89
Notes:
1) The sound signal received by the sound sensor used in this function design will output a high electrical level if the signal
does not reach the set threshold of the sensor, and a low level if the threshold is exceeded, but the situation for different types
of sound sensors varies.
2) Output levels by infrared obstacle avoidance sensors and touch sensors are only classified as high or low, therefore, the robot
can obtain functional area acquisition through the I/O port of the adaptor module that detects high and low electrical levels.