problems working with 24C512

[mister_e]

' ** Setup the I2C configuration **

Define I2C_SCLOUT 1 ' No need for the pullup resistor on the SCL pin

Not sure if it works without pull-up with this define...

BUT if you receive always 2, maybe you reverted your SDA, SCL line as well.. who knows?

[shaiqbashir]

Dear jerson and mister e

i have rechecked my connections, they are correct. I dont know where is the problem. I have even grounded WP which i havent done before. One more technical aspect that i want to tell you that i have connect WP and A0 and A1 directly to ground i.e. no pull down resistors. IS this making the problem. If any one of you have a working circuit of 24C512 with PIC, please send it so that i can rechecked my connections. Please send me coding as well.

[skimask]

no pull down resistors

Pull DOWN resistors? Don't remember anything about Pull DOWN resistors.

If any one of you have a working circuit of 24C512 with PIC, please send it so that i can rechecked my connections

The '512 datasheet I've got has a fairly good schematic. What's your datasheet say?

Please send me coding as well.

???????????????????????????????????????????????
Not asking for much eh?

[Jerson]

Are you sure your PIC is working? Any test pins that you can blink / toggle to make sure ? I think you have all the coding right including the pin config. I doubt your watchdog / brownout is killing the code execution. This can be ruled out if you can blink a test pin every time you read

[mat janssen]

Dear all,
If you read the datasheet of a 24C512 then you wil see this:

"device address,first word address,second word address,data"

so your line

EWrite:
I2CWRITE SDA,SCL,%10100000,Addr,[E_ByteOut]

is not correct
it must be
EWrite:
I2CWRITE SDA,SCL,%10100000,Addr1,[Addr2,E_ByteOut]
the same for I2CREAD
Don't forget to mark the read bit.

[mister_e]

mmm... not sure as the address is a WORD here and PBP handle the WORD variable for address. It always worked for me with the EEPROM i used, i've never use the C512, but C1024.

If by FIRST they mean Most Significant, it has to work, unless, yes you're in a kind of trouble... but this said, if you read the same way you write, you shouldn't have any problem huh?

For no reason, i stick to a swap of SDA & SCL pin idea and 1.8-4.7K pull-up on both pins.

[shaiqbashir]

thanks for your help

mat jensson you have raised a nice point here. I have tried almost every possibility in my coding as well as in my connections, but its not working at all. Please explain me your idea,
i mean what do u mean by marking the read bit? and how can i specify two addresses, can u explain me a bit.

One more thing that i want to share with u all. I get different numbers as output when i connect SDA SCL on different ports.


when i have

SDA = portB.1
SCL= portB.0
output= 2

SDA = portD.1
SCL= portD.0
output= 2

SDA = portC.1
SCL= portC.0
output= 8

I just couldnt get it.



Regards,

Shaiq Bashir