Problem with I2Cread and I2CWRITE function

[mat janssen]

Maybe you forgot 2 resistors ?? From SDA to Vcc and SCL to Vcc (4K7)

[Tony85]

Between 16F877 SDA pin and 24LC64 SDA pin I have a 330Ohms resistor and Between 16F877 SCL pin and 24LC64 SCL pin I have a 330Ohms resistor.

[mat janssen]

These are serie resistors, that is no problem. But you must put also 2 resistors from 4K7 to the + power of the PICCHIP and the SDA and SCL line. Kind of pullup resistors.

[Tony85]

as this ?

http://col2000.free.fr/copieur/cop-sche.gif

[mat janssen]

You used 10K resistors, lower them to 4K7. And put also a capacitor of 100 nF over each supply point of each ic, near each ic.
Is your oscillator running well? Because normally I put 22pF capacitors at a 4 MHz cristal.
Put also an extra elco (10uF) and a capacitor of 330nF near your 7805. This prevents oscillating of this component.

[Tony85]

I just have put 4.7k resistor and it work good

Thanks a lot

Tony

[mat janssen]

You'r welcome.
M