Mark & Celari
Mark
Hey Celari, have you ever tried mapping heart rate or breathing patterns to a low‑latency synth patch—like using a simple Arduino or Raspberry Pi to feed the bio‑signals directly into a VST? I’m curious how you keep the feedback loop tight enough to stay in the moment without the system getting bogged down.
Celari
Yeah, I’ve tried it a few times. I usually run the Arduino or Raspberry Pi on a low‑latency thread, pull the ECG or respiration every 50 ms, and feed it straight into a Max/MSP patch that drives a VST. The trick is to keep the buffer tiny—just a few samples—and let the synth handle the smoothing, so the brain feels the change almost instantly. If the system starts lagging, I hit a quick reset or drop the sampling rate a notch and the loop feels normal again. The whole point is to make the audio feel like your own pulse, so the feedback stays tight and you stay in the moment.
Mark
Nice setup, Celari. I usually stick to a fixed 40‑ms window and let the synth do a quick exponential smoothing on the incoming stream—keeps the CPU happy and the vibe real. If the reset thing works for you, it’s probably the only way to get the brain back into sync. Have you thought about using a light‑weight DSP library on the Pi to offload the filtering? Keeps the loop tighter without pulling the whole thread.
Celari
That sounds slick—using a DSP library would let the Pi juggle the filtering and still leave the audio thread light. I’ve dabbled with a tiny C++ filter, but I keep going back to Max for the tweak‑ability. Maybe try a tiny ring‑buffer on the Pi, feed the raw data in, let the synth smooth it out. Keeps the loop tight and the vibes real. Good idea!
Mark
Sounds like a solid plan. Keep that ring buffer lean, drop the smoothing to the synth, and you’ll have a clean, responsive pulse—no extra CPU drama. Good luck, and let me know if the Pi starts doing more than just buffering.
Celari
Thanks! I’ll keep the ring buffer tight and let the synth do the smoothing. If the Pi starts spouting its own music, I’ll let you know—might become a duet!
Mark
Nice, looking forward to the duet. Just make sure the Pi doesn’t try to play a whole track and expect a solo—keep it simple, keep it tight. Good luck!