SRS Labs SRS Robot Level 1 Kit manual AVR Robot Controller 1.1 Hardware Description, Power, Pins

AVR Robot Controller 1.1 Hardware Description

AVR Robot Controller 1.1 Hardware Description

The Level 1 Robot Kit ships with an ATmega16 microcontroller. The Atmel AVR microcontrollers are designed to be pin- and code-compatible where possible. In this case, for example, you could substitute an ATmega8535 or ATmega32. These chips will all function in the ARC board with minimal software changes (typically just a re- compile), the primary difference being the amount of internal memory available. Please see Atmel’s site (www.atmel.com) for a list and descriptions of available devices.

Power

Power can be any source from 6-24 volts DC. Pay attention to the polarity symbols near the power plug -- ground is in the center, with +V applied at either end. The ARC board is protected against battery reversal with a diode. This diode reduces the available power to the board and prevents destruction of the H-Bridge in case of accidental battery reversal. If you want, you can use a polarized battery connector and solder it directly to the board and replace the diode with a bare wire.

I/O Pins

The ATmega16 microcontroller has four 8-bit I/O ports and many peripheral functions that work through these I/O pins. Port A also doubles as the analog input port. Port D doubles for many of the built in functions like serial I/O, PWM and timers. Port B doubles as the programming interface.

The following table lists the I/O pins that are brought out to headers on the ARC board. (The expansion headers JP3 and JP10 are not included since they bring out all I/O port bits as well as power and ground.) Connection lists what device or feature the robot communicates with. Physical Pin is the connection to the ATmega16. Functional Name indicates how each connection is used in the programs. Input/Output describes the communication direction as viewed from the ATmega16. Header is the text identifying that connection on the board. (See the schematic for pin details.)

	Physical	Functional	Input/
Connection	Pin	Name	Output	Header
Left bump sensor	PA0	PA0	input	LEFT (at front of board)
Right bump sensor	PA7	PA7	input	LEFT (at front of board)
Left distance sensor (Level 2)	PA0	ADC0	input	RIGHT (at front of board)
Right distance sensor (Level 2)	PA7	ADC7	input	RIGHT (at front of board)
Left light sensor	PA1	ADC1	input	LF (“left floor”)
Center light sensor (not included with kit)	PA2	ADC2	input	CF (“center floor”)
Right light sensor	PA3	ADC3	input	RF (“right floor”)
Left motor direction	PC3	PC3	output	LEFT (at back of board)
Left motor PWM	PD4	OC1B	output	LEFT (at back of board)
Left motor channel A (encoder, Level 3)	PD3	INT1	input	LEFT (at back of board)
Left motor channel B (encoder, Level 3)	PC2	PC2	input	LEFT (at back of board)
Left servo (not included with kit)	PC2	PC2	output	LEFT (at back of board)
Right motor direction	PC4	PC4	output	RIGHT (at back of board)
Right motor PWM	PD5	OC1A	output	RIGHT (at back of board)
Right motor channel A (encoder, Level 3)	PD2	INT0	input	RIGHT (at back of board)
Right motor channel B (encoder, Level 3)	PC5	PC5	input	RIGHT (at back of board)
Right servo (not included with kit)	PC5	PC5	output	RIGHT (at back of board)
Serial input	PD0	RXD	input	JP5
Serial output	PD1	TXD	output	JP5
Green “program” LED	PB4	PB4	output	PROG (green LED)
Option A	PB6	PB6		ISP/JP9, A
Option B	PB7	PB7		ISP/JP9, B
Option C	PB4	PB4		ISP/JP9, C

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