User manual

4D SYSTEMS Armadillo-43(T) – Linux based Computer Display Module
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Armadillo-43(T) – Linux based Computer Display Module
USB Host 5.9.
The Armadillo features a single USB port which is a
USB Host.
The USB Host is capable of connecting to a wide
range of USB peripherals, such as a USB
Keyboard/Mouse, USB Hub, USB Hard Drive, USB
Flash Drive, USB Ethernet Dongle, USB WiFi Dongle
etc.
Using a USB Hub will enable additional USB
Devices to be connected together.
Since the Armadillo-43T utilises the same
processor as the Raspberry Pi, the following
website can be used to assist identifying possible
compatible and incompatible devices.
http://elinux.org/RPi_VerifiedPeripherals
microSD Card Socket 5.10.
The microSD card socket on the Armadillo is used
to hold the image of the Operating System which
is to boot on the Armadillo. It is required and there
are no options to use the Armadillo without having
a microSD card installed.
4D Systems offers suitable microSD cards for use
with the Armadillo, and are ‘Industrial Grade’ Class
10 cards which have advanced firmware for
preventing Read Disturb which is common in
systems that do a lot of reading of data without
necessarily writing over that data. It also offers
wear levelling technology, which is useful in a
system like the Armadillo due to the microSD is
essentially acting as a Hard Drive.
If alternate cards are required you can refer to the
following website which provides information on
tested SD cards (not specifically microSD cards
however) which work on the Raspberry Pi, and
therefore will be the same on the Armadillo-43T.
http://elinux.org/RPi_SD_cards
The microSD card socket itself is connected to the
Armadillo on Bank2 of the BCM2835’s GPIO banks,
and is connected to the SD0 interface.
Signal Name
GPIO Number
Description
SD0_CLK
GPIO48
SD Clock
SD0_CMD
GPIO49
SD Command
SD0_DAT0
GPIO50
SD Data bit 0
SD0_DAT1
GPIO51
SD Data bit 1
SD0_DAT2
GPIO52
SD Data bit 2
SD0_DAT3
GPIO53
SD Data bit 3
TFT LCD Display Backlight 5.11.
The Armadillo features a DC/DC Boost converter
for driving the backlight, due to the backlight
requiring a much higher voltage than the
Armadillo’s input voltage.
It utilises the TI TPS61080 0.5A DC/DC Boost
Converter, which is configured in a way which
allows for a PWM input, to enable the backlight to
be dimmed if required.
Due to the BCM2835 SoC only having 2 hardware
PWM channels, the backlight driver does not
utilise any of these hardware PWM signals, as it
was opted to keep these available for the User for
Audio or alternative applications. Instead it uses a
standard GPIO which has a driver written to map it
to the PCM clock, which allows a hardware-like
PWM output to be generated. Please refer to
‘Special PWM’ section for more information. This
ensures that the backlight PWM is stable,
compared to if the PWM was software driven, as if
system load increases the backlight intensity may
change, which would be undesirable.
The backlight control signal is linked to GPIO43,
and can be set as a simple digital GPIO and only
used for On/Off control of the backlight, or it can
be used in PWM mode, and a range of 0-100%
duty cycle on the PWM will set the backlight
brightness. By default, the Armadillo controls the
backlight with a 130Hz PWM.
A Backlight driver has been written to simplify the
interface for controlling the backlight.
Please refer to the “How To” section, and the area
titled “Control the LCD backlight”, for more
information.