ADAU1701 Starting problems

Hello Analog Devices and followers,

I'm a complete DSP NOOB and wanted to start exploring the world of dsp and digital audio and decided to build my own pcb around the ADAU1701 dsp. I studied several evaluation boards and made a pcb based on the attached schematics.

For now with this pcb i wanted to test with analog (mic) input and speaker output to test some filters. And play around with digital audio in and out.

After building the board i seem to have a problem but i can't find what i'm doing wrong. Connecting to the USBi interface i cannot connect to the ADAU1701. I keep getting a message of a failure connecting with USB and a COMMS FAIL. Being used to analog designs it was easy to follow signals and find the problem but with this design i don't know what to check anymore.

The MCLK is looking good, the 3.3V and 1.8V are good. Looking at the I2C signals i first had a problem (SCL was grounded) but this was easy solved. Now i see both (SCL & SDA) pulled up but no signals, during the measurements i had a signal on the SCL in selfboot mode but not anymore.

Connecting the I2C to a Raspberry pi an doing a i2cdetect i get responce of the EEPROM but no response of the ADAU.

I checked the schematics but i cannot see a problem can anyone of you help me getting this started. What am i missing or doing wrong? what is the next to measure or test to be sure the ADAU is working or communicate with it? are there settings in sigma studio i need to make to connect to the ADAU?

I hope you can help me with my problem,

Regards,

Johan.

Audio Signal Processors

SigmaDSP Audio Processors

adau1701