I2CRead & I2CWrite not working as expected

[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

[CuriousOne]

Pins are configured properly, LCD also working fine.

TRISA=%00000000  'SET A TO OUTPUT   
TRISC=%00001101   
TRISB=%00011000   
ANSELH=%00000000   ' ADC OFF B
ANSEL=%000000000 ' turn off ADC
ADCON1=%10000000  'adc justify
OSCCON=%01110101  'SET FREQUENCY TO 8MHZ
WPUB=%00000000    'turn off Pullups
CM1CON0=0         'DISABLE COMPARATORS
CM2CON0=0

This code works, if there is a number [99] or whatever in the write loop
If I modify that part to look like
I2CWRITE DPIN,CPIN,$A0,B0,[B1]
or any other variable instead of B1
all zeros get written into there, instead of actual variable value.

[richard]

This code works, if there is a number [99] or whatever in the write loop
If I modify that part to look like
I2CWRITE DPIN,CPIN,$A0,B0,[B1]
or any other variable instead of B1
all zeros get written into there, instead of actual variable value.

what code ?
minimal, complete and verifiable example MCVE , its not hard

this code

'*    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=$70
ANSELA=0
ANSELC=0
trisa.0=0
DEFINE I2C_SLOW 1 
ANSELA = 0
B0   Var word
b2 var byte
X var byte
SCL var Porta.2                     
SDA var Porta.1
lata.0=1
DEFINE DEBUG_REG PORTA
DEFINE DEBUG_BIT 0      ;  if not used for pwr  
DEFINE DEBUG_BAUD 9600
DEFINE DEBUG_MODE 0     
pause 2000
Debug 13,10,"Start",13 ,10
clear
For B0 = 0 To 15 
  b2=99+b0  
 I2CWRITE sda,scl,$A0,B0,[b2]  
 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

Start

0 99
1 100
2 101
3 102
4 103
5 104
6 105
7 106
8 107
9 108
10 109
11 110
12 111
13 112
14 113
15 114

[CuriousOne]

The code which I've posted, which writes 99 into eeprom.
I replace 99 with any other value - it works.
I put variable name into brackets - it writes zeroes into eeprom.
no matter what type of variable or what value do it has.