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Using SPI to write to AD5668

Topic last updated 30 Apr 2010, by tim owen. 1 reply
Eugenio Culurciello
29 Apr 2010

Hello,

I have been trying to interface the 16-bit AD5668 DAC using SPI.  However, the AD5668 has a 32-bit input shift register while the SPI can only support 16-bits per frame.  Thus, how do you get the required 32-bits for instruction to the DAC?  Use spi.write() twice?

tim owen
30 Apr 2010

Hi,  I think the AD5668 will not notice the difference between  1x32 or 2 x 16 if you keep your CS line asserted between the frames.  The MBED spi CS is not handles automatically so you have control.  At least that is how I read it.