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jRn
Associate II
March 8, 2022
Question

M24C02-FMH6TG: I2C Adresses in e.g. Linux is not fixed?

  • March 8, 2022
  • 3 replies
  • 2175 views

Hello Team,

we have a board with 5x I2C devices on it. So far it works fine but we have a strange effect.

We have 1x M24C02-FMH6TG (0x50 --> fixed??) and 1x M24C64-DFMC6TG (0x54 -> fixed!) from STM

Additionally we have further devices like temperature sensor (0x4A), RTC (0x51) and SEC (0x48).

So in Linux we are doing a i2c address scan and suddenly we have the address 0x50 until 0x57 in our system. After removing the M24C02-FMH6TG the right 4 i2c-address are shown in the system.

If the M24C02-FMH6TG is placed we also have access on the other EEPROM and RTC as well. But it shown more i2c addresses.

What kind of effect does the M24C02-FMH6TG have. At this IC it is not possible to configure the i2c address externally.

Best regards,

Juergen

This topic has been closed for replies.

3 replies

Pierre P.
ST Employee
March 8, 2022

Hello Juergen,

We don't recommend to share the I2C bus with other sensors when M24C02-FMH6TG is mounted.

Indeed, as you have guessed, this one could also answer also to 0x50 to 0x57.

Sorry for inconvenience.

Br

Pierre P.

jRn
jRnAuthor
Associate II
March 8, 2022

Hello Pierre,

thanks for the feedback, but were can i found such an information? There is no further information about this in the datasheet.

Thanks!

Br

Juergen

Pierre P.
ST Employee
March 8, 2022

A new release of M24C02 datasheet will mention this point.

(FYI: M24C04/08/16 have also same behavior)