serial port, which provides a two-way communication at 5~V~\acs{TTL} levels over
a 7-pin mini-\acs{DIN} connector, with a speed of either 19,200 or 115,200 Baud,
in mode \acused{8N1} \ac{8N1} (\acl{8N1}). Over this serial port, the Roomba
-speaks a specified protocol, called the \acused{ROI}\definition{\acl{ROI}}
-(\acs{ROI})~\cite{irobot-oi}, which allows the user to interact with the robot's
-internal logic, reading its sensor values, and control its movements and
-cleaning behaviour.
+speaks a specified protocol, called the \acused{ROI}\definition{Roomba Open
+Interface} (\acs{ROI})~\cite{irobot-oi}, which allows the user to interact with
+the robot's internal logic, reading its sensor values, and control its movements
+and cleaning behaviour.
After starting the communication with the Roomba by sending the \cmd{Start}
command, the robot is in a state called \definition{Passive mode}. In this mode,