[chuck-users] Set adc sampling rate

Hi guys! I'm trying to make some analysis of the micro input and to do so I have to take my micro input with a sampling rate of 8000 Hz. I've checked my micro supports that (with chuck --probe) but in the doc I haven't found how to set the sampling rate of adc. Does someone know how to do that? Or does someone know where I can find some kind of API doc where everything is listed? In the ChucK language specification or in the Unit Generators Reference I cannot find much info about it. Thanks!Guille