no uart comunication

[Andrej152]

Hello, i working on project with arduino DUE and this ATM90E26 as AC voltmeter / ampmeter and i having a HUGE problem: i starting testing it with esp8266. i have galvanic isolation with super fast optocoupler. everythink is fine, after upload it send every second lot of bytes to rx pin of ATM. but i have no data from tx pin of chip. i tryed a lot of modifications like pulting SCK and CS to low and high and nothing. i want to test it with arduino due and it show a lot of error in code.. what can i do ?

thanks me lot.