User i/o & power outputs, Pushbuttons, Buzzer – Pololu Orangutan SVP User Manual
Page 9
For each motor, the Orangutan SVP has a current-sensing circuit that produces an output voltage proportional to
the current the motors are using (850 mV/A). The respective outputs of these circuits are labeled CS1 and CS2,
and they are accessible near the center of the board.
User I/O & Power Outputs
Sixteen user I/O lines can be accessed via the four 4×3 0.100" female headers along the lower edger of the board,
as shown below. Each I/O line has associated power and ground connections for easy connections to sensors: the
exterior (bottom) pin is ground, the middle pin is power, and the interior (top) pin is signal and connects directly
to an AVR I/O line.
For each four-pin bank of I/O lines, you can configure which power voltage is supplied to the power (middle)
pins. By default, the power pins are connected to VCC (5 V). You can cut a trace on the bottom of the board
to disconnect them from VCC. This will leave the power pins connected to one through-hole, which can be
connected to a different power source, such as VADJ, which is available elsewhere on the board.
The total current available on the VCC (5 V) line is 3 A, meaning you can power servos and other high-power
peripherals directly from your regulated voltage.
LCD
The Orangutan SVP is supplied with a removable 16×2 character LCD with backlight that uses the common
(109k pdf). A
different LCD can be connected with an appropriate cable. The AVR has four I/O lines connected to LCD data
lines DB4 – DB7 (i.e. is configured to use the LCD in 4-bit mode) and three I/O lines connected to the three LCD
control lines RS, R/W, and E. Please note that the LCD data lines are also shared by the user pushbuttons and the
green user LED. You can print to the LCD using the functions in the
section of the Pololu AVR C/C++ Library.
The LCD’s backlight can be turned off by driving the BACKLIGHT line low. Adjustable dimming of the LCD
can be achieved by connecting the line to a free PWM output.
The AVR’s AREF pin is available next to the backlight pin.
Pushbuttons
The Orangutan SVP has five total pushbuttons: a power on/off button located on the right side of the bottom
edge of the board, a reset button located on the left side of the top edge of the board, and three user pushbuttons
located along the left edge of the board. Please note that the power button disconnects the external power supply
from the entire board, while the reset button connects directly to the AVR’s RESET pin and does not disconnect
the power supply.
The user pushbuttons, from top to bottom, are on pins PC5, PC3, and PC2. Pressing one of these buttons pulls
the associated I/O pin to ground through a resistor. You can detect button pushes using the functions in the
section of the Pololu AVR C/C++ Library. The library
takes care of configuring the pins as inputs, enabling the AVR’s internal pull-up resistors, and debouncing
(accounting for the fact that pushbuttons physically bounce when pressed).
Buzzer
The Orangutan SVP comes with a buzzer controlled by pin PD4. If you alternate between driving the buzzer pin
high and low at a given frequency, the buzzer will produce sound at that frequency. You can use the functions in
the
section of the Pololu AVR C/C++ Library to play notes in
the background (using hardware PWM) while the rest of your processor performs other tasks.
Pololu Orangutan SVP User's Guide
© 2001–2012 Pololu Corporation
4. Module Pinout and Components
Page 9 of 37