cost Development Board designed to use it with AVR Mega16 and Mega32
microcontrollers. It has connectors for parallel ports A, B, C and D and
connectors for ISP and I2C bus. It also has RS232 serial
interface, 5V voltage regulator, 8 LED and 8 switches for connection to any
port. It needs external power between 8V to 24V or 5V from USB connector. All
connectors have 5VDC and GND line. The switches can give either logic 0 with
pull up resistors or logic 1 through resistors, depending on the connection of
jumpers which are placed near the main connector. The microcontroller can use
its internal oscillator or external by mounting the desirable XTAL to a connector
close to microcontroller (the capacitors are already installed).
connected to switches and the resistor in RESET are 10kÙ. All resistors
connected to LEDs are 510Ù. All resistors
connected to port B are 240Ù (these are essential resistors in
order to avoid short-circuit with ISP if it is connected). The four electrolytic
capacitors connected to max232 are 1ìF/63V.
The two capacitors connected to XTAL are 22pF. The electrolytic capacitor
connected to 7805 is 100ìF/25V and the three capacitors
near the ports are 100nF.
The microcontroller can be programmed by the ISP Port using the USB In System Programmer described in Project section. Substitutionally
can be programmed through the serial port of Development Board by adapting, as
sawn in the pictures that presented, a simple programmer with a Tiny2313 (.hex
file). This programmer can be assembled in an experimental board.