Self-Calibrating USB Voltage/Current Meter

// Instructions
#define TM_DATA_CMD             0x40
#define TM_DISP_CTRL            0x80
#define TM_ADDR_CMD             0xC0

// Data command set
#define TM_WRITE_DISP           0x00
#define TM_READ_KEYS            0x02
#define TM_FIXED_ADDR           0x04

// Display control command
#define TM_DISP_PWM_MASK        0x07 // First 3 bits are brightness (PWM controlled)
#define TM_DISP_ENABLE          0x08


#include "TTM1637.h"


/* UNCOMMENT UNUSED CHARACTERS IF YOU WANT TO USE IT ON ANOTHER PROJECT*/
 const uint8_t FLASH_DIR TM_DIGITS[] =
{
    0x3F, // 0
    0x06, // 1
    0x5B, // 2
    0x4F, // 3
    0x66, // 4
    0x6D, // 5
    0x7D, // 6
    0x07, // 7
    0x7F, // 8
    0x6F, // 9

//    0x77, // A
//    0x7C, // b
//	  0x39, // C
//    0x5E, // d
//    0x79, // E
//    0x71, // F
//
//
//    0x3D, // G
//    0x76, // H
//    0x06, // I
//    0x1F, // J
//    0x76, // K 
//    0x38, // L
//    0x15, // M
//    0x54, // n
//    0x3F, // O
//    0x73, // P
//    0x67, // Q
//    0x50, // r
//    0x6D, // S
//    0x78, // t
//    0x3E, // U
//    0x1C, // V
//    0x2A, // W
//    0x76, // X 
//    0x6E, // Y
//    0x5B  // Z
};




void TM_PortInit()
{
  DIO_SETOUT;
  CLK_SETOUT;
  DIO_HI;
  CLK_HI;
}

void TM_Start()
{
  TM_PortInit();
  DEL_US;
  DIO_LO;
  DEL_US;
}

void TM_Stop()
{
  CLK_LO;
  DEL_US;
  CLK_HI;
  DIO_LO;
  DEL_US;
  DIO_HI;
}

void TM_Send(uint8_t b)
{
	uint8_t i;
  // Clock data bits
  for ( i = 8; i; --i, b >>= 1)
  {
    CLK_LO;
    if (b & 1)
      DIO_HI;
    else
      DIO_LO;
    DEL_US;

    CLK_HI;
    DEL_US;
  }

  // Clock out ACK bit
  CLK_LO;
  DIO_LO;
  DEL_US;

  CLK_HI;
  DEL_US;
}

void TM_SendCMD(uint8_t cmd)
{
  TM_Start();
  TM_Send(cmd);
  TM_Stop();
}

void TM_SendData(const uint8_t addr, const uint8_t dat)
{
  TM_SendCMD(TM_DATA_CMD | TM_FIXED_ADDR);

  TM_Start();
  TM_Send(TM_ADDR_CMD | addr);
  TM_Send(dat);
  TM_Stop();

  DEL_US;
}

void TM_SetBrightness(const uint8_t brightness)
{
  TM_SendCMD(TM_DISP_CTRL | TM_DISP_ENABLE | (brightness & TM_DISP_PWM_MASK));
}

void TM_Clear()
{
	uint8_t a;
  for (a = 0; a != TM1637_DIGITS; ++a)
    TM_SendData(a, 0x00);
}

void TM_Init()
{
  TM_PortInit();
  TM_SendCMD(TM_DATA_CMD | TM_WRITE_DISP);
  TM_SendCMD(TM_DISP_CTRL | TM_DISP_ENABLE | TM_DISP_PWM_MASK);

  TM_Clear();
}



void TM_WritePos(const uint8_t addr, const uint8_t dat, bool dot)
{
	if(dat<36)
		TM_SendData(addr,TM_DIGITS[dat] | ((uint8_t)dot<<7));
	else if (dat>64 && dat<91)
		TM_SendData(addr,TM_DIGITS[dat-55] | ((uint8_t)dot<<7));
	else if (dat>96 && dat<123)
		TM_SendData(addr,TM_DIGITS[dat-87] | ((uint8_t)dot<<7));
}

void TM_Write(uint16_t dat)
{
	TM_SendCMD(TM_DATA_CMD);

  TM_Start();
  TM_Send(TM_ADDR_CMD);
  TM_Send(TM_DIGITS[dat/1000]);
	TM_Send(TM_DIGITS[(dat%1000)/100]);
	TM_Send(TM_DIGITS[(dat%100)/10]);
	TM_Send(TM_DIGITS[dat%10]);
  TM_Stop();

  DEL_US;
}

void TM_WriteSTR(char const* str)
{
	uint8_t i=0;
	
	while(str[i] != '\0')
	{
		TM_WritePos(i,str[i],false);
		i++;
	}
}

#ifndef __TTM1637_H__
#define __TTM1637_H__


// Enter MCU specific header files here: make sure they are "include guard"ed
#include <avr/io.h>
#include <util/delay.h>
//=================================//
// END OF MCU specific header inclusion
//=================================//

// Define the instruction which makes the pin output (e.g. DDRA |= (1<<5))
// DON'T ADD ";" in the end.
// CLK Corresponds to TM1637 clock and DIO corresponds to TM1637 DATA pin
#define CLK_SETOUT   	DDRB |= (1<<PORTB0)
#define DIO_SETOUT   	DDRB |= (1<<PORTB1)

// Define the instruction which makes the pins High or Low (e.g. PORTA |= (1<<5))
#define CLK_HI				PORTB |= (1<<PORTB0)
#define CLK_LO				PORTB &= ~(1<<PORTB0)
#define DIO_HI				PORTB |= (1<<PORTB1)
#define DIO_LO				PORTB &= ~(1<<PORTB1)
// Define a few microseconds delay. (e.g. _delay_ms(1))
#define DEL_US				//_delay_us(1)
// Define an Special directive to store data on flash 
#define FLASH_DIR	
// Define the connected 7segments displays
#define TM1637_DIGITS   4
//=================================//
// END OF USER DEFINITIONS
//=================================//



// initialize pins and other stuff
void TM_Init();
// set brightness from 0 to 7
void TM_SetBrightness(const uint8_t brightness);
// writes at the position in 7seg. from 0 to TM1637_DIGITS-1
// also, you can write any character like 'A' or 'a' but not symbols like '+'
void TM_WritePos(const uint8_t addr, const uint8_t dat, bool dot);
void TM_SendData(const uint8_t addr, const uint8_t dat);
// writes a number on screen. TM_Write(1942);
void TM_Write(uint16_t dat);
// writes an string on screen.TM_WriteSTR("Err");
void TM_WriteSTR(char const* str);
// obviously clears the display
void TM_Clear();


#endif