Thinklabs UNIBOARD V1.1, User Manual

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Setting up the Board configuration
Board Description
Atmega128 controller
The ATmega128 is a low-power 8-bit microcontroller based on the AVR enhanced RISC architecture. The
Atmel ATmega128 is a powerful microcontroller that provides a highly flexible and cost effective solution to
many embedded control applications.
Atmega8 controller with the firmware for programming through USB
USBasp is a USB in-circuit programmer for Atmel AVR controllers. It simply consists of an ATMega8 and a
couple of passive components. The programmer uses a firmware (USB driver) to program Atmega128
microcontroller. For more information on building USBasp refer http://www.fischl.de/usbasp . It is an open
source firmware along with hardware licensed under GNU GPLv2.
I2C and RTC (DS1307) with Backup Battery
The DS1307 serial real-time clock (RTC) is a low-power, full binary-coded decimal (BCD) clock/calendar plus
56 bytes of NV SRAM. Address and data are transferred serially through an I2C, bidirectional bus. The
clock/calendar provides seconds, minutes, hours, day, date, month, and year information (Compensation
Valid up to 2100). No special hardware configuration is required as it is mounted on our board and internally
connected to the processors pins.
Analog sensors (Joystick and LDR)
The Joystick (Analog joystick used in PS2 consoles) is connected to the ADC, X axis on channel 1 (PF1) and Y
axis on channel 2 (PF2) of the Atmega128 microcontroller. The LDR sensor is connected to channel 0(PF0) of
the Atmega128 microcontroller.
Buzzer
The Buzzer is connected to PA3 of the Atmega128 microcontroller, and lies beneath the processor board.
Onboard Motor Driver
The Motor driver chip (L293D) is used to drive the motors which can be connected to the PTR connectors as
shown in the above figure. Through software you need to configure as follows:
PB6 and PB5 (MOTOR1)
PE2 and PE3 (MOTOR2)
PB4 (CHIP ENABLE)
There are motors which might need higher than 5V (up to 12V) operating voltage. In such cases an external
supply can be given to the board and the USB power switch can be toggled to make the external supply
available instead of a USB powered connection.