I2C multi devices ?

Projects Networking, Protocols, and Devices
1

Hi,
I have a OBD-II Adapter I2C . with a tiny RTC I2C

I check the address of both device.
The RTC have 0x68 and the OBD2 have 0x62 ...

I can read the OBD2 info but not the RTC ...
If i unplug the OBD2 Wires i can read the RTC ...

here is a Scan of I2C devices

Scanning...
I2C device found at address 0x50 ! (Eprom)
I2C device found at address 0x62 ! (ODB2)
I2C device found at address 0x68 ! (RTC)
done

If someone have an idea ?

Thanks a lot.

2

can you post a schematic of how you did connect everything?
e.g. did you use pull up resistors?

3

First Thx for your fast reply !

Here is the Tiny RTC :

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First the Pull Up resistor is an simple Resistor or a specific resistor ?

Here is the 2 test i made.
The RTC module one the next picture is not the same i use. On the one i got there is 1 eeprom 24C32 witch use 0X50

1176×864 98 KB

1176×864 94.1 KB

So if i unplug the SDA SCL from OBD2 Module the RTC work Fine.
But i replug it only the OBD is reachable.

4

(what tool you used for the drawing?)

You need to have a 4K7 resistor between +5V and the I2C lines

Read the basics of I2C here - http://www.gammon.com.au/forum/?id=10896 - section - Pull-up resistors -

5

The soft is Fritzing

You can get it there : Download Fritzing

The resitor i tested was 4.7K I also test 10K

6

I recognized the lower two as fritzing, but the first one can fritizing do those too?

7

Fritzing can do kind of same.

try "EAGLE PCB Software"

or

"proteus"

8

I make another Test ... and i saw the 0x68 is use by both module...
RTC on the RTC module

and MPU6050 for the OBD2 :s ...