Extra NXT Sensing Abilities (Cont. User Comparison)
The two sensors that the NXT has that the RCX doesn’t are sound (db and dba), and ultrasonic. The ultrasonic sensor allows for the use of it to sense walls, opening the touch sensor to another purpose, as well as avoiding possible robot damage by collisions. However, the ultrasonic sensor is the most unstable of the four NXT sensors because it can be interfered with by other NXT ultrasonic sensors in the vicinity or even possibly by bats. The sound sensor allows for it to be controlled by clapping and other noises (even by sounds we don’t hear). Those are the two sensors that the RCX can’t have due to it’s lower chip speeds that the NXT can and does have.