How to configure the MMA68xxKW sensor to get the acceleration data(g-value) on any axis.

[sivadhanekula]

Dear all,

Recenlty I have started using MMA6813BKW dual axis SPI sensor. I need to calculate the g-value out of this sensor and I am trying to configure it as below.

• Vcc supplied with 3.3v
• VREG and VREGA are connected to center plate with 1uf cap, VSS is given to ground
• MOSI, MISO, CLK and CS are connected to SPI tool.

I have configured the sensor according to the details given in the data sheet page num: 45, sec: 4.1. I requested the raw acceleration data out from x-axis, unsigned and with odd parity. based on the above configuration I send the SPI MOSIcommand as 0x3004 (I send only this command 4times, no other configuration made) as a response MISO I am getting only 0x0E00, even if I move the sensor in all directions. Can you please support me on the following topics,

1. -Is the configuration I made correct? if not what I have to configure additionally.
2. -Is the single MOSI command enough to get the acceleration data?
3. -Do I additionally need anything other than the mentioned details to have acceleration data at least on one axis.

Thanks in advance.

Best Regards

[JamesScott]

Here is another thread which might give you some clues.

It talks about configuring the device.

community.freescale.com/thread/301952

MMA68xx initialization

Can you explain what the "center plate" you are refering to when you explain how you connected the reference pins?