PCA9698DGG I2C address

[a_cavard]

Good morning,

In the PCA9698DGG expandor, II have connected AD0, AD1 and AD2 to Vss. I have checked my board and these 3 pins are OK to Vss.
So this component should be found at the 0x40 I2C address.
But it is found with the 0x20 address.

Do you have an idea about this difference of expected address ?

Best regards,
AC

[TomasVaverka]

Hi Alexandre,

Some functions require a 7-bit slave address and do a left shift by 1 bit + R/W bit. Then if you pass on 0x20 as a slave address, it will result in 0x40 for a write and 0x41 for a read. That is the only explanation that comes to my mind. The best would be to check it using an oscilloscope or a logic analyzer. I believe you would see 0x40 as a first byte.

Actually the addresses given in Table 12 represent 8-bit address including the Write (0) bit on LSB. In this case no left shift + R/W bit is needed.

Best regards,

Tomas

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