How to configure the MMAxxKW 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 MOSI

command 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

[Pascal_BERNARD]

Hi,

Information (hardware and source code) is available at Automotive Sensors Tower System Module Freescale (http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=TWR-SENSOR-PAK-AUTO&tid=m32TWR).

Refer driver for MMA6800 or MMA6500.

Many Thanks,

Pascal

[reyes]

Hi Siva Dhanekula,

Please take a look at the Scott James Answer in the following thread: How to configure the MMA68xxKW sensor to get the acceleration data(g-value) on any axis.

Regards,

Jose

[Wlodek_D_]

Dear Siva Dhanekula,

Thank you for your post, however please consider moving it to the right community place (e.g. Sensors) for better visibility.

For details please see general advice https://community.freescale.com/docs/DOC-99909

Thank you for using Freescale Community.

Regards,

Wlodek_D.