I2CRead & I2CWrite not working as expected

[CuriousOne]

Here I connected the scope.
This is how this code looks:
My scope (Hantek DSO2D10) Has I2C decode function, but I can't get it running properly.

mainloop:


   For B0 = 0 To 15 step 2  
     I2CREAD DPIN,CPIN,$A0,B0,X  
     lcdout $fe, $1, dec b0, " ", dec X 
     pause 1000
   Next B0


Goto mainloop

[CuriousOne]

Oh by the way, I swapped chip with 24C04N - no difference.

[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