ADC Input block - solved

Post Reply
Bernard Leak
Posts: 18
Joined: Fri Aug 15, 2008 3:42 pm
Location: Armitage, Staffordshire, England

ADC Input block - solved

Post by Bernard Leak » Tue Aug 26, 2008 10:04 am

M. Kerhuel,
there is still a problem with the ADC Input block.

For dsPIC33FJ256GP710, it gives the permitted
analogue input pins as 0-21 and 24-33, instead of
0-31 (which is certainly correct)

It is as though 22 and 23 were entered as 32 and 33, and the list was
then sorted into order. Typing 22 produces a dialogue
box:

RTW for PIC 16 MCU error
Subscript indices must either be real positive indices or logicals.

Checking the nearest convenient data-sheet,
Microchip's 70286A (covering dsPIC33FJXXXGPX06/X08/X10)
whenever AN21 is present AN22 and AN23 are also present:
that is, on

dsPIC33FJ{64,128}GP708
dsPIC33FJ{64,128}GP310
dsPIC33FJ256GP510
dsPIC33FJ{64,128,256}GP710

all but the GP708 versions continue with
pins AN24 - AN31: the GP708 stops with AN23.

On the other hand, I don't actually get any input on AN22, even
when I modify AD1CSSH to set the bit I want. I don't yet
understand this, and it might be relevant if I did. It is possible
that this is a problem with the hardware (or my understanding
of it), but I thought I should mention it.

Bernard Leak

Bernard Leak
Posts: 18
Joined: Fri Aug 15, 2008 3:42 pm
Location: Armitage, Staffordshire, England

Re: ADC Input block

Post by Bernard Leak » Thu Aug 28, 2008 5:06 pm

Dear List,
I am using version 0.98fb of the dsPIC block-set,
dated 21st August 2008, for MatLab R2006b.

The list picRef.AN is wrong: it contains spurious
NaNs at indices 23 and 24 (1-based: 22 and 23 if 0-based)
which cause AN22 and AN23 to "vanish", and all
higher-numbered analogue pins to be numbered
too high by 2. This also smashes the generation of
ADPCFG in dsPIC_PortSetting.m .

Bernard Leak

malife
Expert
Posts: 56
Joined: Tue Apr 17, 2007 7:24 am
Location: Santa Cruz, CA
Contact:

Re: ADC Input block

Post by malife » Sun Aug 31, 2008 6:45 pm

Hello Lubin,
I would also add to Bernard's post on the ADC the following bug:

I have AN channels 0-16 except for AN2 which is SPI1 SSL in 33FJ256MC710. So in the AN dialog box I have:

Code: Select all

[0 1 3 4 5 6 7 8 9 10 11 12 13 15 16]
Just for the sake of completeness I have a digital output block set with infinite sample time (so it just happens once) to high.

But regardless of that the generated code is as follows:

Code: Select all

/* Configuration ADCHS */
  AD1PCFGL = (0& 65535);
  AD2PCFGL = (0& 65535);
  AD1PCFGH = ((0 >> 16) & 65535);

  /* blocks with infinite sample periods */

  /* S-Function "dsPIC_Digital_OutputWrite" Block: <Root>/Drive SSL High */
  LATBbits.LATB2 = TRUE;
Which clearly ignores the fact that the ADxPCFGx bit 2 must be set to 1, in order to make B2 a digital pin. No show-stopper now that I know what the problem is but took me quite some time to figure out what was wrong :-).

Thanks, and I hope this gets corrected in the next version.

LubinKerhuel
Site Admin - Expert
Posts: 616
Joined: Wed Mar 07, 2007 11:23 pm
Location: Bayonne- France
Contact:

Re: ADC Input block - bug to solve

Post by LubinKerhuel » Mon Sep 01, 2008 9:50 pm

Hello,
Bernard Leak wrote:there is still a problem with the ADC Input block.

Bernard, For dsPIC33FJ256GP710, it gives the permitted
analogue input pins as 0-21 and 24-33, instead of
0-31 (which is certainly correct)
Thanks Bernard for this bug report. The definition (inside the blockset) for the dsPIC33FJxxxGP710 family has an error that may cause problems for ADC pins above 21. It is now corrected in the version 0.98fc of the blockset.

----
Malife,
I find a bug that may affect all PIC or dsPIC on the ADC block that may cause the trouble described.
The correction added in the version 0.98fc should solve it.
This bug has also been reported by Peter but by email.


Thanks for theses bug descriptions.
Lubin

Bernard Leak
Posts: 18
Joined: Fri Aug 15, 2008 3:42 pm
Location: Armitage, Staffordshire, England

Re: ADC Input block - solved

Post by Bernard Leak » Wed Sep 03, 2008 2:49 pm

Thanks: all my problems with the ADC block are now with the hardware!

Post Reply

Who is online

Users browsing this forum: No registered users and 17 guests