I2C blues

[Charles Linquis]

http://www.mcc-us.com/MIIC-101-DS.htm

[Bill Legge]

CL,

Thanks - I've had a look at the site/product - a bit pricey for me as only an occasional/hobby I2C user. The Australian magazine 'Silicon Chip' had an I2C analysis board as a do-it-yourself project about a year ago. It used pretty mendane chips and some free Phillips software; I must give it a go.

Can you run your system at 10MHz and see if that does the trick?

Please let us know when/if you get it going. I spent ages getting familiar with EEPROM I2C and would like to learn what the problem was.

Regards Bill legge

[mackrackit]

Hey Charles,

If you are still having trouble try changing EEADR to %10100000 and to tie A0,A1, and A2 on the eeprom chip to ground.

If that does not work then try it with and without the I2C_slow setting.

[Charles Linquis]

I talked the customer out of the feature that required it, so I just moved on. I'll get back to it later.

I was going to use the EEPROM as a "dual port RAM". The customer wanted to write data to me via I2C, so my PIC would have had to be an I2C slave. Rather than go through the hassle of that, I was just going to have them write to my EEPROM (they had access to the same SCL and SDA lines), and then I would occasionally read the same location. If I got an error during read (because they were writing at the same time), I would just read again. I told the customer that they would have to verify every read that they did. Since the data changed only every few seconds, I figured that this was a great way to get the job done.

Until I found that I couldn't write to or read from my own EEPROM!

I'll let you know what I find. It will be a few days before I get back to this.