TWI(I2C) ATxmega256A3 for initializing OLED Microdisplay

[Shivashankar M N]

Dear Friends

Please let know how to use the I2C (TWI) communication for initializing micro display during power on.

The Requirement is to initialize the set of 27 registers in OLED Micro display (act as slave at address 0x64) when powered ON to enable the PAL/NTSC video format.

The details of default set of values are attached in the file. Please guide me how to implement using C program for microcontroller

ATxmega256A3BU.

Datasheet of OLED microdisplay attached.



I have a code as below. Please let me know how to differentiate slave

address and registers of the slave address and data to be sent.



#include <avr/io.h>

#include "avr_compiler.h"

#include "twi_master_driver.h"

#include "twi_slave_driver.h"



/*! Defining an example slave address. */

#define SLAVE_ADDRESS    0x64



/*! Defining number of bytes in buffer. */

#define NUM_BYTES   27



/*! CPU speed 2MHz, BAUDRATE 100kHz and Baudrate Register Settings */

#define CPU_SPEED   2000000

#define BAUDRATE     100000

#define TWI_BAUDSETTING TWI_BAUD(CPU_SPEED, BAUDRATE)





/* Global variables */

TWI_Master_t twiMaster;    /*!< TWI master module. */

TWI_Slave_t twiSlave;      /*!< TWI slave module. */





/*! Buffer with test data to send.*/

uint8_t sendBuffer[NUM_BYTES] =

{0x01,0x78,0x38,0x78,0x38,0x78,0x38,0x81,0x39,0x4A,0x10,0x00,0x02,0x00,0

x80,0xC0,0x1B,0x07,0x00,0x90,0x0f,0xD8,0x0C,0x01,0x80,0x00,0xC0};





void TWIC_SlaveProcessData(void)

{

uint8_t bufIndex = twiSlave.bytesReceived;

twiSlave.sendData[bufIndex] = (~twiSlave.receivedData[bufIndex]);

}



int main(void)

{

uint8_t BufPos = 0;

// Enable internal pull-up on PC0, PC1.. Uncomment if you don't have

external pullups

PORTCFG.MPCMASK = 0x03; // Configure several PINxCTRL

registers at the same time

PORTC.PIN0CTRL = (PORTC.PIN0CTRL & ~PORT_OPC_gm) |

PORT_OPC_PULLUP_gc; //Enable pull-up to get a defined level on the

switches



/* Initialize TWI master. */

TWI_MasterInit(&twiMaster,

&TWIC,

TWI_MASTER_INTLVL_LO_gc,

TWI_BAUDSETTING);



/* Initialize TWI slave. */

TWI_SlaveInitializeDriver(&twiSlave, &TWIC,

TWIC_SlaveProcessData);

TWI_SlaveInitializeModule(&twiSlave,

SLAVE_ADDRESS,

TWI_SLAVE_INTLVL_LO_gc);



/* Enable LO interrupt level. */

PMIC.CTRL |= PMIC_LOLVLEN_bm;

sei();



TWI_MasterWriteRead(&twiMaster,        // Module

slave_reg[BufPos],                         // slave address

&sendBuffer[BufPos],                   // What to send

1,                                    // Write how much

0);                                   // Read how much



while (twiMaster.status != TWIM_STATUS_READY) {

/* Wait until transaction is complete. */

}



while(1)

{

//TODO:: Please write your application code

}

}



/*! TWIC Master Interrupt vector. */

ISR(TWIC_TWIM_vect)

{

TWI_MasterInterruptHandler(&twiMaster);

}



/*! TWIC Slave Interrupt vector. */

ISR(TWIC_TWIS_vect)

{

TWI_SlaveInterruptHandler(&twiSlave);

}

[Author]

Posts