Datasheet
4D SYSTEMS 4DLCD-FT843 4.3” Embedded SPI Display
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4DLCD
-FT843 4.3” Embedded SPI Display
4. Hardware Interface Pins
The 4DLCD-FT843 Display features 10 physical pins
on the flex. This section describes each in detail.
Pin Detail
Pin 1: 3.3V - Power Input
This is the main power input pin for the display. It
powers not only the display logic itself, but also the
FT800 Video Engine on board the flex, along with
the backlight for the 4.3” display. The
recommended voltage is 3.3V, however the display
can be powered as low as 3.0V and as high as 3.6V.
It is however highly recommended to stay at 3.3V
for best results. This also enables interfacing with a
3.3V host processor easier, along with the interface
to a micro-SD or SD card, which is also
recommended to be at 3.3V.
Pin 2: SCK – SPI Clock
This is the Clock Input for the SPI Bus which comes
from the host. This is 3.3V logic and is not 5V
tolerant, please only connect 3.3V compatible
devices to this pin. The FT800 can run up to a
maximum of 30Mhz on the SPI Bus.
Pin 3: MISO – SPI Data Output
This is the SPI Data Output from the Display, which
goes to the Host processor. This is 3.3V logic and is
not 5V tolerant, please only connect 3.3V
compatible devices to this pin.
Pin 4: MOSI – SPI Data Input
This is the SPI Data Input for the Display, which
comes from the Host processor. This is 3.3V logic
and is not 5V tolerant, please only connect 3.3V
compatible devices to this pin.
Pin 5: CS – SPI Chip Select Input
This is the SPI Chip Select Input for the Display,
which comes from the Host processor. This is 3.3V
logic and is not 5V tolerant, please only connect
3.3V compatible devices to this pin.
Pin 6: INT – Configurable Interrupt Output
This is the Configurable Interrupt Output from the
display, which can be configured to be trigger by a
number of events, and is used to interrupt the Host
Processor when the interrupt event occurs.
This is an Open Drain output, which is pulled high to
3.3V by the display module, and is Active Low.
Please refer to the FT800 Datasheet from FTDI,
which is linked from the 4DLCD-FT843 Product Page
on the 4D Systems website, for more information.
Pin 7: PD – Power Down Input
This is the Power Down Input for the Display, which
can be triggered by the Host Processor if the display
is required to be powered down, either from a
standby state or from its active state.
This is pulled high to 3.3V by the display module,
and is Active Low.
Holding this pin low for >5mS will cause the FT800
Video Engine to shut down and go into a powered
down state. Releasing this low or driving the pin
High will cause the display to start up again.
It is also possible to reset the display using this pin,
by driving it low for 5mS and then high again.
Please refer to the FT800 Datasheet from FTDI,
which is linked from the 4DLCD-FT843 Product Page
on the 4D Systems website, for more information.
Pin 8: AUDIO_SHDN – Audio Shutdown
This is the Audio Shutdown output from the FT800
Video Engine, which is designed to enable/disable
an external audio amplifier based on the events
occurring on the FT800.
This pin is actually the GPIO01 General Purpose I/O
on the FT800, so could be used for an alternative
function if required.
Please refer to the FT800 Datasheet from FTDI,
which is linked from the 4DLCD-FT843 Product Page
on the 4D Systems website, for more information.
Pin 9: AUDIO_OUT – Audio Output
This is the Audio Output from the FT800 Video
Engine, which is a Push/Pull PWM Output capable
of Source/Sink of 16mA of current.
This pin is designed to be passed into a simple filter
circuit and then passed to an amplifier for best
results. Please refer to the example schematic in
Section 6 which provides the recommended circuit
to connect to this pin.
Please refer to the FT800 Datasheet from FTDI,
which is linked from the 4DLCD-FT843 Product Page
on the 4D Systems website, for more information.
Pin 10: GND – Power Ground
This is the Power Ground for the 4DLCD-FT843
Display. This should be connected to the GND
associated with the Pin 1 3.3V Power Input pin.