Arduino Lib for encoder of motor with ros. It work like a PDEC peripheal. just keep in mind that it is handler by interrupt and it cost in cpu time : for 1 motor at 10k rpm with 1 tick per revolutions it cost 66kcyc per seconde (10000/60*450cyc) (without speed control) and it can create latency about 10µs@48Mhz that could drop data on serial if serial interrupt happen to late.