Hello, Could someone explain me clearly how I can read simultaneously the four AD7764 24bits ADC following the scheme given by Analog Device? See what I want to do on pages 24-25 of the attached linked pdf. Best regards.

http://www.analog.com/static/imported-files/data_sheets/AD7764.pdf

(N.B I am really poor in programming)

Please,nobody to help me ?

Thanks.

This looks like an interesting (and complicated) interface. It would probably be best to start by implementing read/write communications for a single chip. Then move on to the cascaded chips.

If I read the spec correctly, you will need to swap master and slave roles on the mbed SPI port depending on whether you are writing or reading the AD7764.

The mbed should be the master when you are writing to the AD7764 (so an mbed DigitalOut pin should be used to strobe the AD7764's FSI/ pin).

When you are ready to receive data, try setting up the mbed as an SPI slave, and use the FSO/ signal to drive the mbed's SSEL pin.

To help you get started, you might take a look at this thread, which discusses a few issues with 32-bit SPI.

Good luck.

Thank you Hexley,

These are very good advices. I will try it but not before 3 to 4 weeks....I am overloaded at work.

Thank you a lot. Henri