read slave address in iic(twi) using TWI_scanner example

[pavanvulichi]

hello,I am testing twi scanner example of nrf52dk.I want to read slave address, the sda & scl pins are 26 & 27 respectively. I am connected PCA9536 module as slave & address of that module is 0x41.I want to read slave address.I was successfully tested with arduino board & now i am testing with nrf52 dk. In arduino board the vdd is 3.5 v but in nrf52 dk the vdd is 2.85v & PCA9536 module will works for a range of 2.3 to 5.5 v so is there any possibility of voltage issue.can any one guided me how to read the slave address using TWI_scanner example code the error which i got is "NRF_ERROR_DRV_TWI_ERR_ANACK".

[endnode]

Do you have logic trace from I2C lines? I suspect that address coding is different then you expect so read attempt is sent "correctly" from nRF52 I2C Master and it is "correctly" ignored by PCA9536 I2C Slave. Be careful about 7-bit vs. 8-bit representation of I2C addresses, different documentation uses different notation... If it is not address issue then it can be anything else with SCL/SDA timing/coding, again looking to the signals on the lines should give you quick answer what.