18F2431 Learning Curve

[Aussie Barry]

Hi All,

I got my 18F2431 today and I am trying to learn how to fly it.
I thought I would start with a very simple LCD routine:

'****************************************************************
'*  Name    : LCD_18F2431                                      *
'*  Author  : Barry Phillips                                    *
'*  Notice  : Copyright (c) 2012 Baztronics                     *
'*          : All Rights Reserved                               *
'*  Date    : 22/06/2012                                        *
'*  Version : 1.0                                               *
'*  Notes   : LCD test program for 18F2431                                                *
'*          :                                                   *
'****************************************************************

' Define LCD registers and bits
Define	LCD_DREG	PORTB
Define	LCD_DBIT	0
Define	LCD_RSREG	PORTB
Define	LCD_RSBIT	5
Define	LCD_EREG	PORTB
Define	LCD_EBIT	4
Define	LCD_BITS	4
Define	LCD_LINES	2

Mainloop:
LCDOUT  $FE, $01                    ' Clear screen
LCDOUT  $FE, $80, "Hello World"
Pause 1000                          ' Pause 1 second
LCDOUT  $FE, $C0, "Hello Again"
pause 5000                          ' Pause 5 seconds
goto Mainloop                       ' Loop forever

When I tried to complie the program I get the following error messages

[ASM WARNING] Invalid RAM location specified. (0) : Warning [219]

repeated 13 times.

I was expecting a severe learning curve with this new device but I would have thought something as simple as this would have been straight forward.

Can someone please enlighten me on what needs to be done to correct this problem?

Cheers
Barry
VK2XBP

[Aussie Barry]

Update:

It was a very long day yesterday!
I realised this morning that I had the wrong device selected in MCS. It compiles now but there ares still problems.
I did see "Hello World" appear on the first line of the LCD but it took a couple of seconds to get there...and it only happened once.
I obviously have the set-ups all messed up. I can't even do a simple LED Blink on RC0

Back to the datasheet.

Cheers
Barry
VK2XBP

[Demon]

Oscillator speed?

Or is that not required any more with v3.0 (I'm still on v2.60).

Robert

[Aussie Barry]

I am using the internal oscillator which defaults to 8MHz
I also tried the program with

DEFINE OSC 8

preceeding the LCD definition statements, all to no avail

I was even more disappointed that my Blinky LED program didn't work

TRISA = 0               ' Set PORTA as output

LED    VAR  PORTA.0     ' Assign name "LED" to PORTA.0

mainloop:
   High LED             ' Turn on LED connected to PORTA.0
   Pause 500            ' Delay for .5 seconds

   Low LED              ' Turn off LED connected to PORTA.0
   Pause 500            ' Delay for .5 seconds

   Goto mainloop        ' Go back to loop and blink LED forever
   
   End

I have +5V connecteds to pins 7 and 20 (AVdd and Vdd) and 0V connected to pins 8 and 19 (AVss and Vss). I have a 10k pull-up resistor from MCLR (Pin 1) to +5V and 330R in series with LED connected from RA0 (Pin 2) to 0V. I even tried fliping the LED just in case I put it in backwards!

Any ideas on why this thing won't work as expected?
Perhaps the default for RA0/AN0 is an analog input pin? I thought the TRISA = 0 statement would overide...

Cheers
Barry
VK2XBP

[mackrackit]

How are the configs setup?

[Demon]

I always stay away from analog pins until I get a basic program running.

Robert

[ScaleRobotics]

Hi Barry,

To include your configs in your pbp 3.0 code is pretty easy. Here are some examples: http://www.picbasic.co.uk/forum/show...963#post110963

The bare bones ones to include would be these (though I have not tried running it on internal yet): Note it defaults to 4 mhz, unless you set the oscon bits for something else.

  #CONFIG
    __CONFIG    _CONFIG1H, _OSC_IRCIO_1H
    __CONFIG    _CONFIG2H, _WDTEN_ON_2H & _WDPS_512_2H
    __CONFIG    _CONFIG4L, _LVP_OFF_4L

  #ENDCONFIG

ADCON0 = %00000000
ADCON1 = %00000000

[rsocor01]

Include the line

DEFINE OSC xx

And set all the options to disable (watchdog, brown-out, etc) to start with.

Robert

[HenrikOlsson]

Hi,
Here are the CONFIGs I use for my 2431:

#CONFIG
    CONFIG OSC = HSPLL
    CONFIG FCMEN = ON
    CONFIG IESO = OFF
    CONFIG PWRTEN = ON
    CONFIG BOREN = ON
    CONFIG BORV = 42
    CONFIG WDTEN = OFF
    CONFIG WDPS = 512
    CONFIG WINEN = OFF
    CONFIG PWMPIN = OFF
    CONFIG LPOL = HIGH
    CONFIG HPOL = HIGH
    CONFIG T1OSCMX = OFF
    CONFIG MCLRE = ON
    CONFIG STVREN = ON
    CONFIG LVP = OFF
    CONFIG DEBUG = OFF
    CONFIG CP0 = ON
    CONFIG CP1 = ON
    CONFIG CP2 = ON
    CONFIG CP3 = ON
    CONFIG CPB = OFF
    CONFIG CPD = OFF
    CONFIG WRT0 = OFF
    CONFIG WRT1 = OFF
    CONFIG WRT2 = OFF
    CONFIG WRT3 = OFF
    CONFIG WRTC = OFF
    CONFIG WRTB = OFF
    CONFIG WRTD = OFF
    CONFIG EBTR0 = OFF
    CONFIG EBTR1 = OFF
    CONFIG EBTR2 = OFF
    CONFIG EBTR3 = OFF
    CONFIG EBTRB = OFF
#ENDCONFIG

If you're running on the internal oscillator then you need to change from HSPLL to IRCIO.

The oscillator section of the datasheet indicates that the internal oscillator defaults to 4Mhz but looking at the initialization condition of the OSCCON register it seems like bits 4,5,6 are all zero on power up - which would give you 31kHz. If you then have the clock DEFINED to 8MHz your 500ms PAUSE will actually be 322 seconds....

So, without actually testing this I'd try something like

DEFINE OSC 8
OSCCON = %01110010   ' Internal oscillator, 8MHz

/Henrik.

[Aussie Barry]

Thanks Henrik.

There is SO MUCH in the datasheet for this device!
Just when you think you have everything under control, something else raises its ugly head

I will try your configs and recommended changes over the next 24-48 hours and report back - hopefully with good news.

I went out this afternoon and bought a couple of crystals to play with - just in case. I now have 4, 8 and 20Mhz crystals to plug in, if and when required.

Cheers
Barry
VK2XBP

[Aussie Barry]

Hi Henrik,

I am pleased to advise that I now have a simple LCDOUT and LED Blink program operating as expected.
When I went through the '2431 datasheet regarding OSCON Register I selected OSCON = %0111110 which is somewhat different to what you suggested.
Both work but I am curious to know how, when and why bits 0-3 of the OSCON register should be used. Any comments?

My next stage of experimentation will be to get the serial LCD display working in the background using the HSEROUT statement. From there I will move onto ADCin to read a pot and follow up with the HPWM command.

Progress is slow but I am trying to understand "why" things are the way they are in conjunction with learning "how" to do things.

Cheers
Barry
VK2XBP