cancel
Showing results for 
Search instead for 
Did you mean: 

I2C EEPROM and External SRAM as Data Memory

jki79ros81
Associate II
Posted on December 18, 2008 at 04:04

I2C EEPROM and External SRAM as Data Memory

13 REPLIES 13
hervett
Associate II
Posted on May 17, 2011 at 12:55

I don't understand because when I watch SDA and SCL on the oscilloscope when I execute send7bitadress in a while(1) I have always a bit ( don't know wich, first or last or other) at 1. I thought at the beginning that was my ACK from the EEPROM and I was happy of that, but I've changed EEPROM adress in sned7bitadress and I have still that bit ( sent 0x00 for EEPROM slave adress). I'm watching since this morning all the topics about I2C and EEPROM, and there are a lot, and I can't fix problems because I'm stop for the test of EV6. If Lanchon is not far of this topic, I think he will help me. Or if someone has just code because I'm ###!!???$$¤¤^^%%*** !!!

Thank you :D

hervett
Associate II
Posted on May 17, 2011 at 12:55

It's ok now, I understood where was my problem. My program stopped on the checking of EV6 because my EEPROM was DEAD !!! GRRRRRR, I changed the EEPROM and now I can Write on it without troubles on the chekings of EV5,6,8 ...... I don't know now if the write is ok, but at least the communication works between STM32 and EEPROM, I find happiness where it is !

And it answer to my question if the checking of EV6 check the ACK too, and yes. I did test with the adress of the EEPROM. Now i will continue !

jj
Associate II
Posted on May 17, 2011 at 12:55

@hervett-

Good for you - but always blame the IC last! Is it possible that the eeprom was a 5V device - and didn't reliably ''see'' your 3V3 SDA/

SCL signals?

For the record - tell us what you are using for the eeprom address. I will
hervett
Associate II
Posted on May 17, 2011 at 12:55

Hi !

My EEPROM accept 3,3V, but i think I destroyed it myself. Now I have my 24C32 plugged to my STM32, and I can write on my EEPROM. My EEPROM slave adress is 0xA0 ( E0, E1 and E2 of EEPROM at VSS ). When I'm using send7bitaddress with my EEPROM slave adress, the checking of EV6 is ok and my program continue. But when I give an other address like 0xA3 or 0xA6, the checking of EV6 is not good and failed.

Now my problem is that the checking of EV6 during my reading of the EEPROM don't work, I will see that today.

bye