Trouble with analogic signal acquisition on the F2808 board

Altair Forum User

Submitted by cbonnet on Tue, 03/23/2010 - 20:39 

 

When i'm monitoring the analogic outputs of my F2808 board i get the values i'm sending from my GBF source. In the meantime, when i'm using the classic debug method consisting in putting all the diagram in a unique compound, and then compile it with the 'include vissim communication interface' option, and finally running it in another diagram using the DSP-interface : all the analogic inputs are giving the same values, whereas the 2 signals they get are different. I already read the documentation and tried modifying the settings of the ADC converter, but without success.

Please find attached to this request 2 screenshots that respectively show the hoped result, and the actual results i get with my signals.

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Altair Forum User

Submitted by Anders89 on Tue, 03/23/2010 - 22:19.

From the Spectrum Digital pdf: 'Connect ADCLO to AGND or ADCLO of target system for proper ADC operation.' This means that the GND pins put helpfully next to the ADCxx pins are useless unless you connect ADCLO to GND (jumper P9.18 to P9.19).
Note that the TI controlCARD ties ADCLO to GND.

But I have found your problem. In the ADC config dialog, you can set the order of physical channel sampling. In your case you were sampling ADCA0 in all 15 sample slots. Find attached your diagram with the channel sampling order restored to 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15

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