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Original question:

SPI chip select between ADS1282 and DAC8563.

DAC081S101: DAC DAC081S101 driver testing

Sandesh Kenjana Ashok
Prodigy 20 points
Part Number: DAC081S101

I have a SOT-23 package of DAC081S101. 

I am connecting this to imx processor via SPI2 interface. SPI drivers are enabled in the processor. SPI loopback test is successful.

Connections are as described :

DAC081S101 pins imx Processor connection
Va  3.3V
GND GND
Din MOSI of imx
SCLK SPI clock of imx
SYNC GND

And finally the analog voltage will be measured from multimeter. 

I am unable to get the analog voltage corresponding to the digital value written via MOSI pin.  Is anything wrong in the test setup ?

Are there any available test case code which i can use to test ?  

Best Regards,

  • 0
    TI__Guru 53773 points

    Hi Sandesh,

    I am not aware of any test code base for this device.

    First, the SYNC pin should not be statically grounded.  The device requires a falling edge of SYNC to begin latching the SPI data.  

    Next, you should use an oscilloscope or logic analyzer to verify that your SPI formatting is correctly (ensuring the data is being set up and latched on the correct edge).

    Thanks,

    Paul

  • 0 in reply to Paul_Frost
    Prodigy 20 points

    Thank you Paul for your reply.

    However, i am not completely aware of this way of testing. Could you explain give some procedures or sample test codes which i can go through ?

    Best Regards

  • 0 in reply to Sandesh Kenjana Ashok
    TI__Guru 53773 points

    The most common problem when people are having difficulties communicating with a device is that SPI data is not formatted correctly.  The easiest way to confirm this is to evaluate the communication with a common lab oscilloscope.  

    It is critical that the DAC data is setup on the rising edge and the data latched on the falling edge.  In addition, you need a SYNC falling edge before the communication begins.