I have not done any real DSP stuff apart from doing some spreadsheet simulations with all sorts of filters and their coefficients.
I now have a possible application for a small dsp.
The input to the chip will be a full wave rectified sinewave (positive going half sines).
The frequency is ~50 Hz (100 if counting the half sines).
These need to be samples with A/D at a rate of at least 5k samples per second.
I then need to low pass filter each half sine but I really need to preserve the sharp edges at the bottom where they join.
In addtion, I need either 0 or 180 or 360 degree phase shift.
Does this sound like a plasible application for a small dsp?
How can I go about implementing / evaluating something like this?
You better describe what you actually want to achieve.
After low-pass filtering the rectified sine you either get a pure DC voltage, or a DC voltage with superimposed 100 Hz sine, or some 100 Hz harmonics in addition, depending on the filter characteristic.
In any case, the filter will cause a group delay respectively phase shift and in no way "preserve the sharp edges" of the rectified waveform.
You better describe what you actually want to achieve.
After low-pass filtering the rectified sine you either get a pure DC voltage, or a DC voltage with superimposed 100 Hz sine, or some 100 Hz harmonics in addition, depending on the filter characteristic.
In any case, the filter will cause a group delay respectively phase shift and in no way "preserve the sharp edges" of the rectified waveform.
You didn't tell much about the application, so I can only guess about the exact requirements. I understand that you want the phase rather exact, which is essentially a digital information (zero crossing pulses). The 50 Hz magnitude is an analog information, but the required accuracy hasn't been told yet.
You didn't tell much about the application, so I can only guess about the exact requirements. I understand that you want the phase rather exact, which is essentially a digital information (zero crossing pulses). The 50 Hz magnitude is an analog information, but the required accuracy hasn't been told yet.