SPI communication between ARM MCU and ADC

[Hemadri]

We are facing some problem with reading data from AD7738:

The required configuration of AD7738 is:
1.) Continuous Conversion Mode.
2.) Conversion time 88h (Chopping enabled mode).
3.) Differential Channel with +/-2.5V.
4.) Dump Mode.
5.) Clamp Bit Enabled.
6.) 24 bit.

We have configured AD7738 in the following sequence with the respective Command Word:

The writing sequence is as following:

1.) Writing to Communication Register:     01h (I/O Register Address)
2.) Writing IO Port Data:            20h
3.) Writing to Communication Register:    28h (Channel Setup Register Address)
4.) Writing Channel Setup Register:    6Ch
5.) Writing to Communication Register:    30h (Conversion Time Register Address)
6.) Writing Conversion Time Register:    88h
7.) Writing to Communication Register:    38h (Mode Register Address)
8.) Writing Mode Register:        2Fh
9.) Writing Continuous Conversion
    to Communication Register:        48h

The problem that we are facing are:
1.) The ready signal is always pulled high and it is never going low.

Can you suggest any solution to us.

[etki]

Could you provide a small example how to use multiple SPI-slaves with CS-lines on different GPIOs on the LM3S8962 eval board?

Can I use meanwhile also File I/O to write the data I gather from the SPI devices to a file on the SD-Card on the board ?

[GoCougs]

I threw something together that might be what you are looking for. Essentially you just need to wire in the specific ID for the chip that you are wanting to communicate with. Attached is an example of what you might be looking for. **NOTE: THIS HAS NOT BEEN TESTED TO WORK AND IS ONLY FOR AN EXAMPLE SET UP** I hope this helps!

Scott W