Hardware Description
16
January 6, 2010
Fast response
Control Interface
The OLED display has a built-in controller IC with synchronous serial and parallel interfaces.
Synchronous serial (SSI) is used on the EVB as it requires fewer microcontroller pins. Data cannot
be read from the OLED controller; only one data line is necessary. Stellaris® Firmware
Development Package (included on the Documentation and Software CD) contains complete
drivers with source-code for the OLED display.
Power Supply
A +15-V supply is needed to bias the OLED display. A FAN5331 device from Fairchild combines
with a few external components to complete a boost converter. A few external components
complete the switching power supply. When the OLED display is operating, a small amount of
power can be drawn from the +12-V rail to power other devices.
Design Guidelines
The OLED display has a lifetime of about 13,000 hours. It is also prone to degradation due to
burn-in, similar to CRT and plasma displays. The quickstart application includes both a screen
saver and a power-down mode to extend display life. These factors should be considered when
developing EVB applications that use the OLED display.
Further Reference
For additional information on the RiT OLED display, visit
www.ritekdisplay.com
.
Other Peripherals
Speaker
A small, magnetic audio transducer connects through a MOSFET to
PD1/PWM1
, allowing a range
of options for generating simple and complex tones. Use of the +5-V rail reduces switching noise
on the +3.3-V rail.
Push Switches
The EVB has five general-purpose input switches. Four are arranged in a navigation-style
configuration. The fifth functions as a Select switch.
User LED
A user LED (
LED1
) is provided for general use. The LED is connected to
PG2/PWM0
, allowing the
option of either GPIO or PWM control (brightness control). Refer to the Quickstart Application
source code for an example of PWM control.
Bypassing Peripherals
Excluding CAN and JTAG, the EVB’s on-board peripheral circuits require 13 GPIO lines. This
leaves 40 GPIO lines and 4 ADC channels immediately available for connection to external
circuits. If an application requires more GPIO lines the on-board hardware can be disconnected.
The EVB is populated with 3 jumper links, which can be cut with a knife to isolate on-board
hardware. The process can be reversed by installing 0603- 0-ohm chip resistors.