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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
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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
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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
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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
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