Digilent 6032-410-000P User Manual

OOrrbbiitt BBoooosstteerrPPaacckk™™ RReeffeerreennccee

MMaannuuaal

l

Revision: June 5, 2013
Note: This document applies to REV A of the board.

Overview

The Digilent Orbit BoosterPack™ is an
add-on board for the Texas Instruments
Stellaris® LaunchPad microcontroller
evaluation kit. The Orbit greatly expands
the input/output capabilities of the
LaunchPad, as well as introducing Digilent
Pmod™ expansion connectors.

Features Include:

• two 1x6 Digilent Pmod™
connectors

• 3-axis accelerometer

• 256 Kbit I2C EEPROM

• I2C temperature sensor

• 128x32 pixel OLED display

• analog potentiometer

Orbit BoosterPack Hardware
Description

Introduction

The following gives a basic description of the
input/output hardware contained in the Orbit
BoosterPack and how to use it. Refer to
Appendix A for a table showing pin definitions.

OLED Graphic Display

The Orbit board provides a 128x32 pixel,
organic LED (OLED), graphic display panel.
The graphic display panel used is the
WiseChip/Univision UG-23832HSWEG04. This
display uses the Soloman Systech SSD1306
display controller.

The UG2832 has a power on/power off
sequence that should be followed. Failure to
follow the power on/power off sequence can
shorten the life of the display. The Orbit
provides two FETs for software control of the
two power supplies for the display. The

1300 NE Henley Court, Suite 3

Pullman, WA 99163

[phone] Voice | [phone] Fax

VDD_OLED control is used to turn on/off the
power to the logic of the display. The
VBAT_OLED control is used to turn on/off
power to the OLED display itself. These two
pins have pull-up resistors to turn off their
respective power supplies when not being
driven. The pins are made to be outputs and
are driven low to turn on the power supplies.

Power on sequence:

Apply power to VDD
Send Display Off command
Initialize display to desired operating mode
Clear screen
Apply power to VBAT
Delay 100ms
Send Display On command

Power off sequence:

Send Display Off command
Power off VBAT
Delay 100ms
Power off VDD

The display has a D/C pin (display or
command select) that is used to determine
whether bytes sent to the display are
interpreted as commands or as display data.
The D/C pin is driven high for display buffer
access and is driven low for command access.
This pin is shared with VBUS detection on the
LaunchPad. If VBUS is present, the pull-down
resistor acts as a pull-up resistor in conjunction

Doc: 6032-502-000 page 1 of 4

Copyright Digilent, Inc. All rights reserved. Other product and company names mentioned may be trademarks of their respective owners.

Orbit BoosterPack Reference Manual

with resistor 6 (R6) on the LaunchPad. Please
see the note in the Orbit BoosterPack
Schematic available from www.digilentinc.com.

The D/C pin is also a non-maskable interrupt
(NMI) pin on the LaunchPad, and is “locked”
on the device’s power-up. In order to unlock
the D/C pin to be used as a general purpose
output, 0x4C4F434B must be written to
GPIOLOCK register. For more information,
please see the LM4F120H5QR Datasheet at:

www.ti.com.

The RES pin is used to reset the SG1306
display controller. The RES pin is driven low
for reset and driven high for normal operation.
The low-going reset pulse must be a minimum
of 3µs (microseconds) for the display controller
to reset correctly.

The UG2832 is a serial device that is accessed
using SPI. It is however, a write-only device. It
is not possible to read back either the display
buffer contents or any kind of status from the
panel. The maximum SPI clock frequency
supported by the UG2832 is 10MHz.

Digilent has a library for use with the Orbit
BoosterPack that provides functions for
initializing the display and rendering simple text
and graphics onto the display. This library can
be used as is or as a starting point for a more
sophisticated graphics library and is available
at www.digilentinc.com.

Digilent Pmod™ Connectors

Two 1x6 pin female Digilent Pmod connectors
are provided for functional expansion of the
Orbit BoosterPack. They are labeled JA and
JB respectively. Header JA has signals routed
to the Synchronous Serial Interface (SSI)
peripheral on the LaunchPad. These signals
can be used with Pmods that use standard 3 or
4 wire SPI communication protocol.

Discrete Digital I/O Devices

Pushbuttons: There are two pushbutton

switches labeled BTN1 and BTN2. A read to

the corresponding GPIODATA register bits will
return a ‘0’ when the button is released and a
‘1’ when the button is pressed.

Slide Switches: There are two slide switches
labeled SW1 and SW2. A read to the
corresponding GPIODATA register bits will
return a ‘0’ when a switch is down (toward the

LEDs) and

a ‘1’

when a switch is up (toward

the OLED display).

LEDs: There are four LEDs, labeled LD1 –
LD4. An LED will be illuminated when the
corresponding GPIODATA register bit is set to
a

‘1’

(given the corresponding direction bit has
been set in the GPIODIR registers) and off
when set to a

‘0’

.

I2C Bus

The I2C bus from the LaunchPad
microcontroller board is brought onto the Orbit
BoosterPack. There are three I2C devices on
the board: a 256 Kbit EEPROM, a temperature
sensor, and an accelerometer. In addition,
there is a connector for taking the I2C bus off of
the board to connect to additional external I2C
devices.

I2C Connector: Connector J5 can be used to
extend the I2C bus off of the board to connect
to additional external I2C devices. J5 is a
standard 2x4 pin header connector with 0.100”
spaced pins. It provides access to the I2C
signals, SCL and SDA, plus VCC3V3 and
GND. The VCC3V3 can be used to power
external I2C devices.

The I2C bus uses open collector drivers to
allow multiple devices to drive the bus signals.
This means that pull-up resistors must be
provided to supply the logic high state for the
signals. The Orbit BoosterPack provides 2.2 K­ohm pull-up resistors. Generally, only one set
of pull-up resistors are used on the bus.

Digilent has several small I/O modules
available that can be connected using the I2C
connector. These include a 4-channel, 12-bit
A/D converter, serial character LCD panel, 3-

www.digilentinc.com page 2 of 4

Copyright Digilent, Inc. All rights reserved. Other product and company names mentioned may be trademarks of their respective owners.