Digilent 6032-410-000P-BOARD - Manual (Page 2)

Orbit BoosterPack Reference Manual
www.digilentinc.com page 2 of 4
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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’ .
I
2 C Bus
The I
2 C bus from the LaunchPad
microcontroller board is brought onto the Orbit
BoosterPack. There are three I
2 C devices on
the board: a 256 Kbit EEPROM, a temperature
sensor, and an accelerometer. In addition,
there is a connector for taking the I
2 C bus off of
the board to connect to additional external I 2 C
devices.
I
2 C Connector: Connector J5 can be used to
extend the I 2 C bus off of the board to connect
to additional external I 2 C devices. J5 is a
standard 2x4 pin header connector with 0.100”
spaced pins. It provides access to the I
2 C
signals, SCL and SDA, plus VCC3V3 and
GND. The VCC3V3 can be used to power
external I
2 C devices.
The I
2 C 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 K-
ohm 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 I
2 C
connector. These include a 4-channel, 12-bit
A/D converter, serial character LCD panel, 3-