hi,
i try to use the teensy audio board and an teensy3.6 as usb audio interface connected to an raspberry pi.
at least it is possible to process audio, but it periodically start crackle. dependen to my buffersice it need more or less time if crackle will start. i configured my pi with jackd to get an low latency guitar fx - pedal. my jackd call "jackd -P75 -p16 -t2000 -dalsa -dhw:1 -p128 -n3 -r44100 -s".
firstly i was thinking the problem is on my pi. many hours later now, and several test with commercial usb class compliant sondcards like the alesis io|2, which works perfect without any crackle or xruns down to 128 samples buffer at 3 periods -> around 2.9ms input output latency, i think the problem is caused from the teensy usb_sound mode. maybe it is similar to the mac osx crackle problem. i do not know because i have no mac. connected to my linux pc my teensy based usb sound card works perfect with jackd on -p128 -n3 (128 samples and 3 periods). but this will say nothing. the kernel modules for alsa (snd_usb_audio) are heavy modified to run on arm architecture. so an i386 linux snd_usb_audio module works smooth but an arm usb_snd_audio module produce crackle sound.
did anybody have similar problems or maybe get an teensy as audio interface working with an raspberry pi?
i use the new raspbian stretch light image as base for my audio raspberry pi(headless system).
/g
wolke
edit:
i use teensyduino 1.39 . the audio library i used is the latest head cloned from github repository.
i try to use the teensy audio board and an teensy3.6 as usb audio interface connected to an raspberry pi.
at least it is possible to process audio, but it periodically start crackle. dependen to my buffersice it need more or less time if crackle will start. i configured my pi with jackd to get an low latency guitar fx - pedal. my jackd call "jackd -P75 -p16 -t2000 -dalsa -dhw:1 -p128 -n3 -r44100 -s".
firstly i was thinking the problem is on my pi. many hours later now, and several test with commercial usb class compliant sondcards like the alesis io|2, which works perfect without any crackle or xruns down to 128 samples buffer at 3 periods -> around 2.9ms input output latency, i think the problem is caused from the teensy usb_sound mode. maybe it is similar to the mac osx crackle problem. i do not know because i have no mac. connected to my linux pc my teensy based usb sound card works perfect with jackd on -p128 -n3 (128 samples and 3 periods). but this will say nothing. the kernel modules for alsa (snd_usb_audio) are heavy modified to run on arm architecture. so an i386 linux snd_usb_audio module works smooth but an arm usb_snd_audio module produce crackle sound.
did anybody have similar problems or maybe get an teensy as audio interface working with an raspberry pi?
i use the new raspbian stretch light image as base for my audio raspberry pi(headless system).
/g
wolke
edit:
i use teensyduino 1.39 . the audio library i used is the latest head cloned from github repository.
Last edited: