Page 472 - Robot Builder's Bonanza

UNDER THE HOOD OF THE TYPICAL MICROCONTROLLER CHIP 441

Figure 35- 3 Three
typical microcontroller
form factors: bare
integrated circuit (chip-
only), carrier board, and
development board.

further experiments. Not all carriers are shaped like ICs. Some look more like long
sticks, with one or two rows of connection pins.
Integrated development board: Physically the largest of the bunch, integrated (all- in- one)
development boards contain the microcontroller and support electronics, plus extras
like LEDs, switches, and header connections for experimenting. Using jumper wires,
you can connect the development board to a solderless breadboard, where you might
attach sensors, servo motors, and other external components.

G Separate development boards are commonly available for chip- and carrier- style
microcontrollers. These offer the best of both worlds; you get a compact controller when you
must conserve space, but, when needed, you can transplant the MCU to the board.

Under the Hood of the Typical
Microcontroller Chip

A key feature of microcontrollers is that they combine a microprocessor with various inputs
and outputs (called I/O) that are needed to interface with the real world. For example, the
Atmel ATmega328 28- pin microcontroller (Figure 35- 4) sports the following features, many
of which are fairly standard among microcontrollers.

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