The WAV Trigger gets 2 more voices and a low power Sleep Mode
I just posted a firmware update that adds 2 more voices for a grand total of 14 stereo voices. I think I’m getting close to what’s possible with this architecture. It’s a trade-off between microSD card access time, the amount of RAM available for buffering microSD card audio data and processor cycles. I might be able to get one more with a lot of effort, but I believe that 15 would likely be the theoretical limit.
This version also adds a low power “sleep” mode option. Adding the following line to the init file:
where N is seconds, will cause the WAV Trigger to enter a low power Sleep Mode after N seconds of inactivity. You’ll know it’s in Sleep Mode because it will blink 3 quick flashes and then “heartbeat” flash will stop completely. Any trigger activity will wake the WAV Trigger, the heartbeat will resume and it will immediately play a track if that trigger is assigned to do so. There is probably a small latency penalty paid by the trigger that does the waking, since the WAV Trigger has to restart the audio subsystem before it can play the track.
I still have to make measurements, but it’s safe to say at this point that in Sleep Mode mode, the WAV Trigger draws only about 5 milli-Amps. I’ll measure and post this spec on the product page along with the actual wake-up trigger latency.
Update: The latest version of the InitMaker (v1.04 app) now supports the #LPWR entry. Get it on the downloads page.