Solved

Getting bytes from a memory that's dymanicly allocated.

Posted on 1997-07-18
11
174 Views
Last Modified: 2010-04-06
Hi!
Here is what I'm working with:
Buffpointer: Pointer;

GetMem( BuffPointer, 2048 );
ReadFile(hComm, BuffPointer^, 10, NbrRead, @overlappedRead)

The ReadFile is reading from the serial communications-port with a baudrate at 115200, and I know that the other computer is sending bytes containing information from an A/D-converter. Therefore I want to get the value on every byte(0 - 255) so I then can use it to draw a curve on the screen.

 If I do PChar(BuffPointer) the result is in Char and the information that I want is lost. Maybe You have another idea on how I should do?
Thanks!

Regards Linda.
0
Comment
Question by:Lillan061397
  • 7
  • 4
11 Comments
 

Author Comment

by:Lillan061397
ID: 1339137
Edited text of question
0
 

Author Comment

by:Lillan061397
ID: 1339138
Edited text of question
0
 
LVL 2

Expert Comment

by:icampbe1
ID: 1339139
Hi Linda,

Maybe if you tell more about your task.  Are you trying to read the file to get character pairs and then use these pairs to create a Unicode (Like Swedish) string ??

 Also, when you say holes in the ASCII chart, I assume you mean the values above 127.

Ian C.
0
 
LVL 2

Expert Comment

by:icampbe1
ID: 1339140
Most of the conversion routines (at least in D3) do this internally already.
0
 

Author Comment

by:Lillan061397
ID: 1339141
Edited text of question
0
Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

 

Author Comment

by:Lillan061397
ID: 1339142
Edited text of question
0
 
LVL 2

Accepted Solution

by:
icampbe1 earned 50 total points
ID: 1339143
Use a typed pointer.

VAR
    BuffPointer: ^BYTE;

Type BYTE is just 8 bits of binary storage.  It does not have a Char personality.  Also, make sure to set up the Com port for binary transfers.

Ian C.

0
 

Author Comment

by:Lillan061397
ID: 1339144
Hi Ian!

I hope the editing of the question is better. If a bytes value is 97 I want to be able to get 97 as an integer and not an 'a'. I'm using this to draw a curve. Is this possible? I hope so!!

Regards Linda.
0
 
LVL 2

Expert Comment

by:icampbe1
ID: 1339145
Yes, use BYTE not CHAR.  A type of BYTE doesn't know about 'a' or 'b'.  It just is 8 binary bits of storage.  If you want it as a signed integer, use SHORTINT.

BYTE and SHORTINT are the 8 bit equivalents of WORD and INTEGER.

Does this help?

Ian C.
0
 

Author Comment

by:Lillan061397
ID: 1339146
Hi again!

I can only get the first byte! How do I do to get the second and so on? Otherwise it's working.

Regards
Linda.
0
 

Author Comment

by:Lillan061397
ID: 1339147
Hi Ian!

After about 10 sec I figured out how to read all the bytes!

Thanks for your help!

Linda.
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
automatically logging in via bde delphi 3 68
QRReport  TQrmemo vertical stretching 1 42
select query - oracle 16 91
SUM 2 INTEGER ARRAYS INTO 1 10 93
Objective: - This article will help user in how to convert their numeric value become words. How to use 1. You can copy this code in your Unit as function 2. than you can perform your function by type this code The Code   (CODE) The Im…
Have you ever had your Delphi form/application just hanging while waiting for data to load? This is the article to read if you want to learn some things about adding threads for data loading in the background. First, I'll setup a general applica…
A short film showing how OnPage and Connectwise integration works.
This is a video describing the growing solar energy use in Utah. This is a topic that greatly interests me and so I decided to produce a video about it.

919 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

21 Experts available now in Live!

Get 1:1 Help Now