Page 176 - Robots Androids and Animatrons : 12 Incredible Projects You Can Build

7.7 Speech-controlled R/C car

New board features
The voice-controlled mobile robotic platform is shown in Fig. 7.7.
The circuit board on the robot looks a little different than that in 155
Fig. 7.4. The reason for this is that I happened to get a prototype
of the latest revision of the speech kit.
The latest revision makes interfacing to the SRC easy. There are
nine PC holes [for a pin header (two 4-bit nibbles plus ground)]
that connect to the output of the onboard 74LS373. The output of
the onboard 74LS373 is the upper BCD used for word-error detec-
tion and the lower BCD used to activate the 4028. A trigger signal
is available by the red LED.
In addition to the interface hookups, the board has a 3V input for
memory backup. This makes the static RAM on the speech board
nonvolatile. So you can turn the board on and off without losing
the words programmed in the static RAM. In the original version,
when you turned off the power, you lost the words programmed in
the RAM.

Project 3: General speech-recognition interfacing circuit

The speech interface to the mobile R/C car is a specialized appli-
cation. The next interface circuit (see Fig. 7.8) is a more general
circuit and lends itself to controlling a variety of devices that in-
clude robots, electric circuits, and appliances.
Team LRN Speech-controlled mobile robot