Here is a great project for educating youngsters (and others) about Amateur Radio and electronics in a fun and unique way that combines planning and building hardware along with running and enjoying new software. With the help and ideas from Jean Wolfgang, WB3IOS, I developed a simple matching game that can be used by many eager-to-learn individuals. Amazingly, I was able to develop and complete the hardware, software, and documentation for this project in just a few short weeks.

My goal was to create a project that would be as much fun to build as it would be to learn from. After sketching several different circuits to design a matching game, I decided to take a simple approach that requires only a handful of common components. This project was developed to be easy to assemble. Yet, it allows newcomers to the hobby of Amateur Radio to develop skills in planning projects, following directions, gathering parts, drilling holes, stripping and soldering wires, reading schematic diagrams, testing and troubleshooting circuits, and best of all… having fun!

The project is a game system for matching Ham-related terms, symbols, and figures that uses the

standard parallel port (SPP) on a PC as a hardware interface. To keep the construction easy, I decided that the simplest method was to use a PC to control the hardware. This way, no batteries are required, and otherwise complex circuitry is eliminated by emulating the control logic in software. You should be able to build the game board for less than $20 using all new parts. I built the prototype for under $3. The software that runs the game was written for use on Microsoft Windows 95 or 98, and was developed in Microsoft’s Visual Basic. The program uses direct I/O port access within the Windows 32-bit operating system.

The game board requires only a handful of components to complete, is easy to construct, and connects directly to the parallel printer port (LPT1, LPT2, etc.) on your personal computer. The instructor can observe a student’s connections and results on-screen from up to 25 feet away. The remote monitoring is provided by virtual simulation of the physical connections and displayed results within the Windows software.

Four outputs of the standard parallel printer port on a PC are used to sequentially drive a single logical low to each red banana jack, one at a time. The black banana jacks are connected to four input pins on the port. Each input from a black banana jack is tested to find the logical low signal. When the low signal is found on an input, the software "knows" which low output is connected to it. If the connection is correct (as compared to the program settings), a logical high is sent to one of the four corresponding LED output pins to turn the appropriate LED on. If the connection is determined to be incorrect, the LED output signal remains low to keep the LED off. The four pairs of inputs and outputs are normally high, and the four LED outputs are normally low. In case you are wondering why a printer port has input connections, the printer uses these input signals to communicate with the computer. For example, the printer can send a signal to the computer that signifies when there is no more paper in the printer. This interactive communication between the printer and computer is called "handshaking".

You can begin the fun by collecting all of the necessary hardware components and materials to build the game board.

8 Banana jacks, 4 red, 4 black (4 x RadioShack #274-725) 2/$0.99

4 Sets of 6" jumper leads with banana plugs at each end (4 x RadioShack #274-721) 2/$1.59

Use with four pieces of hookup wire or test lead wire

4 Green LED lamps with clear lens (2 x RadioShack #276-304) 2/$1.29

4 Resistors 150-ohms, 1/4W, 5% (1 x RadioShack #271-1312) 5/$0.49

1 DB-25-P (Male) D-sub connector, solder type (1 x RadioShack #276-1547) $1.49

Use with hookup wire or 1 to 25 feet of 25-conductor round cable

or

DB-25-P (Male) D-sub connector, insulation-displacement type (1 x RadioShack #276-1559) $3.99

Use with 1 to 25 feet of 25-conductor ribbon cable (1 x RadioShack #278-772) $3.99 (5ft)

1 10" x 12" panel made of cardboard, wood, plastic, or metal

a/r Solder (rosin-core)

8 Game cards (business card sized 3.5"W x 2.0"H)

8 Business card protectors - clear plastic (used as game card holders)

1 MatcHam for Windows 95/98 software

(Download for FREE from the Web at http://www.myhost.com/rdey/ar4kids.htm)

a/r Staples, nails, screws, tape, or glue (for securing card holders) (see text)

Once the parts are gathered, you can start building the board by creating a drilling template. Set a photo-copy machine for 150% enlargment, and copy the front panel layout onto an 11" x 17" or 11" x 14" sheet of paper. The banana jacks are mounted on approximately 1.75" centers horizontally, and 2.25" centers vertically. Although the dimensions are not critical, you can use these measurements to verify that your photocopy of the front panel layout is the correct size.

Align and tape the 11" x 17" (or 11" x 14") template to the front panel material, then center-punch all 12 hole locations. Next, drill 8 holes at 3/8" diameter for the banana jacks, and 4 holes at 1/4" diameter for the LEDs. Install the 8 banana jacks, with a column of red on the left side, and a column of black on the right side. Then, install the 4 LEDs. Use LED holders if available, otherwise, place tape on the back of the panel to hold the LEDs in place. Solder the 4 resistors onto the longest leads (anode side) of the 4 LEDs while referring to the schematic.

Use solid or stranded copper hookup wire to make all of the necessary connections. Any wire gauge from #20AWG to #28AWG should work fine. If you are using 25-conductor ribbon cable on this project be careful. It is unsafe for young students (or even adults) to separate the ribbon cable wires using a sharp knife. Also, the pin numbers on the connector are not in the same sequential order as the ribbon cable wires. Wire number 1 starts at the colored stripe on the cable, which connects to pin 1 on the connector. However, the pin numbers continue in the order: 14, 2, 15, 3, 16, 4, 17, 5, 18, 6, etc. As you can imagine, this is confusing, and may be frustrating for students.

If you decide to use the ribbon cable instead of individual wires, separate all 25 wires in the cable by slitting the insulation between the wires for a length of about 5". Whether you use a cable or wires, strip 1/4" of insulation off of the ends of each wire that is required to complete the wiring. Solder in place a piece of #22AWG buss wire about 8" long to each short lead (cathode side, on the flat side) of the 4 LEDs. Then, solder the hookup wire (or wires from the 25-conductor ribbon cable) to the jacks (and connector if required) and the other ends of the resistors, while referring to the schematic. Trim any unused leads.

Next, attach the card holders to the front panel using any number of techniques, depending on your choice of front panel material. If your panel is made of wood, you can simply staple, nail, or screw the card holders into place. For metal or plastic panels, use tape, glue, or screws. Then, label the front panel jacks as shown on the front panel layout.

Now, plug the connector into the parallel printer port on a PC. Use a standard 25-conductor parallel printer extension cable if needed. The game board should work just fine with cables even longer than 25’. However, some experimentation may be required with greater lengths of cable. Finally, install and run the MatcHam for Windows software to operate the game.

1. Set photo-copy machine to 150% enlargment, and copy panel layout onto 11" x 17" paper.

2. Align and tape 11" x 17" paper to front panel, then center-punch all 12 hole locations.

3. Drill 8 holes 3/8" diameter (for jacks), and 4 holes 1/4" diameter (for LEDs).

4. Install 8 banana jacks, column of red on left side, and column of black on right side.

5. Install 4 LEDs. Use LED holders if available, otherwise, place tape on back of panel to hold LEDs in place.

6. Solder 4 resistors onto longest leads of 4 LEDs while referring to schematic.

7. Separate all 25 wires by slitting insulation between wires for a length of about 5".

8. Strip 1/4" of insulation off of each wire.

9. Solder #22AWG buss wire in place to each short lead (on flat side) of 4 LEDs.

10. Solder wires from 25-conductor ribbon cable to jacks and other end of resistors while referring to schematic and trim unused leads.

11. Add card holders, and label front panel jacks as shown on panel layout.

12. Connect ribbon-cable connector to parallel printer port on PC, using a 25-conductor extension cable if needed.

13. Install and run MatcHam for Windows software to operate the game.

Most parallel printer ports should be capable of driving the outputs to a logical high level of 2.4V minimum (3.1Vdc typical) with up to 2.6 milliamperes minimum. Typically, these values will be higher (2.5Vdc @ 12mA), and are adequate for driving each LED lamp. Technically-challenged readers should skip the next paragraph. None of the following changes should be required. These modifications are strictly for "Techies" that demand brighter LEDs.

To boost the LED current even more, install eight high-conductance (schottky) diodes with each anode end on each of the following connector pins: 2, 3, 4, 5, 6, 7, 8, and 9. Connect the cathode (banded) ends of each pair of diodes together. For example, connect the cathode junction of the pin 2 and pin 3 diodes to the A LED. Continue, by connecting the cathode junction of the pin 4 and pin 5 diodes to the B LED. Do this to the remaining two pairs of diodes to connect the C and D LEDs. These "steering" diodes will help to protect the port from damage if any shorts or other over-current conditions occur. Another way to increase LED drive current is to connect the LEDs to an externally-supplied positive 5-volts dc, and let the outputs sink the LED current instead of sourcing. In this case, you will need to reverse the direction of the LED connections, and choose the program option to sink LED current. To use both techniques for increasing LED drive current, you will need to reverse the direction of the diodes also.

To play the board game, simply insert eight game cards of your choice, and set the program settings for the correct results. Then, you can sit back and watch the computer screen, while the student attempts to correctly match the cards. When he or she connects the jumper wires, you will see the connection on your screen, and a simulated LED will light up green for correct matches, or red for incorrect matches. I originally created more than 50 different game cards to choose from, with many more card ideas in mind for future publication.

Place four of the same type of cards (word cards for example) into the card holders on the left side of the game board, then place the matching cards on the right side of the board. Once your setup is complete, and the software is running, you can ask the student to place the four wire jumpers into the appropriate places to correctly identify the cards on the right. One method of playing the game is to place the word cards on the left, and the schematic cards on the right. For example, place the "Resistor" card near the first red jack in position 1. Then, place the schematic symbol for a resistor near the second black jack in position B. Other possibilities include using combinations of the word cards, schematic cards, and picture cards.

The game board will only function correctly while it is connected to a printer port, and while the MatcHam for Windows program is running on the PC. Ignore the status of the LEDs until the software is running. Typically, the second LED in position B will be on before the program is started. Although, even this condition cannot be guaranteed. You can download the software for FREE from the following web site address.

The MatcHam program was designed for use on Microsoft Windows 95 and Windows 98 only. The software will not run on Windows NT, or 16-bit operating systems, such as Windows 3.1x.

If you have never installed Windows-based computer software before, you should seek help from a knowledgable friend before trying to start this install on your own. The software installation consists of uncompressing, (called unzipping) the Matcham.zip file, and running the Setup.exe file. After downloading the Matcham.zip file (about 1.4MB) from the Web, create a new folder with any name that you prefer. Unzip the file using WinZip or a similar program into this new folder. Then, run the Setup.exe file to begin the installation. Once the install process has started, follow the on-screen instructions for the remainder of the install.

Running the program is easy. Once the correct answers are set, the software simply stays on the screen and actively displays all results. Start the program from the Windows task bar, by clicking on Start, Program, and then MatcHam.

Before a student can play the board game, you must set the correct answers by checking the Show settings check box. Then, set the corresponding numbers (1 through 4) for the correct matches at jacks A through D. Most users will not need to change any of the hardware options, but here is how to do just that. Check the Show options check box to change the direction of the driving current flow on the four LEDs. The default is to source the LED current as shown in the schematic. Click on the current direction that your game board requires. Also, you can change the base I/O port address while the options are shown. The default port address is a hexadecimal value of 378, which is typical for computers that have only one parallel printer port available. This port is usually called LPT1, for line printer number one. If any of the "Show" check boxes are checked, you can click on them again to hide (uncheck) the settings or options. This is useful when you do not want anyone to see the correct answers.

To quit the program, click on the "X" (for exit) in the upper right hand corner of the MatcHam window, or press the <Alt> and <F4> keys simultaneously while the window is active. This will close the MatcHam window, and end the game. At this point, the game board will no longer function properly. The settings and options are not saved for the next time you start the program. The program starts each time with the default values. Future versions of MatcHam for Windows may retain the settings and options after being shut down.

I certainly have enjoyed putting this simplified training system together. I hope you and your students will have fun building and using it too. Good luck!

1. Front panel layout artwork
2. Schematic diagram
3. Some of the seven sheets of game card artworks. Each page contains artwork for 8 cards. 56 cards total.