TM4C123GH6PM: BOOSTXL-SENSHUB Verification

Hello Mohamed,

I am not clear about what you are asking... are you asking about how to know if the calculations are done correctly?

Hello Ralph,

yes , i'm asking about how to know if the calculations are done correctly ? and how to test the output from MPU to make sure that he works correctly?

Thanks.

Hello - both to poster & vendor's Ralph,

Poster initially asked, "

Mohamed Elahmady said:

How can i make sure that the output data from MPU9150 is correct?

Young staff here had a (completely) different take - believing that poster was (more properly) "Seeking to, 'Confirm the correctness' of his sensor-generated readings."

Two of the MPU9150's capabilities may be 'Tested/Confirmed' via (reasonably) simple means.    These are the 3 Axis Accelerometer & Compass.   

Follows a very simplified/brief outline of such, "Confirmation of the MPU9150's output data" - just as poster requested:

• by commanding each accelerometer axis into their lowest range (±2g) it should be fairly easy to, "Orient the sensor so that the downward pull of gravity achieves ±1g of acceleration."    This method may be repeated 3 times - covering all 3 axes.
• similar method may serve to test the compass - and the introduction of a 'known output, miniature Neo Magnet' provides excellent compass-mode output monitoring.

It is suspected that the, "Mastery of the many Registers w/in the MPU9150" - and their "Correct set-up & interrogation" - will also be nicely 'Exercised & Tested' through this procedure.

There may exist 'technical hand-offs' between the (raw) MPU9150's outputs & vendor's (enabling/easing) software.    Again - the implementation of such, "Key, Known, Disciplined, MPU9150 Device Orientations" - in concert w/well constructed MPU9150 measurements - should add confidence to the 'Multi-Board System's results - as a whole!'

It should be noted that MPU9150 has been listed as 'EOL' - the usage/testing suggestions herein (thankfully) have escaped such 'death knoll.'

thanks for your time .

hello Ralph,

can you please give me the link to the library.

thanks.

Hello Ralph,

I just want to verify the results, just like comparing it with the true results.

I'm asking how to verify the results to make sure that my software project is completely correct ?

thanks a lot. 

Hello again,

If my group may (as it appears our earlier guidance was not (fully) understood) suggest that attention must focus upon 'your' definition of "Results!"

Kindly note the following aspects - which when integrated (taken together - as a coordinated group) yield "System Results."     (it is believed that 'System Results' is what you, "Should be seeking.")

Elements which go into your "System Results:"

• Sensor's Output Signals - "Do they properly reflect the parameters which are 'Input to the Sensor?'"
• Assumed Sensor Signal Handling by this vendor's specific API.   "My group has no knowledge of the full role of the vendor's API in this sensor regard."
• The user's handling & presentation of the results produced by the vendor's API.   "These may have to be modified based upon the uniqueness of user requirements - and/or the addition of (other) features/functions."

Now you've asked,

Mohamed Elahmady said:

I'm asking how to verify the results to make sure that my software project is completely correct ?

My small group frequently employs advanced sensors - of many types (often w/in the motion-control sphere) - and 'Correctness' demands the systematic approach (and verification of each step) - listed herein...     Note that the vendor (any vendor) has "No Control" over your operation of the sensor(s) - and thus a "Guarantee of complete correctness" - minus (much) further 'user' detail - is unlikely...

When "Chasing Correctness" - it proves 'normal/customary' that:

• Calibrated Input Conditions & Accommodations (often via highly specialized equipment) are presented to (each desired) sensor - ideally exercising all needed parameters.
• The sensor(s)' raw output is then analyzed to determine general "Sensor Accuracy."
• An MCU (somewhere) in this chain may then "Massage, Scale, or otherwise Process" the sensor(s) output - this stage may enable "sensor tweaks and/or calibration updates."

As should be evident - "Many variables are in play - and much investigation is demanded - when (REAL) correctness is sought..."    Even "Perfect Software" - minus the proper, "Choice, Implementation, & Integration" of the various "System Components" - cannot insure that the, "System performs to specification!"     And it is the System - not a single element - which must be optimized to insure 'correctness!'

Hello Mohamed,

The library is part of our TivaWare package: http://www.ti.com/tool/sw-tm4c

The sensorlib folder has all the library files.

There is a full example project at: [Install Path]\TivaWare_C_Series-2.1.4.178\examples\boards\ek-tm4c123gxl-boostxl-senshub\compdcm_mpu9150