Accelerometor Lab View examples - pin out matching - configuration

[mbone]

Hi All

My team ask me to look into using the Accelerometer to give feed back
for balancing robot.

First queston: I do not have any experience with this, is the accelerometr a good choice for this?
Will it be accurate enough? I am concerned about noise in the measurement,how do you handle if have
too much noise for accuracy?

I reviewed all of the LabVIew examples and found 4. IC2 and SPI are the first two. From what
I read, it appears there are two ways to communicate with board. What is the difference and/or
preferred way?  My team has wired up for SPI because they indicated it was easier to wire, they never
wired/used the IC2 connections on side car.

I will be starting with SPI (J4 wire connection). I found ADCL345 data sheet and tried to make some sense
of it, a lot of info. Figures for SPI in data sheet shows different signal names than what is
in Lab View example. SPI Example,can someone explain this more, uses for MOSI channels?

Other two example are alarm and angle.  Is the angle example the one used to accomplish Robot balance
feedback (ie... when angle at X +/- 2 degrees, robot will be balanced?)  The example shows X-5-G pins on
accelerometer board, but do not see those pins on board.

Tha Labview Angle example shows y-axis (Y-5-G) and X-Axis (X-5-G), I do not know
how to correlate that to the SPI wiring my team did with SPI example.

NOTE: I saw some threads that need to turn board on with instrcution code, but do not see in examples?

thank you
Mark

[sciencewhiz]

If you plan to use SPI, make sure to get the fixed version of the example: http://firstforge.wpi.edu/sf/go/artf1432

[DAQjr]

mbone wrote:

First queston: I do not have any experience with this, is the accelerometr a good choice for this?
Will it be accurate enough? I am concerned about noise in the measurement,how do you handle if have
too much noise for accuracy?

This is a fine application for the accelerometer.  Probably the most appropriate application in recent years.

mbone wrote:

I reviewed all of the LabVIew examples and found 4. IC2 and SPI are the first two. From what
I read, it appears there are two ways to communicate with board. What is the difference and/or
preferred way?  My team has wired up for SPI because they indicated it was easier to wire, they never
wired/used the IC2 connections on side car.

I will be starting with SPI (J4 wire connection). I found ADCL345 data sheet and tried to make some sense
of it, a lot of info. Figures for SPI in data sheet shows different signal names than what is
in Lab View example. SPI Example,can someone explain this more, uses for MOSI channels?

There are some LabVIEW examples that use the support the ADXL345 (only in the kits for the last few years... interface is I2C or SPI) as well as older accelerometers (these had an analog interface... this is what the accelerometer palette supports).

Since you are using the ADXL345 on SPI, you need to use the driver that is included in the ADXL SPI example.  MOSI is an acronym for "Master Out, Slave In"... it simply indicates which pin each device will transmit on.  You need all 4 pins wired in addition to power and ground.

mbone wrote:

Other two example are alarm and angle.  Is the angle example the one used to accomplish Robot balance
feedback (ie... when angle at X +/- 2 degrees, robot will be balanced?)  The example shows X-5-G pins on
accelerometer board, but do not see those pins on board.

Tha Labview Angle example shows y-axis (Y-5-G) and X-Axis (X-5-G), I do not know
how to correlate that to the SPI wiring my team did with SPI example.

You cannot use those examples since they rely on an analog accelerometer.

mbone wrote:

NOTE: I saw some threads that need to turn board on with instrcution code, but do not see in examples?

The driver in the example should be doing this for you.

-Joe