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Enhanced Sports Scoreboard Here’s an upgraded version of the Professional Sports Scoreboard described earlier this year. In particular, it now provides a 2-digit “Fouls” display for each team, as well as the original displays for the Home and Away scores, Time Remaining and Current Period. 82  Silicon Chip By JIM ROWE I F YOU READ the articles in our March-May 2005 issues on the Jaycar Sports Scoreboard project, you’ll know that even before we finished describing it, we were prompted to add netball scoring to its original basketball code capabilities. That was done simply by upgrading the controller firmware, so it would set the board up siliconchip.com.au siliconchip.com.au August 2005  83 Fig.1: this is the revised scoreboard controller circuit. The main change involves the added 16-way ribbon cable connector (CON4) for the Fouls displays. This connects to four previously spare outputs on digit decoders IC2 and IC3, to provide the drive signals for the four extra digits. Fig.2: the Scoreboard Display 2 (Home/Away Fouls) board is driven via CON4 on the controller board and uses 56 10mm yellow LEDs to form two complete 7-segment digits. for netball in response to an extra setup code from the console (ie, no changes were required to the hardware of either the scoreboard or the console). Subsequently, as soon as the third article had been published, we started to get requests for even more features. 84  Silicon Chip The most common of these requests was for the addition of basketball “Fouls” displays – one for each of the two teams (and preferably each display having two digits for a count of 0-99). In the end, it became clear that we were going to have to upgrade the design to add this feature at the very least. While we were at it, we decided to make a few other changes as well. In particular, the display brightness has been improved, while the firmware has been upgraded to provide improved timing accuracy. The wireless Consiliconchip.com.au trol Console is virtually unchanged, though – only the front panel art has been changed, to re-label keys that have changed in function. This means that if you have an existing control console, it can be used as is. Adding the fouls displays Unfortunately, the two extra fouls displays couldn’t be added to the original design by simply making a few changes to the firmware. There were some unused outputs available from the digit decoder ICs but no spare conductors in the original ribbon cable linking the display boards to the controller board, to drive any additional displays. The only real option was to modify the controller board and add a connector for a second ribbon cable, to drive the two additional display boards. It was quite a challenge to fit this extra cable connector (a 16-way DIL socket) plus its segment drive resistors and other circuitry but, in the end, this was done without changing the overall size of the board. Of course, it was also necessary to come up with an additional display board design, for the new Fouls displays. This was adapted from the original team score board design, with the same system of allowing it to be made in two versions (Home Fouls and Away Fouls) simply by fitting the digit drive input resistors in two different positions. The new Fouls display boards provide two 130mm-high digits (like the other displays), each formed using 28 10mm-diameter yellow LEDs. This was done so that they could be added to the original Scoreboard with as little complication as possible. The new displays mount behind additional cutouts at the lower corners of the board, below the team score displays. Note that this can be done even with existing boards, as the “end of period” siren is moved over to a position midway between the Game Period and Away Fouls displays. While the controller board was being modified to drive the additional display boards, we also took the opportunity to make a few other modifications which enhance performance. For example, the power supply circuitry has been changed so that the Scoreboard can now be powered from a regulated 15V plugpack, for even siliconchip.com.au Par t s Lis t – Sports Scoreboard Additional Cables & Sockets 3 16-way IDC line sockets (Jaycar PS-0985) 1 900mm length of 16-way IDC ribbon cable Revised Controller Board 1 PC board, code BSBCONTE, 127 x 190mm 1 2.4GHz AV Receiver module, AWM608RX (Jaycar QC3592) 1 31mm length of 1mm-dia brass wire 1 TO-220 heatsink, 6021 type 1 4-way DIP switch (S1) 1 10MHz crystal (X1) 1 PC-mount 26-way DIL socket (CON1) 1 PC-mount 16-way DIL socket (CON4) 1 PC-mount 2.5mm concentric DC socket (CON2) 1 2-way PC-mount terminal block (CON3) 1 18-pin DIL IC socket, machine pins 13 M3 x 6mm machine screws, round head 4 M3 x 25mm tapped metal spacers 4 M3 x 15mm machine screws, csk head 9 M3 nuts and star lockwashers 1 15V DC 1.5A regulated plugpack supply (Jaycar MP-3423) 1 length of 0.5mm tinned copper wire for links Semiconductors 1 PIC16F84A-20P microcontroller programmed with SCORDISP2.HEX (IC1) 2 4028B CMOS decoders (IC2, IC3) 1 74HC08 quad NAND gate (IC4) 1 74HC74 dual D-type flipflop (IC5) 4 PN100 NPN transistors (Q1,Q9, Q10,Q12) higher display brightness. In addition, the board earthing has been modified to reduce the risk of interference to the PIC controller (IC1) and the digit decoders (IC2, IC3), due to the high current pulses through display segment driver transistors Q2-Q8. 8 MTP3055 power MOSFETs (Q2-Q8,Q13) 1 PN200 PNP transistor (Q11) 1 7805 +5V regulator (REG1) 1 5mm red LED (LED1) 6 1N4004 1A diodes (D1-D6) 4 1N4148 signal diodes (D7-D10) Capacitors 1 2200mF 16V RB electrolytic 1 100mF 16V RB electrolytic 2 10mF 16V tantalum 3 4.7mF 16V tantalum 5 100nF multilayer monolithic 1 100nF MKT metallised polyester 2 33pF NPO disc ceramic Resistors (0.25W 1%) 1 100kW 1 4.7kW 2 47kW 1 470W 1 22kW 8 47W 6 10kW 14 10W Fouls Display Board (x 2) 1 PC board, code BSB-D2, 180 x 190mm 1 PC-mount 16-way DIL socket (CON1) 8 6mm x M3 machine screw, round head 6 25mm x M3 tapped metal spacer 6 15mm x M3 machine screw, csk head 2 M3 nuts and star lockwashers 1 length of 0.5mm tinned copper wire for links Semiconductors 2 PN100 NPN transistors (Q1,Q2) 2 BD136 PNP transistors (Q3,Q4) 56 yellow 10mm LEDs, high brightness or standard Capacitors 1 1000mF 16V RB electrolytic Resistors (0.25W 1%) 4 4.7kW 2 120W Naturally, the scoreboard controller firmware also had to be extensively revised in order to drive the additional Fouls displays and to allow them to be updated (incremented or decremented) from the Control Console. Finally, we also took the opportunity August 2005  85 Console. This was achieved by simply re-allocating the original “+3” and “+2” score buttons for each team, so that they now perform the “Fouls +1” and “Fouls -1” functions. In practice, they still send the original control codes to the scoreboard controller but the latter now interprets them to carry out the new functions. As a result, the only modification that has been made to the Control Console is a change in the front panel artwork, to show the new button functions. This change in the console button functions does mean that in order to add two or three points to the score of either team, you now have to press their ‘Score +1’ button two or three times in succession rather than simply pressing the original ‘+2’ or ‘+3’ buttons once. However we believe users won’t mind having to make a few more button presses, in order to have the added Fouls facility with a minimum of cost and complexity. Circuit details Fig.3: this is the parts layout for the revised controller board. Make sure that all polarised parts go in the right way around. to improve the controller’s timing accuracy by making the timing function independent of the number of console commands that have to be processed. This now gives the scoreboard a timing accuracy of better than 0.04% and also provides a spin off benefit: there is now virtually no display blinking when the 86  Silicon Chip controller is processing commands from the console. Control console As mentioned above, all these enhancements have been made without making any changes to the circuitry or firmware in the wireless Control Fig.1 shows the revised scoreboard controller circuit. As shown, the additional 16-way ribbon cable connector for the Fouls displays is CON4 and this is located just to the right of the original 26-way display connector (CON1). It connects to four previously spare outputs on digit decoders IC2 and IC3, to provide the drive signals for the four extra digits. These are digits D13 and D14 on the Home Fouls board and D15 and D16 on the Away Fouls board. The new display boards also need the 7-segment drive lines and these are derived from segment driver transistors Q2-Q8 via a second set of 10W current limiting resistors. The only other connections needed are for 14.4V power and ground. These both use multiple ribbon conductors to improve current carrying capacity and to also provide a measure of shielding. The only other change to the controller circuit is the addition of three 1A power diodes (D4-D6) in series with the input to +5V regulator REG1. These drop a further 2V or so, allowing the controller to be powered from a 15V DC regulated plugpack (for improved display brightness), while preventing REG1 from overheating due to excessive voltage drop. Fig.2 shows the circuit for the new Fouls display board. It’s basically just a simplified version of the original siliconchip.com.au Team Score board circuit. However, in this case, there are only two digit drivers, using transistor pairs Q1-Q3 and Q2-Q4 respectively. When the board is used as the Home Fouls display, the two 4.7kW driver input resistors are connected to pins 9 and 7 of the 16-way DIL connector CON1, so that the digits become D13 and D14. Conversely, when the board is used as the Away Fouls display, the resistors are connected to pins 3 and 1 of the connector instead, so the digits become D15 and D16. As mentioned earlier, the digits themselves are formed using 28 x 10mm-diameter yellow LEDs, with four LEDs per display segment. Construction details Fig.3 shows the parts layout for the new controller board. All of the original components are used and most are located in either exactly the same position or moved just a short distance to make space for the added components. This board is wired in exactly the same way as the original, apart from having an additional 16-way DIL connector, a few more wire links and some extra resistors and diodes to fit. Fig.4 shows how to wire up the two new Fouls display boards. This mainly involves fitting 56 large yellow LEDs to each board. Note that these all fit with their longer anode lead towards the top of the board, so the job is easily done once you get into the swing of it. That done, you can fit the six wire links, connector (CON1), the four transistors and the resistors and capacitors. Note that the locations of the two 4.7kW resistors adjacent to CON1 vary, depending on whether you’re building the Home Fouls display or the Away Fouls display. Finally, follow Fig.5 to connect Your completed controller board should look like this. It’s now powered from a 15V DC plugpack, for even greater brightness from the LED displays. the two Fouls display boards to the controller board. This is done using a 900mm-long 16-way ribbon cable fitted with three IDC line sockets. as the original version. For example, the Scoreboard should have power applied first and then power applied to the console after about 10-20 seconds. This is necessary because when the console is powered up, it sends a code to set up the Scoreboard for the game Revised operation In most respects, the upgraded Scoreboard operates the same way Table 1: Resistor Colour Codes o o o o o o o o o o siliconchip.com.au No. 1 2 1 6 5 1 2 8 14 Value 100kW 47kW 22kW 10kW 4.7kW 470W 120W 47W 10W 4-Band Code (1%) brown black yellow brown yellow violet orange brown red red orange brown brown black orange brown yellow violet red brown yellow violet brown brown brown red brown brown yellow violet black brown brown black black brown 5-Band Code (1%) brown black black orange brown yellow violet black red brown red red black red brown brown black black red brown yellow violet black brown brown yellow violet black black brown brown red black black brown yellow violet black gold brown brown black black gold brown August 2005  87 Table 1: here’s how to set the console DIP switches for the various games. Fig.4: here’s how to build the Fouls display board. Note that two slightly different versions must be built – one with the two 4.7kW resistors at top left in the “Home Fouls” position and one with the resistors in the “Away Fouls” position. Note: PC overlay shown 64% of actual size. 88  Silicon Chip you want to play (as set by the console’s internal DIP switches). The short delay is needed to make sure that the Scoreboard controller and its 2.4GHz receiver are fully operational before the console sends the game code. The accompanying table (Table 1) shows how to set the console DIP switches for the various games. To reset the Scoreboard ready for a new game, you press the two red Reset buttons on the console simultaneously and then press them both again. This “press them both together twice” procedure is designed to prevent you from accidentally resetting the board in the middle of a game. To start a new game period, you press the green “Start Next Game Period” button. This starts the countdown clock and as the time passes, the time remaining in that period is continuously displayed at the top of the scoreboard. The Game Period display shows the current period: “1”, “2”, “3” and so on. If you subsequently press the “Start Next Game Period” button after the last normal period has ended, the Game Period display will show “E” (for extra time) and the clock will count down from 5:00 minutes (the standard extra time period duration). During any game period, if a “time out” is called, you can stop the Scoreboard’s clock by pressing the white “Stop Clock” button. Then, when play resumes, you press the Blue “Restart Clock” button to set it going again. During play, you can increment the score of either team by pressing the relevant grey “Score +1” button. To increase the score by two or three, you simply press that button two or three times (not too rapidly, or the extra points won’t be registered). If a mistake is made and the score needs to be reduced, you just press the black siliconchip.com.au Fig.5: the fouls display boards are connected to the controller board using a 16-way ribbon cable fitted with three IDC line sockets. Be sure to position the red cable edge stripe as shown. “Score -1” button for that team. Fouls are registered in exactly in the same way, except that you use the yellow “Fouls +1” or white “Fouls -1” buttons. Note that while the team scores are maintained through all of the game periods, the fouls are cleared at the start of each new game period. The only exception to this is at the start of an “Extra Time” period, where the fouls registered for the last normal game period are maintained. As before the Scoreboard’s countdown clock displays minutes and seconds during most of each game period but automatically switches over to seconds and tenths of a second during the final minute of play. Finally, at the end of this period, the siren sounds for two seconds to signal SC the end of play. siliconchip.com.au The Control Console has a new front panel label to re-assign some of the switch functions. Apart from that, it’s unchanged. August 2005  89