Which I2C address use?

Projects Networking, Protocols, and Devices
1

Hi there, I'm working on with an Arduino Mega 2560 and a C5515 eZdsp (from Texas Instruments) for a college project and I'm connecting the two boards via I2C.
The problem is I can't figure out which I2C address I have to use.
The Arduino is the slave and the C5515 the master. I read values from a pots and buttons from Arduino and sent them to the C5515 when it requests it (so I use the onRequest() function).

How can I know which address can I use?
I have tried an I2c scanner for Arduino and the results were:

I2C device found at address 0x18 !

I2C device found at address 0x2F !
I2C device found at address 0x3C !

From C5515 datasheet, 0x18 is for his oled, 0x3C for audio and 0x2F is not specified.
So I tried some addresses like 0x2F but the protocol doesn't work.
But just to try, I tried the 0x30 address and it worked for a while with some inestabilities and stoped working.

Also, I saw this address table (http://simplemachines.it/doc/IC12_97_I2C_ALLOCATION.pdf) but I don't understant it ... is this table for a general purpose of i2c protocol or is for a specific board?

Thank you in advance.

2

C5515 is master. On C5515 you should upload a program that defines which slave to communicate with. The other I2C adresses 0x18 and 0x3C are for slaves at the c5515 board. I do not think the pdf is relevant in this case.

3

Thanks for your response.
I've found the problem and a solution. The I2C was going crazy because at some point of the c5515 program it was doing a lot of requests in a small period, so I fixed it with a delay.
Now I'm using address 0x02 now and it works fine.