Do you have a question on Embedded electronics and controls? Ask our Expert, Paul Clarke

Also,

Anyone get the RTOS Viewer plug-in to work in MPLABX 1.00

@ asokan ambali

For instructions on creating a HEX file in Keil ARM uVision  please look at the infocenter topic CREATING INTEL HEX FILES (Applies to: uVision IDE)

HI.

Sir I want to design 12V/4A regulated power supply operated on battery supply which veries from 11,1V to 14.4V Please help me

Ajit,

You Could just use Newark Part Number: 76R0066.   SYNQOR - IQ32120QTC07NRS-GIQ32120QTC07NRS-G - DC-DC CONVERTER, 12V, 36W.   http://www.newark.com/synqor/iq32120qtc07nrs-g/dc-dc-converter-12v-36w/dp/76R0066

If you want to do it from scratch  take a look at http://www.intersil.com/data/fn/fn4324.pdf

Buck and Synchronous-Rectifier Pulse-Width Modulator (PWM) Controller 

http://en.wikipedia.org/wiki/Buck_converter

http://en.wikipedia.org/wiki/Buck-boost_converter

http://en.wikipedia.org/wiki/Flyback_converter

Paul

I have just bought Farnell part 2075388 SBC8018: TI AM1808XX with 4.3" LCD.

When I power it     the following apears on the LCD:

Please wait: booting

ANGSTROM

The Angstrom Distribution sbc8018 tty1

http://www.tim11.com 2011.09 sbc8018 tty1

sbc8018 login:

Well I didn't expect that; tim11.com is a football/sports website and I see nothing in the manual about login....

Has some one else had this device?

David

I need to send 10-bit data from the Analog to digital converter(ADC) from a dsPIC at 2Mbps through UART interface, to a bluetooth module. Then the bluetooth module should read this data through its UART

Best Regards.

i am working on atmega8 microcontroller ....

made an autonomous bot with a pair of IR sensor..!!

it can be programmed to move on white line and black line separately.. but theres a track that contains both white line and black line simultaneously...

can u give me an algorithm... so that it moves simultaneously on both black and white.. line..

the software im using is avr studio..~!

reply ASAP

sir cud u plzz tell me how to interface gsm modem with pc

specify the codes in visual basic pllzzzz i need it in urgent i knw ur the ryt person to hel me out

Hello Mr. Clarke

Im working on a simple project...and the name of my project is ELECTRONIC CODE LOCK SECURITY SYSTEM.

my problem is that i have written the source code for this project to burn it in my microcontroller.....but i have to add some additional features to it.......when i turn on the power supply...i have to enter the password and again confirm the password.......then my microcontroller asks for the typed password...if i fail to enter the correct password three times, it shows PASSWORD WRONG NO MORE TRIALS LEFT....but if i enter the correct password it shows LOCK OPEN....now i have to make it more interesting....i have to add password change option in my source code...so can u help me out on this...???

My source code is as follows :

//Program to make a code lock with user defined password

#include<reg51.h>

#define port P1

#define dataport P2

#define key P0

#define sec 100

sbit rs = port^0;

sbit rw = port^1;

sbit en = port^2;

sbit col1=key^4;

sbit col2=key^5;

sbit col3=key^6;

sbit row1=key^0;

sbit row2=key^1;

sbit row3=key^2;

sbit row4=key^3;

sbit lock_output=P0^7;

int check=0;

int digit[4]={0,0,0,0};

int dig_input[4]={0,0,0,0};

int dig_input_recheck[4]={0,0,0,0};

int i,k;

void delay(unsigned int msec) // Time delay function

{

int i,j ;

for(i=0;i<msec;i++)

  for(j=0;j<1275;j++);

}

void lcd_cmd(unsigned char item) // Function to send command to LCD

{

dataport = item;

rs= 0;

rw=0;

en=1;

delay(1);

en=0;

return;

}

void lcd_data(unsigned char item) // Function to send data to LCD

{

dataport = item;

rs= 1;

rw=0;

en=1;

delay(1);

en=0;

return;

}

void lcd_data_string(unsigned char *str) // Function to send data to string

{

int i=0;

while(str[i]!='\0')

{

  lcd_data(str[i]);

  i++;

  //delay(10);

}

return;

}

void lcd(unsigned char str[10])

{

lcd_cmd(0x38);

lcd_cmd(0x0e);

lcd_data_string(str);

}

void ans()

{

if(check>3)

{

  lcd_cmd(0x01);

  lcd_cmd(0x82);

  lcd_data_string(" LOCK OPEN");

  lock_output=1;

  delay(300);

  while(1);

  }

else

{

  lcd_cmd(0x01);

  lcd_cmd(0x82);

  lcd_data_string(" WRONG PASSWORD");

  lock_output=0;

  delay(300);

}                  

}

void code_check() // Function to check password

{

if(i<=3 )

{

  switch((i+1))

  {

   case 1: {

      if(dig_input[0]==digit[0])

      {

       check=check+1;

      }

      break;

     }

   case 2: {

      if(dig_input[1]==digit[1])

      {

       check=check+1;

      }

      break;

     }

   case 3: {

      if(dig_input[2]==digit[2])

      {

       check=check+1;

      }

      break;

     }

   case 4: {

      if(dig_input[3]==digit[3])

      {

       check=check+1;

      }

      break;

     }

  }

}

delay(10);

if(i==3)

{

  ans();

}

}

void display(int a) //Display function

{

switch(a)

{

  case 1:{

    lcd_data('*');

    delay(100);

    digit[i]=1;

    code_check();

    break;

    }

  case 2:{

    lcd_data('*');

    delay(100);

    digit[i]=2;

    code_check();

    break;

    }

  case 3:{

    lcd_data('*');

    delay(100);

    digit[i]=3;

    code_check();

    break;

    }

  case 4:{

    lcd_data('*');

    delay(100);

    digit[i]=4;

    code_check();

    break;

    }

  case 5:{

    lcd_data('*');

    delay(100);

    digit[i]=5;

    code_check();

    break;

    }

  case 6:{

    lcd_data('*');

    delay(100);

    digit[i]=6;

    code_check();

    break;

    }

  case 7:{

    lcd_data('*');

    delay(100);

    digit[i]=7;

    code_check();

    break;

    }

  case 8:{

    lcd_data('*');

    delay(100);

    digit[i]=8;

    code_check();

    break;

    }

  case 9:{

    lcd_data('*');

    delay(100);

    digit[i]=9;

    code_check();

    break;

    }

  case 0:{

    lcd_data('*');

    delay(100);

    digit[i]=0;

    code_check();

    break;

    }

}

}

void check_col1()

{

row1=row2=row3=row4=1;

row1=0;

if(col1==0)

display(1);

row1=1;

row2=0;

if(col1==0)

display(4);

row2=1;

row3=0;

if(col1==0)

display(7);

row3=1;

row4=0;

if(col1==0)

{

  row4=1;

}

}

void check_col2()

{

row1=row2=row3=row4=1;

row1=0;

if(col2==0)

display(2);

row1=1;

row2=0;

if(col2==0)

display(5);

row2=1;

row3=0;

if(col2==0)

display(8);

row3=1;

row4=0;

if(col2==0)

display(0);

row4=1;

}

void check_col3()

{

row1=row2=row3=row4=1;

row1=0;

if(col3==0)

display(3);

row1=1;

row2=0;

if(col3==0)

display(6);

row2=1;

row3=0;

if(col3==0)

display(9);

row3=1;

row4=0;

if(col3==0)

{

  row4=1;

}

}

void check_password_col1()

{

row1=row2=row3=row4=1;

row1=0;

if(col1==0)

dig_input[k]=1;

row1=1;

row2=0;

if(col1==0)

dig_input[k]=4;

row2=1;

row3=0;

if(col1==0)

dig_input[k]=7;

row3=1;

row4=0;

if(col1==0)

{

  row4=1;

}

}

void check_password_col2()

{

row1=row2=row3=row4=1;

row1=0;

if(col2==0)

dig_input[k]=2;

row1=1;

row2=0;

if(col2==0)

dig_input[k]=5;

row2=1;

row3=0;

if(col2==0)

dig_input[k]=8;

row3=1;

row4=0;

if(col2==0)

{

  dig_input[k]=0;

  row4=1;

}

}

void check_password_col3()

{

row1=row2=row3=row4=1;

row1=0;

if(col3==0)

dig_input[k]=3;

row1=1;

row2=0;

if(col3==0)

dig_input[k]=6;

row2=1;

row3=0;

if(col3==0)

dig_input[k]=9;

row3=1;

row4=0;

if(col3==0)

{

  row4=1;

}

}

void pass_set()

{

row1=row2=row3=row4=0;

while(col1==1 && col2==1 && col3==1);

for(i=0;i<4;i++)

{

  k=i;

  delay(50);

  lcd_cmd(0xc4+i);

  delay(100);

  row1=row2=row3=row4=0;

  while(col1==1 && col2==1 && col3==1);

  row1=row2=row3=row4=0;

  if(col1==0)

  check_password_col1();

  else

   if(col2==0)

   check_password_col2();

   else

    if(col3==0)

    check_password_col3();

  lcd_data('*');

  delay(50);

}

}

void main()

{

int e,j=0,count=1;

col1=col2=col3=1;

//FOR PASSWoRD INPUT

do

{

  lcd_cmd(0x01);  //Clear LCD screen

  lcd_cmd(0x81); 

  lcd("ENTER PASSWORD:");

  pass_set();

  for(e=0;e<4;e++)

  dig_input_recheck[e]=dig_input[e];

  lcd_cmd(0x01);

  lcd("CONFIRM PASSWORD:");

  pass_set();

  for(e=0;e<4;e++)

  {

   if(dig_input_recheck[e]==dig_input[e])

   j++;

  }

  if(j<4)

  {

   lcd_cmd(0x01);

   lcd_cmd(0x85);

   lcd("PASSWORD");

   lcd_cmd(0xC2);

   lcd("NOT MATCH");

   delay(300);

  }

}

while(j<4);

while(count<4)          //Code input and check

{

  lcd_cmd(0x01);

  lock_output=0;

  lcd_cmd(0x82); 

  lcd("ENTER PASSWORD");

  check=0;

  row1=row2=row3=row4=0;

  while(col1==1 && col2==1 && col3==1);

  for(i=0;i<4;i++)

  {

   delay(100);

   lcd_cmd(0xc4+i);

   row1=row2=row3=row4=0;

   while(col1==1 && col2==1 && col3==1);

   row1=row2=row3=row4=0;

   if(col1==0)

   check_col1();

   else

    if(col2==0)

    check_col2();

    else

     if(col3==0)

     check_col3();

  }

  count++;

  delay(1);  

}

if(count==4)

{

  lcd_cmd(0x01);

  lcd_cmd(0x86);

  lcd("SORRY");

  lcd_cmd(0xc1);

  lcd("NO MORE TRIALS");

  while(1);

}

}

hello sir

          I want to design waveform such that for one period it will be a sine wave and even negative cycle has to be clipped. so help me in this regard how to design this circuit