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Build Your Team A Professional Sports Scoreb Because of its modular construction, our new Electronic Scoreboard is easy to build. This month, we describe the assembly of the Control Console and the main control board in the display unit. I N ALL, THERE are some seven modules to build for the Electronic Scoreboard – two for the control console and five for the main display unit. We’ll start with the assembly of the control console modules. As shown in the photos, the Scoreboard’s control console is built into a compact sloping-front ABS plastic case. This case measures 189 x 134 x 70  Silicon Chip 32/55mm and is listed in the Jaycar catalog as HB-6094. Inside the case, most of the circuit components are mounted on a PC board measuring 178 x 111mm and coded BSBKYBD1. This fits snugly into the lower half of the case. The only remaining components are the keyswitches and the two indicator LEDs, which mount on a second smaller PC board measuring 163 x 100mm and coded BSBKYBD2. This switch board fits inside the top of the case, behind the front panel, and the two boards are connected together via a short length of 16-way ribbon cable fitted with IDC connectors. The switch board is the easiest to assemble, so it can be built first. Fig.6 shows the parts layout diagram and siliconchip.com.au Pt.2: By JIM ROWE board as you can see, there is very little involved. Start by fitting the seven wire links. These all run vertically down the centre of the board and can be made using tinned copper wire or resistor lead offcuts. That done, fit the 90° 16way DIL connector (CON3) (the other vertically mounting header goes on the main console control board). The 13 key switches can go in next. These all have four connection pins, plus two moulded plastic locating pins near diagonal corners, so they can only be fitted one way around. The main thing to watch is that you fit the correct This view shows the completed switch board that’s used in the control console. Follow this to install the correct keytop colour in each location. colour keytop to each switch – just use the photo as a guide. Note that the keytops are fitted by holding them at about 40° to the top of the switch body, so the two rear “hinge tabs” will slip down evenly into the recesses on each side of the rear of the switch. The keytops are then pushed down until the hinge pins click into place and the actuator rods also click in. That done, check that the switches operate correctly. They should operate with a distinct click each time you press the keytops. Once the switches are in, the only Fig.6: check that the switches are seated properly on the switch board before soldering their leads. siliconchip.com.au April 2005  71 Fig.7: follow this diagram carefully when installing the parts on the main console board. Note that the two DIP switches must be fitted with their “ON” sides to the left. remaining components to fit to this board are the two indicator LEDs. These mount vertically, with the lower surface of each LED body about 10mm above the PC board itself. Use a green LED for LED1 and a red LED for LED2 and make sure they are orientated correctly. Main console board The next step is to assemble the main console board – see Fig.7. Begin by fitting the two wire links, followed by the resistors and the small non-polarised ceramic, monolithic and MKT capacitors. The three larger electrolytic capacitors are fitted after these, making sure they go in the correct way around. Note that all three electros must be mounted on their side as shown in Fig.7, to ensure adequate clearance between them and the keyswitch board when the console is later assembled. Now for the semiconductors. Begin 72  Silicon Chip by fitting the four diodes (D1-D4), taking care to ensure that a 1N4004 power diode is used for D1 (D2-D4 are all 1N4148 signal diodes). Make sure you fit all four with the orientation shown in the diagram. Follow these with the seven transistors and again check Fig.7 carefully to ensure each one has the correct orientation. Note also that the two PN200 transistors go in the Q1 and Q3 positions, while the five PN100 transistors go in the remaining positions. The two 14-pin ICs – IC2 (74HC132) and IC3 (74HC74) – can go in next. Install them with their notched ends orientated as shown on Fig.7. They are both CMOS devices, so take the usual precautions to prevent damage due to static electricity – ie, earth the barrel of your soldering iron and solder their power supply pins (7 & 14) to the board pads before the remaining pins. The 4MHz crystal (to the right of IC1 is next on the list. It should be pushed right down onto the PC board, before soldering its leads. Be careful not to overheat the leads, to prevent damage to the crystal inside the metal case. Now fit the two 4-way DIP switches. These must both be installed with their “On” sides to the left. Note, however, that only one switch in each group should actually be slid into the “On” position. In the case of DIP switch S1 (the frequency channel select switches), we suggest that you initially set the “1” switch on, so that you can try using this frequency channel first. However, when it comes to S2 (the basketball code select switches), you will have to move either the 1, 2 or 3 switch to “On”, according to the basketball code you’ll be playing (see Table 1 last month). CON1, the 2.5mm concentric power input socket, can go in next. Note that you may need to enlarge the mounting slots slightly with a jeweller’s needle siliconchip.com.au The completed console control board is secured in the bottom half of the case using self-tapping screws. Take care with the DIP switch settings, otherwise the unit won’t function correctly – see text. file, so the socket lugs will slip through them. That done, fit the 16-way DIL header (CON2). It must be mounted with its centre-locating slot towards the left, as shown in Fig.7. Next, fit the 18-pin DIL socket for the PIC microcontroller (IC1). This should be fitted so that the end recess is at the top, near DIP switch S2 (so that you will later install the IC the right way around). Now for the +5V regulator REG1. This is fitted by first bending all three of its leads down by 90° 6mm from the regulator’s body. That done, the regulator and its matching U-shaped heatsink (6073B type) can be attached to the PC board using an M3 x 6mm machine screw, nut and lock washer. Check carefully that everything is correctly aligned before soldering the three leads. That done, the AWM609TX data transmitter module can be installed. Again, you may need to enlarge the siliconchip.com.au mounting slots in the board slightly, so that the mounting lugs will all slip through. The lugs are then soldered to the copper underneath to secure the module to the board, after which its 10 connection pins can be soldered to their respective pads. Once the transmitter module is in place, solder a 31mm length of 1mm brass wire to the centre pad at the top left. This serves as the module’s transmitting antenna (31mm corresponds to a quarter of a wavelength at 2.4GHz). The main console board can now be completed by plugging the programmed PIC16F84A microcontroller (IC1) into its socket. Be sure to install it with its notched end towards DIP switch S2. Console assembly The completed console control board can now be mounted inside the bottom section of the console case. This is done by first slipping the an- tenna wire through a matching hole in the rear and then lowering the board until it’s sitting neatly on the moulded plastic mounting pillars. Four 4G x 9mm self-tapping screws are then used to secure it in place. A short length of 16-way ribbon ca- Where To Buy A Kit Jaycar Electronics has sponsored the development of this project and they own the design copyright. A full kit of parts will be available from Jaycar in due course – Cat. KC5408. This kit includes a pre-built wooden display frame with screenprinted lettering and individual Perspex covers for the displays; screen-printed and solder-masked PC boards; all on-board parts; and a control console case with a prepunched front panel and screened lettering. April 2005  73 The 16-way ribbon cable should be plugged into the switch board before mounting the latter in the top section of the case. As with the control board, it’s secured using selftapping screws. ble is used to connect the two console boards together. This is only about 70mm long and is fitted with two 16way IDC line sockets. These sockets must be fitted as shown in Fig.8, so that the cable can link the two board headers without problems when the case is assembled. Once the cable has been made up, plug its end socket into the 16-way DIL header on the keyswitch board. That done, place this board inside the top section of the case, with its switch keytops passing through the matching rectangular holes in the front panel and the two LEDs passing through the round holes. The board can then be secured using five 9mm x 4g selftapping screws. Finally, plug the socket at the other end of the 16-way ribbon cable into its header on the main console board and dress the cable so that the two halves of the case can be swung together. The two case sections can then be fastened together using the four self-tapping screws supplied with it. That’s it – the control console is now ready for use. Main control board Fig.9 shows the assembly details for the main control board used in the scoreboard. Begin by fitting the 14 wire links which can be made from resistor lead offcuts or tinned copper wire. The only exception is the first link immediately to the left of IC2 and IC3. This link should be run using insulated The 31mm-long brass antenna wire protrudes through a hole in the side of the console case. This photo shows the top half of the console case, prior to installing the switch board. 74  Silicon Chip siliconchip.com.au Fig.8: here’s how the sockets are fitted to the 16-way ribbon cable that connects the console boards. hookup wire, so there is no chance of it being able to contact either the adjacent IC pins or the equally long link on its left. Once the links are in place, fit the single PC board terminal pin. This goes near the centre right of the board, to provide test point TP1. That done, you can install all the smaller components, including the resistors, diodes, crystal X1 (10MHz) and the capacitors. Be sure to fit the tantalum capacitors and the diodes with the correct orientation, as shown on Fig.9. Similarly, take care with the orientations of the transistors. In particular, Brand New From SILICON CHIP note that Q11 is a PN200 PNP transistor, while Q1, Q9, Q10 & Q12 are all PN100 NPN transistors. Q2-Q8 are all MTP3055 power Mosfets. Each device is installed by first bending its leads down by 90° 7mm from its body and then fastening the device to the PC board using an M3 x 6mm screw and nut. Attach all the devices to the board in this manner, then solder the leads and trim the excess lead lengths. Don’t solder the leads before bolting the device tabs to the PC board. If you do, it could place strain on the solder joints when the mounting screw is installed, which could then crack the copper pads. The 5V regulator (REG1) is installed is exactly the same way, except that it’s fitted with a 6021 type U-shaped heatsink. Before assembly, apply a thin smear of heatsink compound to the underside of the regulator, to ensure that there’s a good thermal bond between it and the heatsink. The four CMOS ICs – IC2, IC3, IC4 & IC5 – can go in next. These are all CMOS devices, so be sure to observe the usual anti-static precautions (ie, 160 PAGES 23 CHAPTE RS Mail order prices: Aust: $A22.50 (incl. 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Note that DIP switch S1 (channel select) must be set to match DIP switch S1 in the control console. earth the barrel of your soldering iron and solder their supply pins first (pins 7 & 14 for IC4 & IC5, pins 8 & 16 for IC2 & IC3). Make sure that these devices are all correctly orientated 76  Silicon Chip and that the correct device is used at each location. As on the main console board, the PIC microcontroller (IC1) is installed in an 18-way DIP IC socket. Install this now, with its notch at the bottom end, to indicate the correct orientation when the microcontroller is later plugged in. You can now fit the larger hardware siliconchip.com.au Silicon Chip Binders REAL VALUE AT $12.95 PLUS P & P H SILICON CHIP logo printed in gold-coloured lettering on spine & cover H Buy five and get them postage free! Price: $A12.95 plus $A7.00 p&p per oder. Available only in Australia. Just fill in the handy order form in this issue; or fax (02) 9979 6503; or ring (02) 9979 5644 & quote your credit card number. Your fully-assembled control board for the display unit should look like this. Observe all the usual precautions with component polarity. items, starting with the 26-way DIL header (CON1), the 2.5mm concentric power connector (CON2) and the 2-way terminal block (CON3). Be sure to fit CON1 with its side locating slot towards the left, as shown on Fig.9. Next, fit the AWM608RX data receiver module and the adjacent 4-way DIP switch (S1). Be sure to orientate the latter with the “On” side uppersiliconchip.com.au most, as shown. Assuming you have set the console to channel 1, now is a good time to set this switch to the same setting – ie, set switch 1 in S1 to “On” and set the other three switches to “Off”. This ensures that the transmitter and receiver both operate on the same frequency. LED1, the power/carrier-present LED, is next on the list This goes near the centre of the board and is mounted vertically with its cathode (flat) side facing the receiver module. It’s fitted with its leads left at full length, so that it’s body will pass through a matching hole in the Scoreboard front panel when it’s all finally assembled. Before mounting the LED, fit both leads with 25mm lengths of 3mm varnished cambric sleeving (for insulation and support). That done, the leads can be passed through the board holes and soldered to the pads. As in the control console, a 31mm length of 1mm brass wire is used as an antenna. This antenna is soldered to the centre pad of the AWM608RX data receiver’s antenna terminals. Finally, plug the PIC16F84A-20P microcontroller (programmed with SCORDISP) into its socket, making sure that the notched end faces towards the adjacent 47W resistor. And that’s it – the display control board assembly is now complete and you can start building the four display boards. That’s all we have space for this month. Next month, we’ll describe the display board assembles and give the SC wiring and check-out details. April 2005  77