16F877A problem: "coupled" digital values

[Darrel Taylor]

Hi Lupo,

Good answer. Not a problem.

I think you need some delay between selecting the A/D channel (with ADCON0) and starting the conversion (ADGO = 1;) for sample Aquisition time.

Starting it too soon won't allow the internal Sample and Hold capacitor to fully charge. Which leaves part of the charge from the last channel in it.

HTH,

[Lupo83]

Ciao Darrel,

your answer is the most useful I've read so far, so I thank you very much for that!

I'll test your solution tomorrow morning, since the board/PIC I'm working on are not mine, but have to stay in a laboratory at my university.

Then, I'll let you know.

Best regards.

[mackrackit]

Of course, I apologize if my post here was unappropriate:

I do not think your post was inappropriate, just thought you posted to the wrong forum.
There are a few here that use "C" and I understand needing help.

Tried PIC programming in "C" a few years ago and like you I could not find help. That was one of the reasons I ended up using PIC BASIC.

Good luck.

[Lupo83]

Good morning everybody (here it's 11:40 AM).

Dear Darrel, your suggestion worked fine! You've been the only one to solve the problem, congrats!! I thank you very much for your competence. Hope to get as experienced as you, first or later

[Dave]

Lupo83, If you would have read the data sheet for the PIC it would have told you that there is a minimum time required for the A/D caps to charge before taking a measurement. It's in the Data sheet......

Dave Purola,
N8NTA

[mister_e]

PICMultiCalc (A/D calc) could also be useful, it use a generic maths formula. The whole idea started with this article....
http://www.sfcompiler.co.uk/wiki/pmw...User.MinADtime

Some may recognize the author ?

[Lupo83]

Ciao Dave,

sometimes one's attention misses some information when reading a 234 pages document, after being required to produce working code, starting from nothing, in 3 days and without a PIC programming background
I found myself in a pressing situation and just needed to ask some help, since time was lacking
Thank you for the link, mister_e!

Bye,
L.

PS: Maybe the correct form for your sentence is "If you had read...."....?

[Darrel Taylor]

That's great Lupo,

It's tough being an outsider sometimes.
But I'm glad it worked out for you!

If you get a chance, come on in. The waters nice. (PBP)
and we have Lifeguards.
<br>

[T.Jackson]

I do not think your post was inappropriate, just thought you posted to the wrong forum.
There are a few here that use "C" and I understand needing help.

Tried PIC programming in "C" a few years ago and like you I could not find help. That was one of the reasons I ended up using PIC BASIC.

Good luck.

C / Java is not as intimidating as it first looks - but you will find it difficult to learn from just reading a book. I learned more about Java from 100pgs of lecture material that was straight to the point than I did from reading portions of a 1,000pg book. The practical assignments helped as well. It's clearly a language that needs to be taught formally with a lot of resources for help.

[mackrackit]

C / Java is not as intimidating as it first looks.

About six months ago I purchased two Java books. I am starting to make a little progress. Now my biggest problem is finding time to work on it. The IDEs like NetBeans just made it more confusing. Every one seems to have a different method. Now I am using gedit and compiling from the command line.

[T.Jackson]

Personally, I just compile at console level. Typically I'll have two instances, 1 for compiling and the other for running / testing. As you may or may not be aware, java files need to be launched at console level unless you create a jar file with the inclusion of a manifest in order to be able to execute the program at OS level (double click to run) - which is your typical Windows-based executable. Sadly, this is as about as good as it gets for a standalone application with Java.

[mackrackit]

I got the manifest and jar things figured out. Those were some of the things the books did not cover well. Google to the rescue.

The thing I like about java and the reason I want to learn it is its cross platform capability.