Simple Array Demo

[Archangel]

Still playing with and learning about arrays, mostly by trying to solve newbies problems. Here is a demo to write to and read from a 24LC01B I2C EEPROM using a 12F675. It outputs to a serial LCD.

' I2CREAD and I2WRITE Commands with External EEPROM on 12-bit core
'
' Write to the first 36 locations of External I2C EEPROM
' Read from eeprom and output sequentaly then as strings
' Tested on 12F675  using 24LC01B EEPROM
@ __config _INTRC_OSC_NOCLKOUT & _PWRTE_ON & _WDT_ON & _MCLRE_ON & _CP_OFF & _BODEN_OFF
DEFINE OSC 4
 
DEFINE DEBUG_REG	GPIO
DEFINE DEBUG_BIT	2
DEFINE DEBUGIN_BIT	5
DEFINE DEBUG_BAUD	2400
DEFINE DEBUG_MODE	0
DEFINE SHIFT_PAUSEUS 1000

EECON1   = 7  'Probably not needed here, enables internal eeprom
CMCON    = 7  'Disable comparators
ADCON0.0 = 0  'Disable A/D converters
ANSEL    = 0  'Disables Analog Select
DPIN var GPIO.0   'Assign Data pin
CPIN var GPIO.1   'Assign Clock pin
            ' a nice place to store things
B0 var byte
B1 var byte
B2 var byte
B3 VAR BYTE

GPIO   = 0 ' set port latches low
TRISIO = 0 ' set ports as outputs

pause 1000 ' Waste time while serial LCD initiailizes

For B2 = 0 To 35   ' counter for lookup table
lookup b2,["A","B","C","D","E","F","G","H","I","J","K","L","M",_
"N","O","P","Q","R","S","T","U","V","W","X","Y","Z","0","1","2",_
"3","4","5","6","7","8","9"],B0 ' store each char in b0 1 at a time

I2CWRITE DPIN,CPIN,$A0,B2,[ b0]  'write to 24C01 eeprom 1 character
Pause 20
Next B2       'next character write to eeprom
DEBUG 254,1   'clear LCD of any leftover data
loop:
DEBUG 254,1   'clears away the leftovers each loop

For B3 = 0 To 35   ' counter for reading 35 characters
I2CREAD DPIN,CPIN,$A0,b3,[B1]  ' read each character 1 at a time
pause 500           ' time to see each character on the LCD


DEBUG 254,2,"CHAR ",B1,"          " ' display the characters 1 at a time
'
Next B3                             ' get next character

I2CREAD DPIN,CPIN,$A0,0,[STR B1\20] ' read a string of  20 characters
DEBUG 254,2,STR B1\20               ' display those 20 characters
I2CREAD DPIN,CPIN,$A0,16,[STR B1\16]' get the last 16 characters
DEBUG 254,$C0,STR B1\16,"    "      ' display those 16 characters
DEBUG 254,$94,"I2C EEPROM DEMO"     ' display this program's purpose
DEBUG 254,$D4,"USING ARRAY & STRING" 
PAUSE 1500                          ' time to read the LCD
'NEXT B3                            ' go do it all again
Goto loop
end
POKECODE @$3FF, $4C  'read your PIC before erasing and put the cal. data here

[sougata]

Hi,

"A,B,C..." all have an ASCII value. For example "A"=65 so an iteration like this can help

For I = 0 to 25
char[I] = I + 65
Next I

P.S. PBP Manual has the ascii chart

[Archangel]

Hi,

"A,B,C..." all have an ASCII value. For example "A"=65 so an iteration like this can help

For I = 0 to 25
char[I] = I + 65
Next I

P.S. PBP Manual has the ascii chart

As I look at this a year later, I now understand what this snippet does.

"I realise there are likely easier ways to load the ARRAY . . .Baby Steps"

It loads the variable CHAR with the Alphabet,<font color = BLUE> A Belated Thanks, Sougata .</font color>
This response is to point that fact out to anyone new to arrays. Attention Newbies

[Bruce]

Joe,

Did you know you can do this?

Dat VAR BYTE
Alphabet VAR BYTE[26]

Main:
    FOR Dat = "A" to "Z"
     Alphabet[Dat-65]=Dat ' load Alphabet array 0-25 with A-Z
     HSEROUT [Alphabet[Dat-65],13,10]
     PAUSE 50
    NEXT Dat
    PAUSE 5000
    GOTO Main
    
    END

[Archangel]

Joe,

Did you know you can do this?

Dat VAR BYTE
Alphabet VAR BYTE[26]

Main:
    FOR Dat = "A" to "Z"
     Alphabet[Dat-65]=Dat ' load Alphabet array 0-25 with A-Z
     HSEROUT [Alphabet[Dat-65],13,10]
     PAUSE 50
    NEXT Dat
    PAUSE 5000
    GOTO Main
    
    END

Woo Hoo, another tidbit of knowledge! I did not know that.
Thank You Bruce.
JS