibble to ASCII)
 { work &= 0x0F;                    // lo nibble only
   if(work > 9) work += 7;          // 'A'..'F' values
   usart_PutSer(work + '0');        // put ascii nibble
 }                                  //
/*******************************************************************/
 void usart_PutHex(char value)      // PutHex
 { usart_PutNib(value >> 4);        //
   usart_PutNib(value);             //
 }                                  //

/*******************************************************************
 *  main setup                                                     *
 *******************************************************************/
 int main (void)                    //
 { UBRR0H = (_UBRR) >> 8;           // setup USART port
   UBRR0L = (_UBRR);                //  "
 //UCSR0B |= _BV(TXEN0);            //  "
 //UCSR0B |= _BV(RXEN0);            //  "
 //sbi(UCSR0B, TXEN0);              //  "
 //sbi(UCSR0B, RXEN0);              //  "
   UCSR0B |= 1<<TXEN0 | 1<<RXEN0;   //  "

 //usart_PutStr("Hello world ");    // test
 //usart_PutHex(0x3C);              // test
 //usart_PutSer(' ');               // test

/*******************************************************************
 *  main loop                                                      *
 *******************************************************************/
   while(1)                         //
   { usart_PutSer(usart_GetSer());  // echo to terminal
   }                                //
 }                                  //