DTMF DECODER SHIELD FOR ARDUINO

INTRODUCTION

 This board decodes DTMF signal either from an audio source or phone line to 4 bit binary TTL(5V) level output. It also indicates outputs with LED. Suitable for use with microcontroller applications.

FEATURES

• Decodes DTMF as 4 bit binary
• TTL level output for direct connection to microcontrollers
• Low power 5V DC operation
• LED indication of outputs
• Simple to use.
• High quality PCB FR4 Grade with FPT Certified.

ARDUINO I/O CONNECTIONS

 

ARDUINO CODE

/*

 * Project name:

    DTMF Decoder shield 

 * Copyright

     (c) Researchdesignlab.com

 * Description:

   

 * Test configuration:

     MCU:             ATMEGA328

     Dev.Board:       Arduino uno

     Oscillator:      16 MHz

     Software:        Arduino

*/

const int analogInPin1 = A0; // Analog input pin that the potentiometer is attached to x axis Joystick
const int analogInPin2 = A1; // Analog input pin that the potentiometer is attached to y axis Joystick
const int buttonPin_A = 2; // the number of the D0 pin 
const int buttonPin_B = 3; // the number of the D1 B pin 
const int buttonPin_C = 4; // the number of the D2 C pin 
const int buttonPin_D = 5; // the number of the D3 D pin 
const int buttonPin_E = 6; // the number of the STD pin

int sensorValue = 0; // value read from the pot
int D0,D1,D2,D3,STD; // variable for reading the pushbutton status

void setup() {
// initialize serial communications at 9600 bps:
Serial.begin(9600); 
Serial.println("DTMF Decoder shield ");
Serial.println(" " ); 

// initialize the pushbutton pin as an input:
pinMode(buttonPin_A, INPUT); 
pinMode(buttonPin_B, INPUT); 
pinMode(buttonPin_C, INPUT); 
pinMode(buttonPin_D, INPUT); 
pinMode(buttonPin_E, INPUT);

}

void loop() {

// read the state of the pushbutton A,B,C,D,E value:
D0 = digitalRead(buttonPin_A); 
D1 = digitalRead(buttonPin_B); 
D2 = digitalRead(buttonPin_C); 
D3 = digitalRead(buttonPin_D); 
STD = digitalRead(buttonPin_E); 

if (STD == HIGH) { 
delay(400); 
if((D0==1)&&(D1==0)&&(D2==0)&&(D3==0))
{

Serial.print('1');
}
if((D0==0)&&(D1==1)&&(D2==0)&&(D3==0))
{

Serial.print('2');
}
if((D0==1)&&(D1==1)&&(D2==0)&&(D3==0))
{

Serial.print('3');
}
if((D0==0)&&(D1==0)&&(D2==1)&&(D3==0))
{

Serial.print('4');
}
if((D0==1)&&(D1==0)&&(D2==1)&&(D3==0))
{

Serial.print('5');
}
if((D0==0)&&(D1==1)&&(D2==1)&&(D3==0))
{

Serial.print('6');
}
if((D0==1)&&(D1==1)&&(D2==1)&&(D3==0))
{

Serial.print('7');
}
if((D0==0)&&(D1==0)&&(D2==0)&&(D3==1))
{
Serial.print('8');
}
if((D0==1)&&(D1==0)&&(D2==0)&&(D3==1))
{

Serial.print('9');
}
if((D0==0)&&(D1==1)&&(D2==0)&&(D3==1))
{

Serial.print('0');
}
if((D0==1)&&(D1==1)&&(D2==0)&&(D3==1))
{

Serial.print('*');
}
if((D0==0)&&(D1==0)&&(D2==1)&&(D3==1))
{

Serial.print('#');
}
while(STD!=LOW)
{
STD = digitalRead(buttonPin_E);
}

}

 

 

BAROMETRIC DIGITAL PRESSURE SENSOR BMP085

OVERVIEW

INTRODUCTION

This is a breakout board for the BMP085 high-precision, low-power digital barometer. The BMP085 offers a measuring range of 300 to 1100 hPa with accuracy down to 0.03 hPa in ultra-high resolution mode (that's 0.25m of altitude at sea level!) It's based on piezo-resistive technology for high accuracy, ruggedness and long term stability. These come factory-calibrated, with the calibration coefficients already stored in ROM. Writing your own code for it requires some math.

This breadboard-friendly board breaks out every pin to a 6-pin 0.1" pitch header. VCC can be from 1.8V to 3.6V; we typically run it on a clean, regulated 3.3V supply. The analog and digital supplies (VDDD and VDDA) are tied to a single header pin, but are separately decoupled. It connects to a microcontroller via I²C bus .

FEATURES

• Digital two wire (I²C, TWI, "Wire") interface
• Wide barometric pressure range
• Flexible supply voltage range (1.8V to 3.6V)
• Ultra-low power consumption
• Low noise measurements
• Factory-calibrated
• Includes temperature sensor
• Low-profile with a small footprint.

HARDWARE  EXPLANATION

'SDA', 'SCL', 'XCLR', 'EOC', 'GND,and'VCC.' VCC and GND are obviously the power pins. SDA and SCL are the I2C communication lines. SDA being where the data is transmitted and SCL is the clock that keeps track of that data. The last two pins, XCLR and EOC, are a couple extra functions of the BMP085. XCLR acts as a master reset. It's active-low, so if it's pulled to GND it will reset the BMP085 and set its registers to their default state. EOC, standing for "end of conversion", is a signal generated by the BMP085 that's triggered whenever a pressure or temperature conversion has finished.

APPLICATIONS

1. Pressure sensing
2. Altitude sensing
3. Flow sensing
4. Level / depth sensing

ARDUINO CODE

#include <Wire.h>

#define BMP085_ADDRESS 0x77   // I2C address of BMP085

const unsigned char OSS = 0;   // Oversampling Setting

// Calibration values

int ac1;

int ac2;

int ac3;

unsigned int ac4;

unsigned int ac5;

unsigned int ac6;

int b1;

int b2;

int mb;

int mc;

int md;

// b5 is calculated in bmp085GetTemperature(...), this variable is also used in bmp085GetPressure(...)

// so ...Temperature(...) must be called before ...Pressure(...).

long b5;

short temperature;

long pressure;

void setup()

{

  Serial.begin(9600);

  Wire.begin();

  bmp085Calibration();

}

void loop()

{

  temperature = bmp085GetTemperature(bmp085ReadUT());

  pressure = bmp085GetPressure(bmp085ReadUP());

  Serial.print("Temperature: ");

  Serial.print(temperature, DEC);

  Serial.println(" *0.1 deg C");

  Serial.print("Pressure: ");

  Serial.print(pressure, DEC);

  Serial.println(" Pa");

  Serial.println();

  delay(1000);

}

// Stores all of the bmp085's calibration values into global variables

// Calibration values are required to calculate temp and pressure

// This function should be called at the beginning of the program

void bmp085Calibration()

{

  ac1 = bmp085ReadInt(0xAA);

  ac2 = bmp085ReadInt(0xAC);

  ac3 = bmp085ReadInt(0xAE);

  ac4 = bmp085ReadInt(0xB0);

  ac5 = bmp085ReadInt(0xB2);

  ac6 = bmp085ReadInt(0xB4);

  b1 = bmp085ReadInt(0xB6);

  b2 = bmp085ReadInt(0xB8);

  mb = bmp085ReadInt(0xBA);

  mc = bmp085ReadInt(0xBC);

  md = bmp085ReadInt(0xBE);

}

// Calculate temperature given ut.

// Value returned will be in units of 0.1 deg C

short bmp085GetTemperature(unsigned int ut)

{

  long x1, x2;

  x1 = (((long)ut - (long)ac6)*(long)ac5) >> 15;

  x2 = ((long)mc << 11)/(x1 + md);

  b5 = x1 + x2;

 return ((b5 + 8)>>4);  

}

// Calculate pressure given up

// calibration values must be known

// b5 is also required so bmp085GetTemperature(...) must be called first.

// Value returned will be pressure in units of Pa.

long bmp085GetPressure(unsigned long up)

{

  long x1, x2, x3, b3, b6, p;

  unsigned long b4, b7;

 b6 = b5 - 4000;

  // Calculate B3

  x1 = (b2 * (b6 * b6)>>12)>>11;

  x2 = (ac2 * b6)>>11;

  x3 = x1 + x2;

  b3 = (((((long)ac1)*4 + x3)<<OSS) + 2)>>2;

 // Calculate B4

  x1 = (ac3 * b6)>>13;

  x2 = (b1 * ((b6 * b6)>>12))>>16;

  x3 = ((x1 + x2) + 2)>>2;

  b4 = (ac4 * (unsigned long)(x3 + 32768))>>15;

  b7 = ((unsigned long)(up - b3) * (50000>>OSS));

  if (b7 < 0x80000000)

    p = (b7<<1)/b4;

  else
    p = (b7/b4)<<1;
  x1 = (p>>8) * (p>>8);
  x1 = (x1 * 3038)>>16;
  x2 = (-7357 * p)>>16;
  p += (x1 + x2 + 3791)>>4;

  return p;
}
// Read 1 byte from the BMP085 at 'address'
char bmp085Read(unsigned char address)
{
  unsigned char data;
  Wire.beginTransmission(BMP085_ADDRESS);
  Wire.write(address);
  Wire.endTransmission();
 Wire.requestFrom(BMP085_ADDRESS, 1);
  while(!Wire.available());
    return Wire.read();
}
// Read 2 bytes from the BMP085
// First byte will be from 'address'
// Second byte will be from 'address'+1

int bmp085ReadInt(unsigned char address)

{

  unsigned char msb, lsb;

  Wire.beginTransmission(BMP085_ADDRESS);

  Wire.write(address);

  Wire.endTransmission();

  Wire.requestFrom(BMP085_ADDRESS, 2);

  while(Wire.available()<2)

    ;

  msb = Wire.read();

  lsb = Wire.read();

  return (int) msb<<8 | lsb;

}

// Read the uncompensated temperature value

unsigned int bmp085ReadUT()

{

  unsigned int ut;

 // Write 0x2E into Register 0xF4

  // This requests a temperature reading

  Wire.beginTransmission(BMP085_ADDRESS);

  Wire.write(0xF4);

  Wire.write(0x2E);

Wire.endTransmission();

  // Wait at least 4.5ms

  delay(5);

 // Read two bytes from registers 0xF6 and 0xF7

  ut = bmp085ReadInt(0xF6);

  return ut;

}

// Read the uncompensated pressure value

unsigned long bmp085ReadUP()

{

  unsigned char msb, lsb, xlsb;

  unsigned long up = 0;

  // Write 0x34+(OSS<<6) into register 0xF4

  // Request a pressure reading w/ oversampling setting

  Wire.beginTransmission(BMP085_ADDRESS);

  Wire.write(0xF4);

  Wire.write(0x34 + (OSS<<6));

  Wire.endTransmission();

  // Wait for conversion, delay time dependent on OSS

  delay(2 + (3<<OSS));

// Read register 0xF6 (MSB), 0xF7 (LSB), and 0xF8 (XLSB)

  Wire.beginTransmission(BMP085_ADDRESS);

  Wire.write(0xF6);

  Wire.endTransmission();

  Wire.requestFrom(BMP085_ADDRESS, 3);

  // Wait for data to become available

  while(Wire.available() < 3) ;

  msb = Wire.read();

  lsb = Wire.read();

  xlsb = Wire.read();

 up = (((unsigned long) msb << 16) | ((unsigned long) lsb << 8) | (unsigned long) xlsb) >> (8-OSS);

 return up;

}

OUTPUT

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