I2CRead & I2CWrite not working as expected

[CuriousOne]

Here is full complete code.

;----[16F886 Hardware Configuration]--------------------------------------------
#CONFIG
cfg1 = _INTRC_OSC_NOCLKOUT    ; INTOSCIO oscillator: I/O function on RA6/OSC2/CLKOUT pin, I/O function on RA7/OSC1/CLKIN
cfg1&= _WDT_ON                ; WDT enabled
cfg1&= _PWRTE_OFF             ; PWRT disabled
cfg1&= _MCLRE_OFF             ; RE3/MCLR pin function is digital input, MCLR internally tied to VDD
cfg1&= _CP_OFF                ; Program memory code protection is disabled
cfg1&= _CPD_OFF               ; Data memory code protection is disabled
cfg1&= _BOR_OFF               ; BOR disabled
cfg1&= _IESO_ON               ; Internal/External Switchover mode is enabled
cfg1&= _FCMEN_ON              ; Fail-Safe Clock Monitor is enabled
cfg1&= _LVP_OFF               ; RB3 pin has digital I/O, HV on MCLR must be used for programming
cfg1&= _DEBUG_OFF             ; In-Circuit Debugger disabled, RB6/ICSPCLK and RB7/ICSPDAT are general purpose I/O pins
  __CONFIG _CONFIG1, cfg1


cfg2 = _BOR40V                ; Brown-out Reset set to 4.0V
cfg2&= _WRT_OFF               ; Write protection off
  __CONFIG _CONFIG2, cfg2


#ENDCONFIG


'chip configs
TRISA=%00000000  'SET A TO OUTPUT   1=input
TRISC=%00001101   'set half C for in/out
TRISB=%00011000   'set PortB to output
ANSELH=%00000000   ' ADC OFF B
ANSEL=%000000000 'configure PortA as digital except first 2
ADCON1=%10000000  'adc justify
OSCCON=%01110101  'SET FREQUENCY TO 8MHZ
WPUB=%00000000    'turn off Pullups
CM1CON0=0         'DISABLE COMPARATORS
CM2CON0=0         'SAME HERE
'CCP1CON=%01000000 ' configure pwm
'PSTRCON=%00010110 'disable C pwm


DEFINE OSC 8   
DEFINE ADC_BITS 10
DEFINE ADC_CLOCK 3
DEFINE ADC_SAMPLEUS 50
'lcd config
pause 200
' Set LCD Data port 
DEFINE LCD_DREG PORTC  
DEFINE LCD_DBIT 4  
DEFINE LCD_RSREG PORTB  
DEFINE LCD_RSBIT 0  
DEFINE LCD_EREG PORTB  
DEFINE LCD_EBIT 1  
DEFINE LCD_BITS 4  
DEFINE LCD_LINES 2  
DEFINE LCD_COMMANDUS 1500  
DEFINE LCD_DATAUS 44
define i2c_slow 1




DPIN Var PORTA.2       ' I2C data pin
CPIN Var PORTA.1       ' I2C clock pin
B   Var word
B1   Var byte
B2   Var byte


For B = 0 To 15 
  b1=99+b 
 I2CWRITE dpin,cpin,$A0,B,[b1]  
 Pause 10        '
Next 
pause 100


mainloop:


   For B = 0 To 15   
     I2CREAD DPIN,CPIN,$A0,B,[b2]  
     lcdout $fe, $1, dec b, " ", dec b2 
     pause 1000
   Next 
 
   Goto mainloop
 
   End

And funny thing happens - the returned value of B2, as shown on display, is 114! for all 16 locations.
looks like 1st loop executed before writing to EEPROM ?

[CuriousOne]

Maybe read routine is faulty?

[CuriousOne]

yes it is read routine - it reads eeprom only once.

[richard]

works perfectly on simulator

had to increase some delays for slow old lcd
pause 1000
' Set LCD Data port
DEFINE LCD_DREG PORTC
DEFINE LCD_DBIT 4
DEFINE LCD_RSREG PORTB
DEFINE LCD_RSBIT 0
DEFINE LCD_EREG PORTB
DEFINE LCD_EBIT 1
DEFINE LCD_BITS 4
DEFINE LCD_LINES 2
DEFINE LCD_COMMANDUS 2000
DEFINE LCD_DATAUS 44
lcdout $fe, $1, "ready " ;added to prove lcd working
pause 1000

[CuriousOne]

I will use everything different - LCD, PIC, EEPROM and will check again...