The best way to check your captured sine wave is to use a spectrum analysed program to view the data having first captured your data to a file, preferably in a recognisable format.
A while back I needed to read a WAV file of audio into a program. Turned out relatively easy to find detail on the WAV file header, read and adjust to it. Would be simple to cobble your own header and stick it on the front of your data capture to make a generally useful ADC checker.
Edit: just found this ref: http://soundfile.sapp.org/doc/WaveFormat/
If you are making a general purpose ADC input consider including a low pass /anti-aliasing filter between your audio source and ADC. A spectrum analyser will easily demonstrate the need for one.
If your sample rate is jittery then your sine wave will be FM modulated.
Any errors will show up as frequency artefacts
A while back I needed to read a WAV file of audio into a program. Turned out relatively easy to find detail on the WAV file header, read and adjust to it. Would be simple to cobble your own header and stick it on the front of your data capture to make a generally useful ADC checker.
Edit: just found this ref: http://soundfile.sapp.org/doc/WaveFormat/
If you are making a general purpose ADC input consider including a low pass /anti-aliasing filter between your audio source and ADC. A spectrum analyser will easily demonstrate the need for one.
If your sample rate is jittery then your sine wave will be FM modulated.
Any errors will show up as frequency artefacts
Statistics: Posted by RaspISteve — Fri Jul 26, 2024 2:50 pm