Atmel’s itty-bit­ty ATtiny85 8‑Bit Proces­sor. 8K of pro­gram space, 6 I/O lines, and 4‑channel 10 bit ADC. Runs up to 20MHz with exter­nal crys­tal. Pack­age can be pro­grammed in cir­cuit.DOCUMENTSProd­uct CardArduino Board Def­i­n­i­tions