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ADC output and Reference Sinewave in TMS320LF2407A processor

Started by tsel...@gmail.com May 8, 2006
Hi all,

I am doing a project of DSP based on-line UPS(Inverter stage) using
TMS320LF2407 processor with C language. I have done this in open loop. Now
i am trying in closed loop. In this closed loop, the reference sine wave
and ADC output will be compared. I have generated the reference sinewave
in code composer studio using C program. I have given 2.56V via
transformer to ADC. I have seen the ADC output in DAC. The DAC output is
pure sine wave. If i compare these two wave forms (reference sine wave and
ADC output), I didnt get the proper sine wave output. I think these two
waveforms are not synchronized. Please suggest me how to synchronize the
ADC output (real time) and reference sine wave (non real time) using C?

Thanks & Regards
Tamilselvi.P



hi,

i guess that it can be done by starting your reference sine wave generation in the c program when ever the adc reads the max value on its lines as input.

if u know the amplitude of the input wave that u r giving,
then start the reference generation when the ADC input is greater or equal to (say) 2.56V (if amplitude is 2.56) or hex equivalent.

and start the ref generation with the starting point as the highest value(say sin 90)

by doing this u will start at a reference point common to both the waves

hope this works

there is another group for c28 series to which 24 series is closer so it can be of help to every one if u can join that group also and share ur experiences

the group is c...

bye

t...@gmail.com wrote:
Hi all,

I am doing a project of DSP based on-line UPS(Inverter stage) using
TMS320LF2407 processor with C language. I have done this in open loop. Now
i am trying in closed loop. In this closed loop, the reference sine wave
and ADC output will be compared. I have generated the reference sinewave
in code composer studio using C program. I have given 2.56V via
transformer to ADC. I have seen the ADC output in DAC. The DAC output is
pure sine wave. If i compare these two wave forms (reference sine wave and
ADC output), I didnt get the proper sine wave output. I think these two
waveforms are not synchronized. Please suggest me how to synchronize the
ADC output (real time) and reference sine wave (non real time) using C?

Thanks & Regards
Tamilselvi.P
I do not fully understand what your problem is. But if you need to sync the
reference to the real waveform (mesured) You can do it with zero cross (or
peeak as Jagadish said) detection.

Later, Janko
----- Original Message -----
From: "chirag jagadish"
To:
Sent: Monday, May 08, 2006 8:28 PM
Subject: Re: [code-comp] ADC output and Reference Sinewave in TMS320LF2407A
processor
> hi,
>
> i guess that it can be done by starting your reference sine wave
> generation in the c program when ever the adc reads the max value on its
> lines as input.
>
> if u know the amplitude of the input wave that u r giving,
> then start the reference generation when the ADC input is greater or
> equal to (say) 2.56V (if amplitude is 2.56) or hex equivalent.
>
> and start the ref generation with the starting point as the highest
> value(say sin 90)
>
> by doing this u will start at a reference point common to both the waves
>
> hope this works
>
> there is another group for c28 series to which 24 series is closer so it
> can be of help to every one if u can join that group also and share ur
> experiences
>
> the group is c...
>
> bye
>
> t...@gmail.com wrote:
> Hi all,
>
> I am doing a project of DSP based on-line UPS(Inverter stage) using
> TMS320LF2407 processor with C language. I have done this in open loop. Now
> i am trying in closed loop. In this closed loop, the reference sine wave
> and ADC output will be compared. I have generated the reference sinewave
> in code composer studio using C program. I have given 2.56V via
> transformer to ADC. I have seen the ADC output in DAC. The DAC output is
> pure sine wave. If i compare these two wave forms (reference sine wave and
> ADC output), I didnt get the proper sine wave output. I think these two
> waveforms are not synchronized. Please suggest me how to synchronize the
> ADC output (real time) and reference sine wave (non real time) using C?
>
> Thanks & Regards
> Tamilselvi.P
>