Digilent Nanocon - Manual (Page 2)

Digilent, Inc. Nanocon Reference Manual
www.digilentinc.com
www.digilentinc.com page 2 of 6
Copyright Digilent, Inc. All rights reserved. Other product and company names mentioned may be trademarks of their respective owners.
Features of the ATmega168 include:
• master/slave serial peripheral
interface (SPI)
• programmable serial USART
interface
• Atmel two wire serial interface (TWI)
• eight channel, 10-bit ADC
• two 8-bit timer/counters
• one 16-bit timer/counter
• 16KB program flash
• 512 byte EEPROM
• 1KB internal SRAM
• analog comparator.
For more information on the ATmega168
microcontroller, refer to the data sheet
available at
www.atmel.com .
Functional Description
The Nanocon is designed for embedded
control and robotic applications as well as
microprocessor experimentation.
Embedded firmware, suitable for many
applications, can be programmed into the
Nanocon’s ATmega168 microcontroller.
Although the Nanocon can be used as a
stand-alone microcontroller board, it is also
designed to be part of a larger system
using a distributed processing architecture.
Connector J1 allows the Nanocon to be
plugged directly into other Digilent
microcontroller boards, such as the
Cerebot™ or the Minicon™. Using a 6-wire
cable and the Digilent Module Interface
Board, it can be connected to a Digilent
FPGA board.
The Nanocon can be programmed with
firmware to perform local control functions.
It can then be controlled by, and report
back to, a higher level controller in the host
controller board. For example, the
Nanocon could be programmed to perform
closed-loop motor speed control. It could
relieve extra work for the host processor,
when performing the motor speed control,
by processing commands from the host
and controlling the motors itself.
Communication Options
Connector J1 provides access to the
master/slave SPI. SPI is a high-speed,
synchronous, serial interface used by
many serial peripheral devices like A/D and
D/A converters. The SPI interface is used
both for in-system-programming the
ATmega168 and for a user-accessible SPI
port. The Digilent PmodAD1 and
PmodDA1 modules use the SPI interface.
Connector J1 and the SPI interface are
also used for in-system-programming of
the ATmega168 microcontroller.
Connectors JA and J2 provide access to
the Atmel two-wire interface (TWI). The
TWI is a medium speed (200-400 Kbps)
serial bus that allows up to 128 devices to
connect. Connector J2 can be used for
continuing the TWI bus to other boards.
The ATmega168 microcontroller provides a
USART that can be used for asynchronous or
synchronous serial communications. However,
the Nanocon doesn’t provide for a crystal
oscillator, and the internal RC oscillator isn’t
accurate enough for reliable asynchronous
communications. It is sometimes possible to
tune the oscillator using the calibration register
to allow asynchronous communications to
work.
6-Pin Pmod Headers
The Nanocon has four 6-pin header
connectors for connecting to general-
purpose, off-board digital I/O or to specific
ATmega168 features like analog-to-digital