@Makerfabs sent me 2 PCBA Sample last week, so i could work for the firmware this weekend. After upload the fw i just surprise the sound and button didn't works, i spent two hours to see what happened. I didn't make any changes on button, then after reads the datasheet there's different i2c address scheme between PCF8574AT and PCF8574T. Earlier prototype PCF8574AT was used ( salvaged from 1602 lcd i2c backpack ) and the address 0x38 was used, with this sample PCF8574T the address is 0x20, one problem solved.

The Sound is different case, after 3 hours struggled with the programming the problem is not the software but really bad typos on schematics, the resistor for R-C filter was wrongly typed from 1 Ohm to 1 KOhm, swap the resistor with the right one and VOILA the sound works. The Sound output are really clean on the headphone and very low noise output from the speaker, really satisfied with the result.