4D Arduino Adaptor Shield
4D Arduino Adaptor Shield Page 5 of 11 www.4dsystems.com.au
Jumper 1 (J1)
J1 enables the Display Reset to be changed from being triggered from the Arduino on GPIO D4 when in the AR position,
or from the H2 connector by means of an external source, when in the PR position. If the jumper is connected between
the AR pin and the central RES pin, then the display can be reset by setting D4 high in the Arduino logic, and then low
again. If the jumper is connected between the PR pin and the central RES pin, then the display reset is controlled via
the H2 Connector. This could be switched low by an external circuit, providing an external method of resetting the
display.
Removing the jumper from J1 entirely will disconnect the displays Reset from the Arduino completely, which may be
valid for some projects.
Note: D4 is always pulled low to GND via a 4.7K Resistor due to the nature of the reset circuit. So even if the J1 is
disconnected, the Arduino D4 input is always going to have a 4.7K pull down on it. In most cases this should not affect
operation of D4 if it is to be used for something else in a project when J1 is disconnected, however it should be noted
that this is the case when using this shield.
Jumper 2 (J2)
J2 enables the Power Source for the display to be changed from being powered via the Arduino’s 5V Supply, or via the
H2 connector. If the Arduino is powered from the Users’ computers USB, some computers cannot provide enough
current for both the Arduino and the Display to be powered off the same USB port, so auxiliary power can be required.
If J2 is connected between the AR pin and the central PWR pin, then the display is powered off the Arduino’s 5V
supply. If J2 is connected between the PR pin and the central PWR pin, then the display is powered off the H2
connector, via something like the 4D Programming Cable. 5V could also come from an external power source if
desired. Removing the jumper from J2 entirely will disconnect power from the display.
Jumper 3 (J3)
J3 enables the Serial signals from the display to be received either onto D0 or D2. D0 on most Arduinos is the Hardware
Serial Port 0 RX Pin. D2 is often used for Software Serial. This allows flexibility for different setups. If the jumper is
connected between the D0 pin and the central RX pin, then the Arduino’s hardware serial port 0 will be connected to
the display. In this configuration, programming of the Arduino is not possible without disconnecting the display, as
the USB programming signals for the Arduino will also be received by the display, which will result is corrupt
programming signals being received if the Display transmits anything, resulting in a failed programming attempt.
Disconnecting this jumper will disconnect the Arduino from the Display, allowing the Arduino to be programmed. If
the jumper is connected between the D2 pin and the central RX pin, this will allow Software Serial (or similar) to be
used to communicate to the display. The Arduino should be able to be programmed successfully when the jumper is
in this position without having to remove the display from H1 due to the display and Arduino not sharing the same
serial port as the Arduino’s USB programming.
If desired, a jumper wire can be placed from the central pin of J3, to a completely different pin on the Arduino, such
as D19 on an Arduino Mega, allowing Hardware Serial1 to be used. Jumper wires are not included.
Jumper 4 (J4)
J4 enables the Serial signal to the display to be transmitted from either the Arduino’s D1 or D3 pins. D1 on most
Arduinos is the Hardware Serial Port 0 TX Pin. D3 is often used for Software Serial. Please refer to the description for
J3 above, the same applies for J4. If the jumper is connected between the D1 pin and the central TX pin, then the
Arduino’s hardware serial port 0 will be connected to the display. If the jumper is connected between the D3 pin and
the central TX pin, will allow Software Serial to be used to communicate to the display. Removing the jumper will
disconnect the Arduino from the Display.
If desired, a jumper wire can be placed from the central pin of J4, to a completely different pin on the Arduino, such
as D18 on an Arduino Mega, allowing Hardware Serial1 to be used. Jumper wires are not included.