SPI Pressure sensor interfacing?

Forum 2005-2010 (read only) Hardware Interfacing
1

Hi!

I am currently looking at trying to interface a 3-wire SPI Pressure Sensor(http://www.intersema.ch/products/guide/calibrated/ms5541c/) to an Arduino. The interface is really a standard SPI, but with a very peculiar clock frequency(32.768 KHz) and without the CS/SS chip select function.
Now, i need some thoughts, feedback and just generally good ideas on how to interface this. Here are a few questions:

Can i use the Arduino SPI-library?

Will I have to manage all communications using SoftwareSerial?

In the datasheet, which can be found in the link above, specifies that the sensor chip and the microcontroller should both be connected to te crystal, which effectively means that they will be running at the same speed. Do I have to run the Arduino at 32.768 KHz or is there someway to use an external signal as the SPI clock signal?

2

Well I read the datasheet a little different. There are two clocks the device is using. MCLK is the system clock for the internal A/D and other internal circuitry and is spec'ed at 32,767 hz. The second clock signal is a digital input called SCLK which clocks in the serial SPI data and I see no reason that it must be run at 32khz only, so I think it would work fine with the standard Arduino SPI library. You will of course have to supply the 32khz mclk. At least that is my take on it, for what it's worth. :wink:

Lefty