Evolution of a Blog

This blog has evolved as I have as a maker. It starts at the beginning of my journey where I began to re-tread my tires in the useful lore of micro electronics and the open-source software that can drive them. While building solutions around micro-electronics are still an occasional topic my more recent focus has been on the 3D Printing side of making.

Monday, February 16, 2015

Arduino Nano / LCD Projects Platform - Assembly

    1. Cut the header strips (10) into four segments of 15 pins each.  It
      is easy to cut these strips to size using a small wire cutter.  Simply
      position the jaws of the wire clipper over the pin where the cut is to
      be made (e.g. 16th pin from end in this case) and squeeze.  The cut
      should be pretty even as it will follow the cavity where the pin was
    2. Carefully solder the four header strips from above to the front of
      the PCB (side with labels).  Make sure that the header strips are flush
      with the PCB and that the Nano will fit into the inner two strips (see
    3. Double check that all the contacts have been cleanly and neatly
      soldered as the display module will cover these solder points once it is
      installed!!! Continuity test with a volt ohm meter would be a good thing.
    4. If you are planning on using the 5v power plug (3) then a two pair
      wire (not provided) should be soldered to the front of the board at this
      time as the solder points for the power plug will also be covered by
      the LCD once it has been installed. Note that the power plug can
      actually be installed after the fact but the ideal case is to do it now.
    5. Install the three pin jumper (6) for the LCD power option.   The
      default is to have the jumper on the PWM side but if you need every PWM
      pin then you can drive the backlight from the 5v power (though without
      brightness control). 
    6. The TFT LCD (2) module should have electrical tape covering the
      metal underside of the SD card slot.  Do not remove this!  If the
      electrical tape is missing then it should be replaced before proceeding
      as contact between the pins coming through the PCB and the metal SD card
      slot is bad!
    7. Install the LCD (2) and the three push buttons (5) on the reverse
      side of the PCB from the headers.   Make sure these items are mounted
      flush to the board and that the buttons are perpendicular to the PCB
      surface.  The bends on the button contacts should be facing long ways
      relative to the PCBs long dimension (Image 3).   It is important that
      these buttons be mounted at the same heights so the protroud evenly from
      the case!
    8. Finally, on the other side of the board from the LCD and the pushbuttons, there are spots where four 10k resistors should be mounted.  More about this in another aticle but these resistors create a three legged voltage divider, that in tandem with the pushbuttons, allow one input on the Nano to be used for three buttons.
    10. Here are images of the PCB ready to be inserted into the case.
    11. The PCB can now be inserted into the front of the 3D printed case
      (13) with the two wires for the power socket exposed through the power
      socket hole and soldered to the socket (if you are using said socket).
    12. If you are planning on using the six pin header (7) to expose pins
      to the outside of the case it should be mounted now (a little epoxy does
      the trick).   The left most pin of this header, when looking from the
      outside of the case, can be bent down and soldered to the PCB ground
    13. The back of the case can now be attached using the four screws
      (14).   The posts on the back of the case (12) should firmly press the
      PCB against the front of the case.   The reset button extender (15) can
      be used to make it easier to reset the Nano though this has the
      disadvantage of making an accidental reset possible!
Once assembled all pins of the Nano are available via the two headers.  Note, however, that a number of pins are used by various functions!   The pins that are available without caveat are D2, D3, D6, and D7 as well as pins A1 to A7.  The serial port pins, D0/Rx and D1/Tx are also available.  D5 can be available if you use jumper the Backlight to use constant 5v lighting rather than variable PWM lighting from pin D5.  Pins D4 and D12 can also be available but only if the SD Card functionality is sacrificed.

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