PIC 18F4550 and MCP23017

[mackrackit]

I have not played with USB much.
This is something I will study from.
Thanks

[artha2]

Hey Dave,
Im trying to use 16f877a with macp23017, but I wasn't successful.
I define the mcp23017 register, but when I want to compile my program it gives me error.
I tried to use your program and learn from it but I had no success, I noticed you are using some include file that I dont have them.
I have 16 led on each port would you please help me?

'*  Notes   :  XT 4Mhz                                          *
'*          :                                                   *
'****************************************************************
'Includes 
include "modedefs.bas" 
'****************************************************************
'Definitions
DEFINE I2C_SDA PORTc,4 
DEFINE I2C_SCL PORTc,3   
'****************************************************************
'Variables
a var byte
chip1 var byte
chip2 var byte
chip3 var byte
chip4 var byte         
'****************************************************************
'Alias
CP VAR PORTc.3
DP VAR PORTc.4
                         
'****************************************************************
'Initialization

    'Pic 16f877A
option_reg.7 = 0 'portb pullups enabled         
SSPSTAT=%00111101
'SSPCON1=%00101111
SSPCON2=%00000001

    'MCP 23017

IODIRA Con $00
IODIRB con $00
IPOLA con $00
IPOLB con $00
GPINTENA con &00
GPINTENB con $00
DEFVALA con $00
DEFVALB con $00
INTCONA con &00
INTCONB con &FF
IOCON con %00001000
GPPUA con $00
GPPUB con $00
INTFA con $00
INTFB con $00
INTCAPA con &00
INTCAPB con &00
GPIOA con $00
GPIOB Con $FF
OLATA con $00
OLATB con &FF  

'****************************************************************
'set ports   
     trisa=%00000000             
     trisc=%00000000     
     pause 500                 
     goto start          
start:
    porta.5 = 1
    portc.7=0
    pause 500
    porta.5 = 1
    portc.7=1
    pause 500
    I2CWRITE dp,cp,$00,chip1,[%00000000] 'one-shot sample
    pause 200
    I2CWRITE dp,cp,$00,chip1,[%11111111] 'one-shot sample 
    pause 200
    I2CWRITE dp,cp,$00,chip1,[%00000000] 'one-shot sample
    pause 200
    I2CWRITE dp,cp,$00,chip1,[%11111111] 'one-shot sample 
    pause 200
     goto start   
end

[DaveC3]

What errors are you getting?

The include files are for USB

Dave

[artha2]

Thanks Dave,

before i used to define 16f877a register like ( adcon = $82), so i thought it should be same to define mcp registers like (IODIRA = $00 to make my mcp port a as output), I got my first error there ( syntax error, red color on my whole line) then I saw that you define by constant. so i changed my method and followed you and defined the by using "con". but something happens that I dont understand it gives me error when i define GPINTENA con &00, but it accepts GPINTENB con &00 after seeing this I told myself ok im going to use assembly language and i will insert it to my Picbasic as a sub routin. I know that i have to Equate all register and variable like ( eecon1 equ h'08' ) but I think those are for my pic and i dont know how i shoud have access to MCP register to for example turn the pull ups on or off
I think I'm totally lost. I thought that i define my chip one time (which pin is input and which one output, interrupts, pull ups,..., and then I can use I2CWRITE and read command to send my bytes to the outputs and then read from it.
how would you do that?

Thanks for your time, I really appreciate it
Artha

[DaveC3]

I think you have a typo error

GPINTENA con &00 should be GPINTENA con $00

Try that

Dave

You also need to initialize the MCP23017

InitMPC23017:
Pause 100
'#############  PORTA
i2cwrite  PortA.0,PortA.1,IO_EXP0WR,[IOCONA,IOCONSETA]
i2cwrite  PortA.0,PortA.1,IO_EXP0WR,[IODIRA,$0]          'PortA inputs
i2cwrite  PortA.0,PortA.1,IO_EXP0WR,[IOLATA,$FF]            'PortA = 0
'i2cwrite  PortA.0,PortA.1,IO_EXP0WR,[IPOLA,0]
'i2cwrite  PortA.0,PortA.1,IO_EXP0WR,[DEFVALA,0]
'i2cwrite  PortA.0,PortA.1,IO_EXP0WR,[GPPUA,$FF]           'pull-ups enabled
'i2cwrite  PortA.0,PortA.1,IO_EXP0WR,[INTCONA,0]
'i2cwrite  PortA.0,PortA.1,IO_EXP0WR,[GPINTENA,$FF]        'interupt on change
'##############  PORTB
i2cwrite  PortA.0,PortA.1,IO_EXP0WR,[IOCONB,IOCONSETB]
i2cwrite  PortA.0,PortA.1,IO_EXP0WR,[IODIRB,0]
i2cwrite  PortA.0,PortA.1,IO_EXP0WR,[IOLATB,$FF]
'i2cwrite  PortA.0,PortA.1,IO_EXP0WR,[IPOLB,0]
'i2cwrite  PortA.0,PortA.1,IO_EXP0WR,[DEFVALB,0]
'i2cwrite  PortA.0,PortA.1,IO_EXP0WR,[INTCONB,0]
'i2cwrite  PortA.0,PortA.1,IO_EXP0WR,[GPINTENB,0]
return
ReInitPortA:
i2cwrite  PortA.0,PortA.1,IO_EXP0WR,[IOCONA,IOCONSETA]
i2cwrite  PortA.0,PortA.1,IO_EXP0WR,[IODIRA,$FF] 
i2cwrite  PortA.0,PortA.1,IO_EXP0WR,[GPPUA,$FF]           'pull-ups enabled

return

[artha2]

Hey Dave, thanks man
you were right i made that mistake and i looked over and i couldn't catch it, you are having good eyes (i fixed it now).
but still there is no success. even i copy you code and deleted you usb codes line and compile it but i could not get it to work.
I connect all three address pin for my MCP to ground
I pulled up mcp reset pin with a 15K R
I pulled up SDA and SCL pin with two 1k R
portc.3 is my clock and portc.4 is my data
portc.7 is connected to an led just for test, so i know where i am in the program
and this is my codes

again thanks for your time

'* Notes : *
'* : *
'************************************************* ***************
'Includes
include "modedefs.bas"
'************************************************* ***************
'Definitions
DEFINE I2C_SDA PORTc,4
DEFINE I2C_SCL PORTc,3
define ADC_BITS 10
define ADC_CLOCK 3
define ADC_SAMPLEUS 50

'************************************************* ***************
'Variables
A var byte
Chip1 var byte
POT1 var word
POT2 var word

'************************************************* ***************
'Alias
CP VAR PORTc.3
DP VAR PORTc.4

'************************************************* ***************
'Initialization

'Pic 16f877A
adcon1=$02 'left justify A0 and A1
CCP1CON=0 'disable capture/compare
CCP2CON=0
CMCON=7 'disable comparater
option_reg.7=0 'portb pullups enabled

'set ports
trisa=%11111111
trisb=%00000000
trisc=%00000000
trisd=%00000000

'MCP 23017
chip1 = $40
IODIRA con $FF ' port A output
IODIRB con $FF ' port B output
IOCON con $3C ' Defining the MCP Bank as 0 and sequential disable

MCPA con $12
MCPB con $13
MCPAL con $14
MCPBL con $15

'Initialing MCP

i2cwrite dp,cp,$0A,chip1,[iocon]
i2cwrite dp,cp,$0B,chip1,[iocon]
i2cwrite dp,cp,$00,chip1,[iodira]
i2cwrite dp,cp,$01,chip1,[iodirb]



'IODIRA Con $00
'IODIRB con $00
'IPOLA con $00
'IPOLB con $00
'GPINTENA con $00
'GPINTENB con $00
'DEFVALA con $00
'DEFVALB con $00
'INTCONA con $00
'INTCONB con $FF
'IOCON con %00001000
'GPPUA con $00
'GPPUB con $00
'INTFA con $00
'INTFB con $00
'INTCAPA con $00
'INTCAPB con $00
'GPIOA con $00
'GPIOB Con $FF
'OLATA con $00
'OLATB con $FF)

'************************************************* **************
'Main Program

start:
portd =$00
portc.7=0
pause 500
portd = $ff
portc.7=1
pause 500
portc.7=0
pause 500
'I2CWRITE DataPin,ClockPin,Control,{Address,}[Value{,Value...}]{,Label}
I2CWRITE dp,cp,mcpa,chip1,[$FF] 'porta on
portc.7=1
pause 200
I2CWRITE dp,cp,mcpa,chip1,[$00] 'porta off
portc.7=0
pause 200
I2CWRITE dp,cp,mcpal,chip1,[$FF] 'porta on
portc.7=1
pause 200
I2CWRITE dp,cp,mcpal,chip1,[$00] 'porta off
portc.7=0
pause 200
I2CWRITE dp,cp,mcpb,chip1,[$FF] 'portb on
portc.7=1
pause 200
I2CWRITE dp,cp,mcpb,chip1,[$00] 'portb off
portc.7=0
pause 200
I2CWRITE dp,cp,mcpbl,chip1,[$FF] 'portb on
portc.7=1
pause 200
I2CWRITE dp,cp,mcpbl,chip1,[$00] 'portb off
portc.7=0
pause 200

goto start
end

[DaveC3]

The smallest resister I have used for I2C is 4.7K, also you need to initialize the MCP23017 correctly.


Also you have set your port direction to input
IODIRA con $FF ' port A output
IODIRB con $FF ' port B output

to make the port output you need to change the $FF to $00, just like setting a port direction in a PIC.

Good luck

Dave