ADXL 345 Sparkfun-- I2c--LabVIEW--Arduino

[Nathan_B.]

Are you getting incorrect values when using my library?

That datasheet states that the value is expressed as 2's complement, not left justified.  This implies that it is outputting a I16, not a I12 which means no bit shifting or special conversion need be done.  Also, the values that I output are raw values and still need a conversion factor for converting it to an actual value in units of g's.

Also, since this thread is for the ADXL345, we should continue this discussion in the [newly created] LIFA LSM303DLM Support discussion.

[areallygoodnoob]

Hi Nathan !

A friend and I are currently working on a project with arduinos and adxl. We tried your VI for adxl345 using I2C and it worked like a charm ! Now we are hoping to make it work using SPI. You said you would eventually add SPI to your VI, how is it coming along ?

Thanks in advance for your reply.

[Nathan_B.]

I've not really worked with SPI and I don't have the sensor to test with so I can try to do it quickly but I can't guarantee anything.

[Anthony-001]

Hello.

I want to make a project through which to read data values of ​​accelerometer with labview (just like shown above) but instead ADXL 345 type accelerometer can I use MMA 8452Q?

Any help will be appreciated.

Thank you for your support!

[Nathan_B.]

You can use any accelerometer that you want that uses a supported communication protocol (I2C, SPI, Analog, etc.).  You will need to manually build the VIs to communicate with it though.

[Anthony-001]

Hello,

I have tried to MMA 8452 and I have not found the datasheet or dates for the I2C communication and in conclusion, I purchased ADXL345.

The following problem which I have is that,  I need a graphic display of vibration depending on displacement (speed x, y, and z). A display as I look at the end in the attached below. How can I start?

Thanks,

[Nathan_B.]

Your description doesn't really make sense. Are you measuring vibration, displacement or speed?

If you are trying to measure vibration, I don't think you will be able to get very good results with LIFA because LIFA is quite slow and will not be able to obtain data quick enough to analyze even moderately high frequencies.  What frequencies do you need to measure?

[Anthony-001]

I measure the vibration depending on its frequency. Meaning, I fix the accelerometer on a metal body (electric motor) and I want to see at what frequency and amplitude vibrates. Basically frequency range should be up to 1000 Hz.

If I can not send data pretty quickly by the Lifa Protocol I can register (aprox. 50 sec)? and then to show my graphic form?

Thanks,

[Nathan_B.]

Well, according to the Nyquist Theorem, you would have to be able to sample at at least 2000 Hz to even begin to achieve that.  This is not possible using I2C via LIFA.

Anthony-001 wrote:

If I can not send data pretty quickly by the Lifa Protocol I can register (aprox. 50 sec)? and then to show my graphic form?

What?

[hesam1987]

Hi

I am connecting two MMA8452Q accelerometer on a same Arduino. I am using sequence from labview and repreat the same process for second acceleromet with just different deviceaddress.

I am still getting data from frist accelerometer and no data from second one.

Do I need to make any changes in library?

PLEASE HELP.