I2C and 24LC65

[aratti]

I wondered if that was the key to making my specific part work.

Although in this forum, I have read in several posts that I2CRead set the LSB to 1 automatically, I have never been able to read successfully, from external memory, without setting LSB to 1 myself. Now I do it as a standard in all my codes using I2C commands.

Al.

[Bill Legge]

I think your problem is with the address for READ and WRITE.

The 24LC64 EEPROM needs a WORD size address - even if the actual address is 0.

Change your program to

DEFINE B0 WORD ; Must not be a BYTE size or CONSTANT

B0 = 0
I2CWRITE, DataPin,ClockPin,$A0,B0,[Value]

and so on....

Good luck. I stuffed around with EEPROM for ages and eventualy found that all my errors were due to using BYTES when the chips expected a WORD. The spec sheet for the chip will tell you what it expects. The example in the PBP book is for a smaller EEPROM that only needs a BYTE address.

Regards Bill Legge

[afbecker]

Bill,

You are absolutely correct.

It came to me last night in a flash (pun intended.) I was re-reading the docs. and I realized I had defined the address variable as a byte type and the address of this part is a word type.

After I had changed it everything works superbly!

As a quick reply to Arratti: I am embarassed that I asked the question about the control word difference. At the time I replied I hadn't looked at the EPROM docs. for about two weeks. I forgot the difference in control words was due to the read/write mode.

Rhetorical question: Isn't it amazing how elementary a problem suddenly becomes once you have figured out the solution?