TM4C Launchpad: i2c lcd from switch-science

i2c-lcd.c

#include <stdint.h>
#include <stdbool.h>
#include "inc/hw_ints.h"
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "driverlib/gpio.h"
#include "driverlib/pin_map.h"
#include "driverlib/sysctl.h"
#include "driverlib/uart.h"
#include "driverlib/i2c.h"

void initI2C(void)
{
  SysCtlPeripheralEnable(SYSCTL_PERIPH_I2C0);
  SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOB);
  
  // Set up the pins as I2C
  GPIOPinTypeI2CSCL(GPIO_PORTB_BASE, GPIO_PIN_2);
  GPIOPinTypeI2C(GPIO_PORTB_BASE, GPIO_PIN_3);
  
  GPIOPinConfigure(GPIO_PB2_I2C0SCL);
  GPIOPinConfigure(GPIO_PB3_I2C0SDA);
  
  // master enable
  I2CMasterInitExpClk(I2C0_BASE, SysCtlClockGet(), false);//false for 100kHz mode 
  I2CMasterEnable(I2C0_BASE);
}


void I2C_byte(unsigned char slave_address, unsigned char data) {
  
  volatile int i = 0;
  
  // start I2C transmit
  I2CMasterSlaveAddrSet(I2C0_BASE, slave_address, false);
  I2CMasterDataPut(I2C0_BASE, data);  
  while(I2CMasterBusy(I2C0_BASE)) {} // Check, the bus isn't busy (low?)
  
  // Single Byte
  I2CMasterControl(I2C0_BASE, I2C_MASTER_CMD_SINGLE_SEND);    
  while(I2CMasterBusy(I2C0_BASE)) {}    //wait
  
}

void I2C_write(unsigned char slave_address, unsigned char *data, unsigned long length)
{
  volatile int i = 0;
  
  if (length == 1) {
    I2C_byte(slave_address, *(data));
    return;
  }
  
  // start I2C transmit
  I2CMasterSlaveAddrSet(I2C0_BASE, slave_address, false);
  I2CMasterDataPut(I2C0_BASE, *(data));  
  while(I2CMasterBusy(I2C0_BASE)) {} // Check, the bus isn't busy (low?)
  // Multi Bytes
  I2CMasterControl(I2C0_BASE, I2C_MASTER_CMD_BURST_SEND_START);
  while(I2CMasterBusy(I2C0_BASE)) {} // delay until complete
  
  for(i=1; i < length; i++) {
    I2CMasterDataPut(I2C0_BASE, *(data+i));
    I2CMasterControl(I2C0_BASE, I2C_MASTER_CMD_BURST_SEND_CONT);
    while(I2CMasterBusy(I2C0_BASE)) {}    //wait
  }
  
  I2CMasterControl(I2C0_BASE, I2C_MASTER_CMD_BURST_SEND_FINISH);
  while(I2CMasterBusy(I2C0_BASE)) {} // delay until complete
  
  
}

unsigned char AQCM0802_addr = 0x3e; 
unsigned char mode;
unsigned char contrast = 0; // 0-63
unsigned char contrastFlag = false;
int CGcounter;
int FADEcounter;

void lcd_cmd(char x) {
  unsigned char data[2];
  data[0] = 0x00; // CO = 0,RS = 0
  data[1] = x;
  I2C_write(AQCM0802_addr, data, 2);
}

void lcd_contdata(char x) {
  unsigned  char data[2];
  data[0] = 0xC0; //0b11000000 CO = 1, RS = 1
  data[1] = x;
  I2C_write(AQCM0802_addr, data, 2);
}

void lcd_lastdata(char x) {
  unsigned char data[2];
  data[0] = 0x40; //0b11000000 CO = 0, RS = 1
  data[1] = x;
  I2C_write(AQCM0802_addr, data, 2);
}

void lcd_printStr(const char *s) {
  while(*s) {
    if(*(s)) {
//    if(*(s+1)) {  // origin from switch-science mag : http://mag.switch-science.com/2013/07/17/i2c-lcd-breakout/ , but duplicate print last charactor!
      lcd_contdata(*s);
    } else {
      lcd_lastdata(*s);
    }
    s++;
  }
} 

void lcd_printHex(unsigned char num) {
  lcd_contdata(num);
  lcd_lastdata(' ');
}


void lcd_clear()
{
  
  lcd_cmd(0x01); // Clear Display
  //wait(0.2);
  SysCtlDelay(10000);
}

void lcd_init() {
  // wait(0.04);
  SysCtlDelay(400000);
  
  // LCD initialize
  lcd_cmd(0x38); // function set
  lcd_cmd(0x39); // function set
  lcd_cmd(0x04); // EntryModeSet
  lcd_cmd(0x14); // interval osc
  lcd_cmd(0x70 | (contrast & 0xF)); // contrast Low
  lcd_cmd(0x5C | ((contrast >> 4) & 0x3)); // contast High/icon/power
  lcd_cmd(0x6C); // follower control
  //wait(0.2);
  SysCtlDelay(2000000);
  
  lcd_cmd(0x38); // function set
  lcd_cmd(0x0C); // Display On
  lcd_clear();
}

void lcd_setContrast(unsigned char c) {
  lcd_cmd(0x39);
  lcd_cmd(0x70 | (c & 0x0f)); // contrast Low
  lcd_cmd(0x5C | ((c >> 4) & 0x03)); // contast High/icon/power
  lcd_cmd(0x38);
}


void lcd_setCursor(unsigned char x,unsigned char y) {
  lcd_cmd(0x80 | (y * 0x40 + x));
}

char* itoa(int i, char b[]){
  char const digit[] = "0123456789";
  char* p = b;
  if(i<0){
    *p++ = '-';
    i *= -1;
  }
  int shifter = i;
  do{ //Move to where representation ends
    ++p;
    shifter = shifter/10;
  }while(shifter);
  *p = '\0';
  do{ //Move back, inserting digits as u go
    *--p = digit[i%10];
    i = i/10;
  }while(i);
  return b;
}

int main () {
  char buffer[8];
  initI2C();
  
  lcd_init();
  lcd_setContrast(30);
  
  while(1) {
    for (int i = 100;i >= 0;i--) {
      lcd_setCursor(0, 0);
      lcd_printStr("TimeBoom");
      lcd_setCursor(0, 1);
      lcd_printStr(itoa(i,buffer));
      SysCtlDelay(10000000);
      lcd_clear();
    }
  }
}

fix to send last byte twice.

Need to test!

void lcd_cmd(char x) {
unsigned char data[3];
data[0] = 0x00; // CO = 0,RS = 0
data[1] = x;
data[1] = 0x00;
I2C_write(AQCM0802_addr, data, 3);
}

void I2C_write(unsigned char slave_address, unsigned char *data, unsigned long length)
{
  volatile int i = 0;
  
  if (length == 1) {
    I2C_byte(slave_address, *(data));
    return;
  }
  
  // start I2C transmit
  I2CMasterSlaveAddrSet(I2C0_BASE, slave_address, false);
  I2CMasterDataPut(I2C0_BASE, *(data));  
  while(I2CMasterBusy(I2C0_BASE)) {} // Check, the bus isn't busy (low?)
  // Multi Bytes
  I2CMasterControl(I2C0_BASE, I2C_MASTER_CMD_BURST_SEND_START);
  while(I2CMasterBusy(I2C0_BASE)) {} // delay until complete
  
  for(i=1; i < length-1; i++) {
    I2CMasterDataPut(I2C0_BASE, *(data+i));
    I2CMasterControl(I2C0_BASE, I2C_MASTER_CMD_BURST_SEND_CONT);
    while(I2CMasterBusy(I2C0_BASE)) {}    //wait
  }

  I2CMasterDataPut(I2C0_BASE, *(data+length-1));
  I2CMasterControl(I2C0_BASE, I2C_MASTER_CMD_BURST_SEND_FINISH);
  while(I2CMasterBusy(I2C0_BASE)) {} // delay until complete
  
  
}