Arduino Decibel Meter with 7-Segment Display

#include <stdio.h>
#include <string.h>
#include <Wire.h>
#include "LedControl.h"

/*
pin 12 is connected to the DataIn 
pin 11 is connected to the CLK 
pin 10 is connected to LOAD 
*/
LedControl lc=LedControl(12,10,11,1);

// I2C address for the module
#define DBM_ADDR                0x48

// Device registers
#define   DBM_REG_VERSION       0x00
#define   DBM_REG_ID3           0x01
#define   DBM_REG_ID2           0x02
#define   DBM_REG_ID1           0x03
#define   DBM_REG_ID0           0x04
#define   DBM_REG_SCRATCH       0x05
#define   DBM_REG_CONTROL       0x06
#define   DBM_REG_TAVG_HIGH     0x07
#define   DBM_REG_TAVG_LOW      0x08
#define   DBM_REG_RESET         0x09
#define   DBM_REG_DECIBEL       0x0A
#define   DBM_REG_MIN           0x0B
#define   DBM_REG_MAX           0x0C
#define   DBM_REG_THR_MIN       0x0D
#define   DBM_REG_THR_MAX       0x0E
#define   DBM_REG_HISTORY_0     0x14
#define   DBM_REG_HISTORY_99    0x77

TwoWire dbmeter;
// Buffer for printing decibel values over UART
char buf[64];

// Function to read a register from decibel meter module
uint8_t dbmeter_readreg (TwoWire *dev, uint8_t regaddr)
{
  dev->beginTransmission (DBM_ADDR);
  dev->write (regaddr);
  dev->endTransmission();
  dev->requestFrom (DBM_ADDR, 1);
  delay (10);
  return dev->read();
}

// Function to write a register to decibel meter module
uint8_t dbmeter_writereg (TwoWire *dev, uint8_t regaddr, uint8_t regdata)
{
  dev->beginTransmission (DBM_ADDR);
  dev->write (regaddr);
  dev->write (regdata);
  dev->endTransmission();
  delay (10);
  return dbmeter_readreg (dev, regaddr);
}

void setup() {
  Serial.begin (115200);
  Serial.println ("Decibel Meter test sketch");
  Serial.println ("=========================");

  // Enable 7-segment display
  lc.shutdown(0,false);
  // Set brightness to 10 (range is 0-15)
  lc.setIntensity(0,10);
  // Clear the display
  lc.clearDisplay(0);
}

void loop() {
  // Initialize I2C at 10kHz
  dbmeter.begin (10000);

  // Read version register
  uint8_t version = dbmeter_readreg (&dbmeter, DBM_REG_VERSION);
  sprintf (buf, "Version = 0x%02X\r\n", version);
  Serial.println (buf);

  // Read ID registers
  uint8_t id[4];
  id[0] = dbmeter_readreg (&dbmeter, DBM_REG_ID3);
  id[1] = dbmeter_readreg (&dbmeter, DBM_REG_ID2);
  id[2] = dbmeter_readreg (&dbmeter, DBM_REG_ID1);
  id[3] = dbmeter_readreg (&dbmeter, DBM_REG_ID0);
  sprintf (buf, "Unique ID = %02X %02X %02X %02X",
            id[3], id[2], id[1], id[0]);
  Serial.println (buf);

  // Clear the MIN and MAX reading
  dbmeter_writereg (&dbmeter, DBM_REG_RESET, 0x02);

  // Variables to store current, min and max readings
  uint8_t db, dbmin, dbmax;
  
  while (1)
  {
    // Read decibel, min and max
    db = dbmeter_readreg (&dbmeter, DBM_REG_DECIBEL);
    if (db == 255)
      continue;   // module is not ready

    dbmin = dbmeter_readreg (&dbmeter, DBM_REG_MIN);
    dbmax = dbmeter_readreg (&dbmeter, DBM_REG_MAX);

    // Generate string and print values to terminal
    sprintf (buf, ">>> Current Level: %03d dB SPL\t", db);
    sprintf (buf, "%s [MIN: %03d dB\tMAX: %03d dB]", buf, dbmin, dbmax);
    Serial.println (buf);

    // Display decibel level on 7-segment display
    lc.clearDisplay(0);
    lc.setDigit(0, 6, db/100, false);
    lc.setDigit(0, 5, (db%100)/10, false);
    lc.setDigit(0, 4, (db%10), false);
    lc.setChar(0, 2, 'd', false);
    lc.setChar(0, 1, 'B', false);
    lc.setChar(0, 0, 'A', false);
    
    // Wait for 1 second before posting another reading
    delay (1000);
  }
}