The LCDuino-1 display I/O processor

Instructions

Before you start

You can print out an image of the circuit board silkscreens (top side, bottom side, both in PDF format) to use as a guide for installing components.

While you look at the board layout, please also take the time to look at the schematic diagram and associate each part with their location in the circuit. While this is not normally required to build a working circuit, one of the opportunities of DIY is to learn about how the circuit works. Try to determine what each part does and why the particular part or value is chosen. There are many web resources to help you with this, including the AMB DIY audio forum. You will find the overall DIY experience more rewarding as a result.

LCDuino-1 board assembly instructions

Clean both sides of the blank LCDuino-1 board with paper towel and isopropyl alcohol or electronics flux remover before soldering any parts on it.

Some parts are optional. See the Parts list for details.

Most parts are to be mounted on the top side of the board (and soldered on the bottom), but there are a few parts that should be just the opposite (VR1, X2, SW1, both LEDs and all Molex KK 254 headers). The board silkscreens also show which side each part should be mounted. Note that the horizontal style of the supercapacitor (Cs) should be mounted on the top side of the board, but the vertical style should be mounted on the bottom side.

Do not install the J1 and J2 pin headers at this time, these are deferred to the Display module instructions section below.

γ3 only: Do not populate the real time clock chip (U2) and its socket, the quartz crystal (X2) and the supercapacitor (Cs).

Volu-Master only: If you will be installing the real time clock chip (U2), the first thing is to mount the cylinder crystal (X2) on the bottom side of the board and solder it on the top side, before you install the IC socket for U2. Bend a cut resistor lead into a U-shape, slip it over the crystal and insert the lead ends into the two holes on the board, on each side of the crystal. Solder the leads to the board on the top side of the board as a way to secure the crystal. When done, it should look like the photo below.



Then, solder the remaining components to the board. Do one side at a time, starting with the lowest profile parts and work your way up. There are two basic mounting options for the IR receiver (U4):
  1. Wired off-board and mounted on the front panel as shown in the photos below (with the "dome" exposed to the outside through a hole on the panel). See AMB's reference α10 pre-amplifier or γ3 DAC.
  2. Mounted directly on the top side of the board (with the leads bent 90°).
The first mounting option is shown in the photos at the bottom of this page. The following diagram illustrates the second option.



Note: The second mounting option requires a wider panel cutout for the display module, in order to expose the IR receiver. A clear/tinted piece of plastic lens could then be mounted in front to finish the look. Also, the IR receiver's leads should be insulated individually with heat-shrink or other tubing in order to prevent short circuits between the pins, or to circuitry on the display module. Be sure to connect the IR receiver correctly. It will be damaged if the wiring is reversed.

LED13 is an "activity light" which, by default, flashes when a valid command is received from the IR remote control. You may solder it on the board, or mount it on the front panel and wire it to the board.

Make sure the correct part goes into each position on the circuit board. Measure each resistor with your multimeter to ensure it's the proper value. Pay attention to the polarity of electrolytic capacitors, and the orientation of the trimpots and IC sockets. Install the ICs into their sockets after you're done with all the soldering, and make sure each one is seated completely.

Due to U1's 28 pins, if you chose to use a socket with machined contacts, a considerable amount of force will be needed to insert the IC fully or to remove it from the socket. Be careful so that you do not bend or break the IC pins or damage the socket. Also take extra care to avoid pricking your finger on the pins.

For γ3 only, you should break the 9P single-row 0.1" pitch pin headers into two 3P and one 2P pieces, Then, mount them on the back of the LCDuino-1 board in the _D2/_D3/_D4, _D5/_D6 and _D10/_D11/_D12 positions. See the Wiring section for information about how these will be used to connect more signals between LCDuino-1 and γ3.

Clean up the solder flux residue from the board with isopropyl alcohol (or electronics flux remover) and a brush.

Display module instructions

You may need to enlarge the display module's four mounting holes slightly in order to fit imperial #4-40 or metric M3 machine screws through them.

To ensure proper alignment and electrical contact, the LCDuino-1 board's J1 and J2 pin headers should be mated to their matching 6P female pin receptacles, and then soldered to the LCDuino-1 board and the display module while they're bolted together on their mounting standoffs.

Make sure that the two 6P receptacles go in the correct pads on the display module. Use the row of pads on the top side of the back of the display module. There is a row of 16 pads. The two 6P receptacles should be soldered to pads 1-6 and 11-16. There are four unused pads in the center. See the following photo (click image to enlarge):



Plug the LCDuino-1 board into the display module via the J1 and J2 connectors.

Miscellany

Since the LCDuino-1 and display module board holes are plated through, you only need to solder the parts on the opposite side of the board that the part is mounted on. Do not drill or enlarge the holes because that would damage the through-plating.

Inspect all solder connections carefully, using a magnifying glass, to make sure there are no solder bridges or cold solder joints. Use a multimeter in ohms scale to check for short circuits, and correct any mistakes.

When all steps on this page are completed, proceed to the Wiring & ground section for details about wiring up the connections to the board.

Photos of the top and bottom sides of an assembled LCDuino-1 board, and mated to the display module as a "backpack" (click image to enlarge):



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