AD5686 problems with timing

Hello, I'm Nikolai Ehrhardt from Germany,

I got problems with the timing of the AD5686,

I'm giving a falling flank on the Sync line, then the ATmega168 starts to transmit the dataword via USART in MSPIM beginning with 0011 for LDAC independant commands. But the DAC does not receive or work with the data. The Outputs keep low.

Greets & Thanks

  • I got it now. In my eyes the timing diagramm is not true. the sync flank has to come before the cycle starts.

    Following code works, I saw more people having problems, that weren't solved:

       PORTC ^= (1<<PC3);

        //for (int i; i <= 5; i++) _delay_us(1);

        USART_Transmit_3byte (0b00110001, 0b10100001, 0b10000001); // this is a function that does 3 transmits in a                                                                                                     //row, nothing special.

        while ( !( UCSR0A & (1<<UDRE0)) );

        for (int i; i <= 35; i++) _delay_us(1);

        PORTC ^= (1<<PC3);

    I'm using ATmega168 with MSPIM a cycle of 8Mhz and a baud of 250000

  • 0
    •  Analog Employees 
    on Feb 11, 2015 1:22 AM

    I'm moving this to the Precision DAC community. Someone there should be able to answer your question.

  • 0
    •  Analog Employees 
    on Aug 2, 2018 2:54 PM
    This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

    Thank you,
    EZ Admin