I2CRead & I2CWrite not working as expected

[CuriousOne]

I set up I2C capture and it looks suspicious.
The 1st entry at "data" is actually and address of the chip
and 3rd entry - the address I'm sending to it for reading
but I'm getting no response?

[richard]

yet still another pointless snippet , with nothing defined

I2CREAD DPIN,CPIN,$A0,B0,X

you persist in using incorrect syntax , it should be

I2CREAD DPIN,CPIN,$A0,B0,[X ]



proper code, not snippet with undefined rubbish, its not hard

#CONFIG             __config        _CONFIG1,    _FOSC_INTOSC & _CP_OFF & _WDTE_OFF &  _PWRTE_ON  &  _MCLRE_ON  & _CLKOUTEN_OFF
              __config      _CONFIG2, _PLLEN_ON & _LVP_OFF
#ENDCONFIG
;pic16f1825

DEFINE OSC 32
OSCCON=$70
ANSELA=0
ANSELC=0
trisa.0=0
DEFINE I2C_SLOW 1 
ANSELA = 0
a Var Byte
addr Var word
ar Var Byte


SCL var Porta.2                     
SDA var Porta.1
lata.0=1
DEFINE DEBUG_REG PORTA
DEFINE DEBUG_BIT 0      ;  if not used for pwr  
DEFINE DEBUG_BAUD 9600
DEFINE DEBUG_MODE 0     
pause 2000
Debug 13,10,"Start",13 ,10


a=20
addr=$200
I2cwrite Sda,SCL,$a0 ,addr,[a]
pause 10


addr=$200
I2CREAD Sda,SCL,$a0 ,addr,[ar ]
debug 13,10,sdec ar
end

what a write looks like



what a read looks like

[CuriousOne]

Well, if there's syntax error, compiler should warn about it, right?

[CuriousOne]

I tried to add brackets and now it starts working, but in the weird way.

I2CWRITE DPIN,CPIN,$A0,B0,[127]
Writes 127 into eeprom
but if I substitute variable there, no matter, byte or word
after reading, I'm getting zeroes.

[richard]

Well, if there's syntax error, compiler should warn about it, right?

no the compiler produces code to I2CREAD DPIN,CPIN from device $A0 @eeprom address B0,X then read nothing as asked for
there is no error

I tried to add brackets and now it starts working, but in the weird way.


I2CWRITE DPIN,CPIN,$A0,B0,[127]
Writes 127 into eeprom
but if I substitute variable there, no matter, byte or word
after reading, I'm getting zeroes.

produce a compliable example that demonstrates the problem

[CuriousOne]

DPIN Var PORTA.2       ' I2C data pin
CPIN Var PORTA.1       ' I2C clock pin
B0   Var word
B1   Var byte
B2   Var byte
X var byte
x=0


   For B0 = 0 To 15    
   b1=b2
     I2CWRITE DPIN,CPIN,$A0,B0,[99]  
     Pause 10        '
pause 100 
   Next B0


mainloop:


   For B0 = 0 To 15   
     I2CREAD DPIN,CPIN,$A0,B0,[X]  
     lcdout $fe, $1, dec b0, " ", dec X 
     pause 1000
   Next B0
 
   Goto mainloop
 
   End

[richard]

DPIN Var PORTA.2       ' I2C data pin
CPIN Var PORTA.1       ' I2C clock pinB0   Var wordB1   Var byteB2   Var byteX var bytex=0   For B0 = 0 To 15       b1=b2     I2CWRITE DPIN,CPIN,$A0,B0,[99]       Pause 10        'pause 100    Next B0mainloop:   For B0 = 0 To 15        I2CREAD DPIN,CPIN,$A0,B0,[X]       lcdout $fe, $1, dec b0, " ", dec X      pause 1000   Next B0    Goto mainloop  

End

so we guess whats wrong then

DPIN,CPIN are analog
the chip[undefined] has no porta
the vcc is too low
the clock is too fast
the lcd is not setup properly
the config settings are incorrect
the interrupt in the unseen part of the code is ruining the timing
what's the point

[richard]

this

'*    pic16f1825      :  eprom addr =$a0   
#CONFIG
             __config        _CONFIG1,    _FOSC_INTOSC & _CP_OFF & _WDTE_OFF &  _PWRTE_ON  &  _MCLRE_ON  & _CLKOUTEN_OFF
              __config      _CONFIG2, _PLLEN_ON & _LVP_OFF
#ENDCONFIG


DEFINE OSC 32
OSCCON=$70
ANSELA=0
ANSELC=0
trisa.0=0
DEFINE I2C_SLOW 1 
ANSELA = 0
B0   Var word
X var byte
SCL var Porta.2                     
SDA var Porta.1
lata.0=1
DEFINE DEBUG_REG PORTA
DEFINE DEBUG_BIT 0      ;  if not used for pwr  
DEFINE DEBUG_BAUD 9600
DEFINE DEBUG_MODE 0     
pause 2000
Debug 13,10,"Start",13 ,10
clear
For B0 = 0 To 15 
 I2CWRITE sda,scl,$A0,B0,[99]  
 Pause 10        '
Next B0
pause 100
mainloop:
    For B0 = 0 To 15   
     I2CREAD sda,scl,$A0,B0,[X]  
     debug 13,10, dec b0, " ", dec X 
    Next B0 
    pause 1000
Goto mainloop
end

produces as expected this

Start


0 99
1 99
2 99
3 99
4 99
5 99
6 99
7 99
8 99
9 99
10 99
11 99
12 99
13 99
14 99
15 99