Assembling the "LED matrix shield" kit

Updated May 16, 2011
Fellow Arduino fan Scott graciously offered this PDF version of the assembling instructions.


Updated Feb 17/2010

The content of the "LED matrix shield" kit was slightly changed: the 40-pin female header used as socket for the LED matrix is now replaced with two 12-pin machined female headers, making a much better quality connector, suitable for the thin pins of the LED matrix.

Since these new headers are not as high, the IC sockets, if soldered, would impede on the complete insertion of the LED matrix in the headers; therefore, they have been dropped.

The LED matrix shield for Wise Clock kit includes the following components (also shown in the photo):

• PCB, Arduino shield format;
• 8x8 bi-color (red + green) LED matrix, medium size (47 x 47 mm);
• 1 x 40-pin male header;
• 2 x 12-pin machined female header;
• 17 x 100 ohm resistor;
• 1 x 10K resistor;
• 2 x 100 nF decoupling capacitor;
• 2 x 595 shift register;
• 1 x ULN2803;
• 1 x infrared receiver;
• 2 x mini push button.

Like Wiseduino, the LED matrix shield kit requires some basic soldering skills.
One of the most important aspects of correctly assembling the kit is paying attention to the orientation of the ICs and the LED matrix. The ICs must be positioned to match their notches with those on the silkscreen. Pin 1 (and also Pin 13) of the LED matrix are clearly marked on the silkscreen. To eliminate any doubt I also hand-wrote the pin numbers on the back of the LED matrix.

Following are the steps for assembling the board:

1. cut the male headers in 4 pieces (two 8 pins, two 6 pins) and solder them in their right places; the easiest way to perform the soldering is to insert the pins into the Arduino extension connectors, like you had a shield in place already;

2. solder the two 12-pin headers;

3. solder each 100 ohm resistor after placing it vertically (bend one terminal 180 degrees);

4. place and solder the 2 push buttons;

5. solder the remaining 2 resistors, R17 (10K) and R19 (100 ohms);

6. solder the infrared receiver, then bend it 90 degrees so it becomes parallel to the board and also sticks out a bit;
7. insert the 3 ICs, matching their notches with those on the silkscreen, then solder them (before inserting them, don't forget to bend their pins, as shown here);

8. solder the 2 decoupling capacitors (100nF);

9. carefully insert the LED matrix, paying attention to its orientation (the pin numbers are hand-written on the back, for easier identification).

In the end, the assembled LED matrix shield should look like this (shown plugged into Wiseduino):

The code for Wise Clock can be viewed and downloaded here.

Related posts:

• Introducing Wise Clock
• Introducing Wiseduino, an Arduino clone
• Wise Clock sketch