[SOLVED] i have an error when i want to convert unsigned char to long int in codevision

• Jan 16, 2011

• #1

M

mahm150

Full Member level 1

Joined

Dec 14, 2010

Messages

98

Helped

1

Reputation

2

Reaction score

1

Trophy points

1,288

Location

Cairo, Egypt, Egypt

Activity points

2,001

i have an error when i want to convert unsigned char to long int or unsigned int in codevision altough i check in promote char to int .
unsigned char data;
unsigned int long_data;
unsigned int address;

address+=1;
while(x<9)
{
data=EEprom_READ(address);
long_data = (long_data << x)|data ;
x+=8;
address-=1;
}

 

• Jan 16, 2011

• #2

VSMVDD

Banned

Joined

Jun 12, 2005

Messages

643

Helped

92

Reputation

184

Reaction score

34

Trophy points

1,308

Location

scotland uk

Activity points

0

its the move left is the issue

you need to use split word then add two words together


your code measures in levels of indifference
so pad 0 then...add with shift...

 

• Jan 16, 2011

• #3

M

mahm150

Full Member level 1

Joined

Dec 14, 2010

Messages

98

Helped

1

Reputation

2

Reaction score

1

Trophy points

1,288

Location

Cairo, Egypt, Egypt

Activity points

2,001

i make that (unsigned int)data=EEprom_READ(address);
and now i test until now it work good
about VSMVDD u mean that
data1 =EEprom_READ(address-1);
long_data =(unsigned int) data1 | data ;
or what do you mean about this sentence
your code measures in levels of indifference
so pad 0 then...add with shift...

 

• Jan 16, 2011

• #4

D

Denshil

Junior Member level 2

Joined

Dec 31, 2010

Messages

23

Helped

15

Reputation

32

Reaction score

15

Trophy points

1,283

Location

Sri Lanka

Activity points

1,460

mahm150 said:

long_data =(unsigned int) data1 | data ;

Click to expand...

I think mikroC auto convert, unsigned char to unsigned long int.
Don’t want to explicitly convert like that.

unsigned char charValue;
unsigned long int output;
void main(){
charValue=50;
output=0;
output= EEPROM_Read(charValue)/charValue;

}

 

Last edited: Jan 16, 2011

• Jan 16, 2011

• #5

M

mahm150

Full Member level 1

Joined

Dec 14, 2010

Messages

98

Helped

1

Reputation

2

Reaction score

1

Trophy points

1,288

Location

Cairo, Egypt, Egypt

Activity points

2,001

i not used mikroC. i use codevison
i think that my code now work good when i make this (unsigned int)data=EEprom_READ(address);

 

• Jan 16, 2011

• #6

alexan_e

Administrator

Joined

Mar 16, 2008

Messages

11,888

Helped

2,021

Reputation

4,158

Reaction score

2,031

Trophy points

1,393

Location

Greece

Activity points

64,371

mahm150 said:

i not used mikroC. i use codevison
i think that my code now work good when i make this (unsigned int)data=EEprom_READ(address);

Click to expand...

You can use

Code:

long_data = (long_data)|((unsigned int)data<<x) ;

shift the type-casted data and then OR with your variable,take care of the correct order of your bytes because this is the reverse of what you do.

I don't understand what does the (unsigned int)data=EEprom_READ(address); do , you are reading an 8bit variable into an 8bit variable, what is the point of typecasting at this point.

Alex

 

• Jan 16, 2011

• #7

M

mahm150

Full Member level 1

Joined

Dec 14, 2010

Messages

98

Helped

1

Reputation

2

Reaction score

1

Trophy points

1,288

Location

Cairo, Egypt, Egypt

Activity points

2,001

i make that because i read two bytes as u understand then make that
long_data = (long_data << x)|data ;//x=8
the long_data is (unsigned int).

 

• Jan 16, 2011

• #8

alexan_e

Administrator

Joined

Mar 16, 2008

Messages

11,888

Helped

2,021

Reputation

4,158

Reaction score

2,031

Trophy points

1,393

Location

Greece

Activity points

64,371

Yes but when you use typecast in a part of your program (unsigned int)data=EEprom_READ(address); then it is valid only for that specific point,
this typecast is not preserved for the rest of the program so i don't understand why it makes a difference in the rest of the code.

Alex

 

• Jan 16, 2011

• #9

M

mahm150

Full Member level 1

Joined

Dec 14, 2010

Messages

98

Helped

1

Reputation

2

Reaction score

1

Trophy points

1,288

Location

Cairo, Egypt, Egypt

Activity points

2,001

i will try to comment in this casting then i wil tell u the result

---------- Post added at 19:38 ---------- Previous post was at 19:31 ----------

it work good ; that u mean i not need to make cast in long_data = (long_data << x)|data
although data unsigned char

 

• Jan 16, 2011

• #10

dani222

Banned

Joined

Jan 8, 2011

Messages

20

Helped

2

Reputation

4

Reaction score

2

Trophy points

1,283

Activity points

0

Hello dear friend
Training to an article I introduce the programming you codevision ..!!

If you say you love?

 

• Jan 16, 2011

• #11

alexan_e

Administrator

Joined

Mar 16, 2008

Messages

11,888

Helped

2,021

Reputation

4,158

Reaction score

2,031

Trophy points

1,393

Location

Greece

Activity points

64,371

mahm150 said:

i will try to comment in this casting then i wil tell u the result

---------- Post added at 19:38 ---------- Previous post was at 19:31 ----------

it work good ; that u mean i not need to make cast in long_data = (long_data << x)|data
although data unsigned char

Click to expand...

No , i said that you need to use typecast in long_data = (long_data)|((unsigned int)data<<x) ; or anyway you do it
but not in (unsigned int)data=EEprom_READ(address);

It is not wrong but there is no point to use a typecast when you write an 8bit value in a 8bit variable, EEprom_READ should returns a byte.

Alex

 

• Jan 16, 2011

• #12

M

mahm150

Full Member level 1

Joined

Dec 14, 2010

Messages

98

Helped

1

Reputation

2

Reaction score

1

Trophy points

1,288

Location

Cairo, Egypt, Egypt

Activity points

2,001

but how it work good when i comment cast

 

• Jan 16, 2011

• #13

alexan_e

Administrator

Joined

Mar 16, 2008

Messages

11,888

Helped

2,021

Reputation

4,158

Reaction score

2,031

Trophy points

1,393

Location

Greece

Activity points

64,371

Many things work without a typecast but maybe will stop working with another compiler,
to make sure that everything will be treated as you want to you have to force the compiler with typecasting.

Alex

 

• Jan 16, 2011

• #14

M

mahm150

Full Member level 1

Joined

Dec 14, 2010

Messages

98

Helped

1

Reputation

2

Reaction score

1

Trophy points

1,288

Location

Cairo, Egypt, Egypt

Activity points

2,001

i understand u now i make that
long_data = (long_data << x)|(unsigned int)data ;
but i not understand how it work good when i comment cast

 

• Jan 16, 2011

• #15

alexan_e

Administrator

Joined

Mar 16, 2008

Messages

11,888

Helped

2,021

Reputation

4,158

Reaction score

2,031

Trophy points

1,393

Location

Greece

Activity points

64,371

Which cast do you remove?
You mean long_data = (long_data << x)|data ;

This can work because you are using shift left in a variable that is 16 bit long so the 8 bits lower bits can go 8 positions to the left without a problem, then you OR with a 8bit value, it is normal to OR the lower 8bits of the integer with a 8 bit variable.
If you use shift left 8 in a 8bit variable ir will become 0 because it will still be an 8 bit variable with 8 zeros shifted in, in that case you need to typecast first as a 16bit variable and then shift.

Alex

 

• Jan 16, 2011

• #16

M

mahm150

Full Member level 1

Joined

Dec 14, 2010

Messages

98

Helped

1

Reputation

2

Reaction score

1

Trophy points

1,288

Location

Cairo, Egypt, Egypt

Activity points

2,001

its OK i understand

 

• Jan 16, 2011

• #17

alexan_e

Administrator

Joined

Mar 16, 2008

Messages

11,888

Helped

2,021

Reputation

4,158

Reaction score

2,031

Trophy points

1,393

Location

Greece

Activity points

64,371

For example
0xFF<<8 becomes 0x00
(unsigned int)0xFF<<8 becomes 0xFF00 (16 bit result)

 

• Jan 16, 2011

• #18

dani222

Banned

Joined

Jan 8, 2011

Messages

20

Helped

2

Reputation

4

Reaction score

2

Trophy points

1,283

Activity points

0

Examples and instructions Take a look this article

**broken link removed**

And password to download the form below: Be careful:

 

• Jan 17, 2011

• #19

M

mahm150

Full Member level 1

Joined

Dec 14, 2010

Messages

98

Helped

1

Reputation

2

Reaction score

1

Trophy points

1,288

Location

Cairo, Egypt, Egypt

Activity points

2,001

i download u book but its language not arabic or english cant read