I2c write&read

[Melanie]

10K is also a little high... drop it by at least half to say 4K7.

[MINHLE]

Hello All,

the deviec is 16f628. the OSC 20Mhz (internal OSC, so R is ~10k-12K)
and the 24lc256 is BYTE SIZE. (32K X8 BIT)
the address is variable.

i will change to 4.7k and redefine eeprom address.

however the fuse defined: (work well )

OSC: INTRO CLOCKOUT
MCLR: INPUT PIN
(all other defined in the fuse window: marain unchange)

thank for all

regards,

[Gusse]

Hi MInhle,

Check the link and see the table.
I2CRead/I2CWrite part of PicBasic Pro manual

What is address size for over 24LC16 (2K bytes) devices?


BR,
-Gusse-

[MINHLE]

thank Gusse,

i replaced data address (I: in this case) by WORD . . and/or change R from 10K to 6K. ..it doesnot work.

(in the data sheet of 24lc256 dooesnot mention anything data address.

VOLTAGE drop across: R_SCL (10K or 6K) : ~5V (unchanged)
R_SDA (10K or 6K): ~2.5V

!! is it possible the EEPROM: DEATH??

[Gusse]

Hi MInhle,

If you are running with internal oscillator then speed is 4MHz, not 20MHz. Also you should tell that to compiler.

14.2.6 INTERNAL 4 MHZ OSCILLATOR
The internal RC oscillator provides a fixed 4 MHz
(nominal) system clock at VDD = 5V and 25°C, see
“Electrical Specifications” section for information on
variation over voltage and temperature.

DEFINE OSC 4

OSC: INTRO CLOCKOUT

14.2.7 CLKOUT
The PIC16F62X can be configured to provide a clock
out signal by programming the configuration word. The
oscillator frequency, divided by 4 can be used for test
purposes or to synchronize other logic.

CLKOUT is RA6, which is also your I2C data pin. Disable CLKOUT or change I2C data pin to other IO.

If you are not using comparator then disable those.

CMCON = 7

I hope these modifications will bring up some life to your EEPROM interface.

BR,
-Gusse-

[MINHLE]

hello GUSSE,

i got a BONUS now. the led is on (pin2 only) and flash

i lookk for error in teh program and let u knoow later

thanks for your help

[MINHLE]

HI Gusse,

the modifications were made.
as indicated.

defined OSC 4 ;no effect: ( INTCLOUT is set in the fuse window)
SDA PORTA.3
SCL PORRT.4
......

R_SDA & R_SCL: 4.5k
a led on portb flashed is due to error that i cannot see where it comes from


not write nor read. i assume EEPROM???