pressure

"You still haven't said what unit of pressure you're using - bar? atmosphere? mm of water? mm of mercury? Pascal?"

sir iam using Bar

"You still haven't said what unit of pressure you're using - bar? atmosphere? mm of water? mm of mercury? Pascal?"

sir iam using Bar

If you work in units of mV and uBar, there is no need for fractions:

Voltage Pressure
   0mV =110 000 uBar
  10mV =120 000 uBar
  20mV =130 000 uBar
   :
1000mV = 21 000 uBar
   :
2000mV =  3 100 uBar
   :
3000mV =    410 uBar
   :
4000mV =     51 uBar
   :
5000mV =      6 uBar

hellow sir

sir iam very very happy with your replys

sir here this data iam taken from a standard table

here my job is simply display the preesure for caresponing input voltage

here units are not impartent.

just i want display the pressure on display like

0.00v =1.1E-1
0.01v =1.2E-1
0.02v =1.3E-1
.
.
1.00 =2.1E-2
.
.
2.00 =3.1E-3
.
.
3.00 =4.1E-4
4.00 =5.1E-4
5.00 =6.1E-5

thank you

regards

chandu

"my job is simply display the preesure for caresponing input voltage"

If it's purely for display purposes. maybe strings would be best:

unsigned int voltage; // In units of 10mV

char pressure_string[] =
{
   "1.1E-1",   // Index 0 corresponds to  0mv
   "1.2E-1",   // Index 1 corresponds to 10mv
   "1.3E-1",   // Index 2 corresponds to 20mv
   :
   :
}

printf( "Voltage %u mV = Pressuse %s", voltage*10, pressure_string[voltage] );

thank you sir

i tried this program but iam getting one error

#include<stdio.h>
#include<reg51.h>
#include <string.h>

void main()
{
unsigned int voltage;
char pressure_string[2] ={"1.1E-1","1.2E-1","1.3E-1"};

voltage=0x0A; /*10mv*/

SCON = 0x50;
TMOD |= 0x20;
TH1 = 221;
TR1 = 1;
TI = 1;

printf( "Voltage %u mV = Pressuse %s", voltage*10, pressure_string[voltage] );
}

iam getting this error

compiling forum.c...
MAIN\FORUM.C(8): error C243: 'array[]': string out of bounds
main\forum.c - 1 Error(s), 0 Warning(s).

sir how much memory well take for 500 values of the look up table

regards

chandu

thank you sir

i tried this program but iam getting one error

#include<stdio.h>
#include<reg51.h>
#include <string.h>

void main()
{
unsigned int voltage;
char pressure_string[2] ={"1.1E-1","1.2E-1","1.3E-1"};

voltage=0x0A; /*10mv*/

SCON = 0x50;
TMOD |= 0x20;
TH1 = 221;
TR1 = 1;
TI = 1;

printf( "Voltage %u mV = Pressuse %s", voltage*10, pressure_string[voltage] );
}

iam getting this error

compiling forum.c...
MAIN\FORUM.C(8): error C243: 'array[]': string out of bounds
main\forum.c - 1 Error(s), 0 Warning(s).

sir how much memory well take for 500 values of the look up table

regards

chandu

sir

char pressure_string[] ={"1.1E-1","1.2E-1","1.3E-1"};

"compiling forum.c...
MAIN\FORUM.C(8): error C243: 'array[]': string out of bounds"

Look-up the error in the Manual - it tells you exactly what is wrong!

http://www.keil.com/support/man/docs/c51/c51_c243.htm

"how much memory well take for 500 values of the look up table"

Keil C51 does not add any extra space for padding or alignment; therefore the size of an array is simply the size of one element multiplied by the number of elements in the array.

The sizes of the data types used by C51 are listed in the Manual:

http://www.keil.com/support/man/docs/c51/c51_ap_datastorage.htm

You need to become familiar with the Manual - that doesn't mean you have to learn it by heart, but you need to be familiar with what's in it, and how to find stuff in it...

You probably also need a good 'C' textbook...

sir

i tried this expressions

char pressure_string[] ={"1.1E-1","1.2E-1","1.3E-1"};
it is showing same error



char pressure_string[3] ={"1.1E-1","1.2E-1","1.3E-1"};
it is also showing same error

then which is correct.

thank you

Oops - I made a mistake in the code I posted:

char pressure_string[] =
{
   "1.1E-1",   // Index 0 corresponds to  0mv
   "1.2E-1",   // Index 1 corresponds to 10mv
   "1.3E-1",   // Index 2 corresponds to 20mv
   :
   :
}

Iam sorry sir

i can not spot your mistake

please give solution for that one

thank you sir

It's a classic 'C' programmer's mistake!

You need to learn to spot these things if you want to do 'C' programming!
(it's the kind of thing you'd get in a 'C' test at a job interview!)

Another hint: what's the difference between a char and a string in 'C'?

Don't be afraid to look in your 'C' textbook...
(they probably won't let you do that in an interview, though!)

Have you given up?

Try

char * pressure_string[] =

hi sir
thank you
sir i tried this program

{
unsigned int voltage;
unsigned char *pressure_string[] ={"11E-1","12E-2","13E-3"};
printf( "Voltage %u mV = Pressuse %s", voltage*10, pressure_string[voltage] );
}

it is showing folling out put

"voltage 10mv=pressure 13E- "
it is not showing full value.

regards nari

When you posted your data as

0.00v =1.1E-1
0.01v =1.2E-1
0.02v =1.3E-1
.
.
1.00 =2.1E-2
.
.
2.00 =3.1E-3
.
.
3.00 =4.1E-4
4.00 =5.1E-4
5.00 =6.1E-5

char * pressure_string[] =
{
   "1.1E-1",   // Index 0 corresponds to  0mv
   "1.2E-1",   // Index 1 corresponds to 10mv
   "1.3E-1",   // Index 2 corresponds to 20mv
   :
   :
}

{
   unsigned int voltage;
   unsigned char *pressure_string[] ={ "11E-1", "12E-2", "13E-3" };

   printf( "Voltage %u mV = Pressuse %s", voltage*10, pressure_string[voltage] );
}

printf( "Voltage %u mV = Pressuse %s\r\n", voltage*10, pressure_string[voltage] );