I'm looking for some help with setting up a Labview VI to use SPI communication between an NI-8452 and a texas instruments ADS1278 A/D converter evaluation board. From all of the sample VI's I have seen the LabVIEW routines vary widely for different models of Texas Instruments ADC's. My issue is how to deal with the DRDY pin on the ADC; it is an active low output from the ADC and signals when valid data is ready for retreival.
There is a DRDY pin listed under the SPI stream configuration property node, but I am not sure how to set this up as it is a seperate pin from the standard SPI 4-wire communication (SCLK, MOSI, MISO, and CS). Also, this ADC does not use the chip select (CS) line. I would like to set the program up so that an interrupt is triggered when the DRDY pin pullls low and enters a standard SPI stream routine.
Any information on how to deal with this DRDY signal would be greatly appreciated.
I highly recommend saving the NI-845x Hardware and Software Manual if you are looking in using SPI communication with the 8452, as it is extremely helpful. We can see on page 387 (Chapter 14, section 4), there are descriptions for the extra SPI pins. The DRDY pin is configured as an input using GPIO1, so P0.1 for the 8451 and DIO1 for the 8452.
Also, I would recommend posting any future SPI communication or NI-845x questions to the Automotive and Embedded Networks forum. This way you'll get exposure to other users that are more familar with what your looking into.
Hope this helps!