Parts Inventory -- Make
sure you have all parts shown in the various items picture
above. Note that you might not have purchased some of
PCB Preparation -- Using
a fine-blade hack saw (or equiv), cut out the "X" areas in
each corner of the pcb to allow it to fit into the
enclosure. Be careful to cut "on the inside" of the
lines for the corner between J7and J2 so you don't
accidently cut the nearby trace on the bottom-side.
Attach Connectors -- J1 (power), J5 (keyboard), J6 (serial),
J12 (2x20 display connector), and J8 (28-pin IC socket for
U1). Note that J5 may have a metal shell, which fits
into available holes.
Attach Power On/Off Switch --
S1 must be mounted straight (perpendicular to board edge and
flat against it.
Attach the 5V and 3.3V
"voltage regulator" components (caps too) -- 5V VR1 ("462NL53B"),
3.3V VR2 ("ZLDO17-33"), C8, C9, C10, C11, C12 and C13.
Note that the "negative" side of the electrolytic tin can
are indicated with a black stripe. Be sure you have
the orientation/polarity correct, and especially for C13,
which is oriented differently from the others.
[NOTE: We previously indicated that the large tab
on the VR2 package shouldn't be soldered down to the pad ...
It's really okay to do this, and you should for best
Test Board Voltages --
Apply power to the 2.1mm coaxial power connector J1 and
press the S1 switch "in" to turn the board on. Measure
12V, 5V and 3.3V at the respective marked test point (pads)
near each regulator. Do not proceed until you ensure
that you have the specified voltages on the test pads.
Attach Q2 and VR4 --
These little SOT-23 packages look alike. The package
ID for Q2 is "1P", and the package ID for VR4 is "RKA".
Attach U2, U3 and U4 Integrated
Circuits -- Carefully noting the pin 1 location for each
IC, insert and solder U2 and U3 (larger 20-pin DIP ICs), U4
(AD8307, the 8-pin SOIC). NOTE: The "U4"
location is actually labeled "U7" on the pc board.
(Oops!) Also, DO NOT yet insert U1 (the pre-programmed
28-pin dsPIC controller) into its socket.
Attach Q1 "2N7000" --
This TO92 package with its 3 leads on a "cardboard strip" is
a MOSFET transistor. Be sure to handle with anti-static care, form the leads to fit into
the offset pad locations, oriented with the flat side of the
transistor as indicated on the silkscreen.
Attach All Remaining Parts --
Be careful to note polarity/orientation of the small SMT
Note 1: The polarity of the speaker SPKR in upper-left
corner of the pcb. (+ sign in indicated on bottom of
Note 2: The 10uF SMT
capacitor C23 located near U4 is non-polarized, so it
doesn't matter which way you attach it.
Note 3: C5 is
supplied as a surface mount device (SMD) chip capacitor,
yet the board layout/silkscreen is for a larger
electrolytic capacitor. (Oops.) The SMD cap is
correct, so solder either end to one of the pads, and
use a short wire to connect the other end of the cap to
the other pad.)
Attach Programming Connector
ICD1 -- Mount this 2x3 pinheader on the bottom side
of the pcb.
Attach 4 PCB Mounting
Standoffs -- Using the parts from the Enclosure Hardware
bag, attach the four aluminum standoffs on the bottom side
of the pcb, using the short 2x56 (smaller thread) screws.
Attach 2 Display Mounting
Standoffs -- Using the two, shorter 4-40 threaded
aluminum standoffs to the top of the pcb next to J2 and J3
Attach U6 to Bottom of QVGA
Display -- Noting orientation of pin 1 on U6 (256 Kbit
EEPROM), attach to the IC1 position on the bottom of the
DC Levels ... Before
installing the dsPIC microcontroller and display module,
make one final check of the DC power levels.
U1 and Display ... Install
the pre-programmed dsPIC processor U1 and the QVGA display module, making sure the display
connector is properly lined up with the connector on the PCBA. Do not install the MSNA assembly in its enclosure
until completing all the steps in this guide. You will need
access to components on the back of the main PCBA for
On! ... Leave
the SD card out, the keyboard unplugged, and then turn power
Screen is Displayed ... After
a pause of up to five seconds, you should see the splash
screen showing the firmware revision level. (If you hold
your finger on the screen while the splash screen is
displayed, the splash screen will be displayed until you
raise your finger.)
Beep ... The
splash screen will be displayed for about 3 seconds and then
the Terminal mode screen will be displayed (top line for
keyboard input, blue area for output received from the
serial interface). You may also hear "GO" BEEPed in
Morse code ("--.
Far So Good ... If
you got this far, there’s a good chance that everything is
in Keyboard ... Turn
power off, plug in the keyboard, and turn power on again.
LEDs Flash ... You
should observe the same power up sequence as before except
this time you will see the LEDs on the keyboard flash twice,
the first time when power if first turned on and the second
time when the splash screen is finished and the MSNA resets
and initializes the keyboard. You should also hear a BEEP
at the time of the second LED flash.
and See Text ... At
this point, characters typed on the keyboard should appear
on the input line. Pressing Enter on the keyboard
will send the text out the serial interface (3.5m stereo
jack) and clear the input line. Pressing and releasing the
Insert key will toggle the INS/OVR indicator in the
upper right corner of the display. Pressing Home
will clear any text on the input line.
Loop-Back Connector ..
loop-back connector for the serial port that connects RxD to
TxD and connect it to the serial port. Now when you press
Enter on the keyboard, any text on the input line
will be sent out the TxD line and received back on the RxD
line and displayed in the blue output area of the display.
Pressing Alt-Home will clear any text in the output
Lock is Important ...
release the Scroll Lock key on the keyboard and
observe the Scroll Lock LED turning on. This indicates
successful two-way communication with the keyboard. (The
Caps Lock and the Num Lock keys and the
associated LEDs should also be working.)
Command Mode Menu ... When the
Scroll Lock LED first comes on, the Command mode menu will
1) Clock Display
2) GPS Satellite Display Screen
3) Terminal Data Entry
Baud Rate ... Select
Command mode (press and release Scroll Lock) again
and Select B (Serial Interface bps) to display the BAUD RATE
menu. Select 7 (38400 bps, the default) and press Enter
to save your selection to EEPROM.
18. Mounting the PCB Assembly (PCBA) in the Enclosure ...
everything is working, you can mount the MSNA in its
enclosure by carefully angling the PCBA into the milled
enclosure. It may help to push in the S1 power switch
so it doesn't stick out quite as much, thus giving you a
little more room. Use the four remaining 2-56 screws (7/16")
to attach the PCBA through the four holes on the bottom side
of the enclosure. Some "compliance" was designed into
the mounting arrangement to allow you to slightly adjust the
position of the PCBA. Start by loosening the four pcb
mounting screws on the top of the board, then loosely screw
in the four longer screws on the bottom of the enclosure.
Align the PCB so all connectors and switches protruding from
the sides of the enclosure are centered within their cutout
areas, then carefully tighten down the eight screws that
hold everything together.
Attaching the Front Panel Overlay ...
Apply strips of double-sticky tape around the backside
perimeter of the laminated Overlay. (Scotch brand
"Scrapbooking Tape" p/n 34-8700-9324-1 is perfect, but any
double-sided tape, rubber cement or glue works well too.)
With the enclosure lid screwed in place, carefully place the
Overlay on the front panel, ensuring that the four holes in
the corners are aligned over the four black screws that
mount the lid to the enclosure body. Firmly press down
on the Overlay (where the tape/glue is beneath) to ensure a
sufficient adherence to the plastic lid.
Calibrating the Touch Screen ... Once you
have mounted the MSNA in its enclosure and verified
everything is still working, let's calibrate the touch
calibration function is started by touching the touch screen
when power is first turned on.
you see "TAP EACH CROSS" displayed, stop touching the screen
and the first cross will be displayed.
the center of the cross with a stylus. This is best done by
touching the screen and dragging the stylus to the center of
the cross and then raise the stylus. The MSNA records the
last point touched before raising the stylus.
the each cross has been touched, another cross will be
displayed. Touch each in sequence until all nine crosses
have been displayed and touched.
the last cross have been touched, the display will change to
a simple Etch-A-Sketch screen with two buttons at the
bottom. Use your stylus to draw on the screen and see how
close the drawn line follows the point of your stylus.
you are satisfied with the touch screen calibration, touch
the EXIT button and the MSNA will save the calibration data
in EEPROM and start normal operation.
you are not satisfied with the touch screen calibration,
touch the REDO button and the touch screen calibration
sequence will restart.
the GDT with an external GPS receiver via the serial data