Thread: Help on C Function

Hi Guys! I am new to C Programming and I currently tasked to write a function that can "decode" the following quad site protocol received. However I am stuck as to how to continue with the function. Here is the protocol.

€€Ïrs 1,1,1,10
€€Ïrs 10,1,1,10
€€Ïrs 1,1,1,10
€€Ïrs 1,1,1,1
€€Ïrs 10,1,10,7
€€Ïrs 1,1,7,10
€€Ïrs 1,1,10,1
€€Ïrs 10,1,10,10
€€Ïrs 1,10,10,1
€€Ïrs 1,10,7,1
€€Ïrs 1,1,1,5
€€Ïrs 1,1,1,1
€€Ïrs 1,1,1,1
€€Ïrs 1,1,1,7
€€Ïrs 1,1,1,5
€€Ïrs 1,1,1,1
€€Ïrs 1,10,1,1
€€Ïrs 1,1,1,1
€€Ïrs 1,1,1,5
€€Ïrs 1,1,1,1
€€Ïrs 1,1,1,5
€€Ïrs 6,1,7,1
€€Ïrs 6,1,1,1
€€Ïrs 1,1,1,1
€€Ïrs 1,7,1,1
€€Ïrs 6,1,1,1
€€Ïrs 1,1,1,5
€€Ïrs 1,1,1,1
€€Ïrs 1,1,10,5
€€Ïrs 1,10,1,10
€€Ïrs 1,10,1,10
��ßrs 10,10,1,10
��ßrs 1,10,1,10
€€Ïrs 1,1,1,1
€€Ïrs 1,1,10,5
€€Ïrs 1,1,1,10

Currently my function can only support receiving dual site protocols. Like the following:

rs 1,,,1
rs 10,,,1
rs 1,,,10
rs 1,,,1
rs 1,,,1
rs 1,,,7
rs 1,,,1
rs 1,,,7

Attached is my c code. I have tried using case to handle the extra quad site protocols but it seems like it is unable to support. I complie my code using SDCC. Attached are my original code for the dual site and code for the quad site. I would appreciate if someone could help me out on this. Thanks alot!

I took one look at your quad site code, and I can tell you that most of the code is unnecessary due to extreme repetition and many ways to optimize it, using, for example, some simple arithmetic.

Originally Posted by Salem

How about writing a small test program which specifically focusses on the problem at hand.

Not the 75K of source containing all sorts of irrelevance.

I would love to but I can't. I have been thrown this pile of code to look at and I don't even know where to begin coz I am not trained in C!

I think the problem lies with this line of code:

Code:

if(c=='r') //J750
{
command_detected=1;
i=0;
}

because for dual site protocols, the signal transmitted is rs 10,,,1
but for quad site protocols, the signal transmitted is €€Ïrs 10,1,10,10
and the quad site protocol begins with this funny character €. I believe this funny character prevents the from executing, therefore it is unable to go inside into the if statements which are nested in it.

Actually the rest of the codes are all relevant. They are used to communicate with a 8051 microcontroller. =)

Originally Posted by IceDane

I took one look at your quad site code, and I can tell you that most of the code is unnecessary due to extreme repetition and many ways to optimize it, using, for example, some simple arithmetic.

Maybe they could have been simpler but I have no idea as they are thrown at me so I am trying my best to understand but due to my limited knowledge, I have decided to seek help in this forum.
I believe not all of the rest of the codes are redundant. Most of them are used to communicate with a 8051 Microcontroller. Thats the main purpose of this code.

Originally Posted by Salem

> and I don't even know where to begin coz I am not trained in C!
Does your boss know this?

> I believe this funny character prevents the from executing,
> therefore it is unable to go inside into the if statements which are nested in it.
That's pretty much it.
So all you need really is something like
if ( c == 0xdc )

Well you'll have to look up the actual numeric values for your "€€Ï" chars, but you get the general idea.

My boss knows my predicament. But he doesn't give a hoot about it. =( He expects me to deliver the goods.
Anyway thanks for your suggestion. I'll go look for the actual numeric values for the "€€Ï" chars.
Anyway do you know whats this "€€Ï" char stand for?