In order to avoid serial/USB or Ethernet connections and have a fast and steady datarate for my analog sensors, I was thinking about a way to connect them through the line inputs of my soundcard. As those are AC-coupled, I figured out this would be possible using a modulation/demodulation system: the sensor signal would modulate a high-frequency sine wave to go through the AC coupling. Then using a software demodulation (filter ?) I would get my low-frequency signal again.
- Which type of modulation would be easier to implement both on the harware (modulation) and software (demodulation) sides : amplitude ? Frequency ? PWM ?
- Which one would provibe best results (as for the S/N ratio and cleanliness of the final signal) ?
- Do I need an Arduino with "true" (non-PWM) analog outputs such as the Due or the Teensy to produce the analog signals resuting from such modulation ?
Thank you in advance.