Kitronik PIC Frisbee User manual

PIC Frisbee
Build Instructions
Issue 1.1

PIC Frisbee
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Build Instructions
Before you put any components in the board or pick up the soldering iron, just take a look at the
Printed Circuit Board (PCB). The components go in the side with the writing on and the solder goes on
the side with the tracks and silver pads. You will find it easiest to start with the small components and
work up to the taller larger ones. If you’ve not soldered before get your soldering checked after you
have done the first few joints.
Step 1
Start with the six small resistors (shown right):
R1& R2 are 10KΩ(Brown, Black, Orange coloured bands).
R3 is a 22KΩ(Red, Red, Orange coloured bands).
R4, R5 & R6 are 330Ω(Orange, Orange, Brown coloured bands).
The text on the board shows where R1, R2, etc go. Make sure that you put the
resistors in the right place.
Step 2
Solder the Integrated Circuit (IC) holder (shown left) in to IC1. When putting this into the
board, be sure to get it the right way around. The notch on the IC holder should line up
with the notch on the lines marked on the PCB.
Step 3
Solder the programming connector (shown right) into the board where it is labeled
‘PROG’.
Step 4
The two tilt switches (shown left) should be soldered into the PCB where it is
labeled SW1 and SW2. Make sure these are inserted the correct way around,
which is indicated by the outline on the PCB.
Step 5
The two battery holders (shown right) should be soldered into the PCB where it is
labeled BAT1 and BAT2. Make sure these are inserted the correct way around,
which is indicated by the outline on the PCB.
Step 6
Solder the electrolytic capacitor (shown left) into the board where it is labeled C1. Make
sure the device is the correct way around. The capacitor has a ‘-’ sign marked on it which
should match the same markings on the PCB.
Step 7
There are three LEDs that are used in the circuit (shown right). These are to be soldered
in to the PCB where it is marked LED1, LED2 and LED3. It doesn’t matter which
coloured LED goes where but it is important that they are inserted the correct way
around. Again this is indicated by the outline on the PCB. The flat edge on the outline
should match the flat on the body of the LED. You may want to stand these LEDs off
the PCB so they are higher than the other components.
Step 8
The PIC can be put into the holder ensuring the notch on the chip lines up with the notch on the
holder. Step 9 (optional)
The buzzer (shown left) should be soldered into the ‘SOUNDER’ terminal. The red wire
should go to the terminal marked ‘red’ and the black wire should go to the terminal
marked ‘black’.

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Checking Your PCB
Check the following before you insert the batteries:
Check the bottom of the board to ensure that:
•All the pads with wires in them are properly soldered.
•Pins next to each other are not soldered together.
Check the top of the board to ensure that:
•The notch on the IC and the IC holder are is next to the text ‘IC1’.
•R1& R2 have brown, black and orange coloured bands.
•R3 has red, red and orange coloured bands.
•The negative ‘-’ markings on the capacitor match the same markings on the PCB.
•The battery holders are in the same orientation as the outlines on the PCB.
•The tilt switches are in the same orientation as the outlines on the PCB.
•The flat edges of the LEDs match the outlines on the PCB.
Testing the PCB
The circuit has been designed to allow easy testing of the PCB. To test the PCB you will first have to
insert a chip programmed with some software to allow it to be tested. The purpose of the test
program is to test that the LEDs work, the buzzer can sound (if fitted) and that the switches are
functioning (used to turn the LED and buzzer patterns on and off). The test software works as shown
below.
If you have problems with any of the above use the fault finding flow chart to find the cause of the
fault. Please note that these fault finding diagrams have been based around using the test software
outlined above. If you are using an alternative test program they will not be suitable.
Yes No
Start
LED1 on for 1 second
Is the Frisbee
spinning?
LED2 on for 1 second
LED3 on for 1 second
All LEDs off
Sound a note (if
buzzer fitted)
All LEDs off
Wait for 5 seconds
All LEDs on

PIC Frisbee
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Fault Finding Flowchart
Start
DoLEDs
1, 2, 3 light in turn
(and at the right
brightness)?
No
(if fitted)does
the buzzer sound
aftertheLEDs?
Yes
Are all the
LEDs now off?
Check
• IC1 pin 2 for a dry joint
• The sounder connections for
dry joints
There is a dry
joint on R1
Do theLEDs
turn on when spun
a 2
nd
time?
Yes
No, they all stay off
Check
• IC1 pin 4 for a dry joint
• SW1 & SW2 for dry joints
No
Stop
Yes
Go to page 2
Yes
No, all the LEDs are on
Do all the
LEDslight whenthe
board is spun?
No,thepattern restarts
Yes There is a dry joint on
IC1 pin 8
No,thepattern restarts
There is a dry short on
IC1 between pins 3 & 4
Arethere
any other issue?
No
Yes,it wont program Yes,the pattern restarts
when knocked
Check
• IC1 pin2 for a dry joint or
short to pin 1
• Allpins on the programming
connector for dry joints
• R2 is 10K and R3 is 22K
There is a dry
joint on C1

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No
Which LED is dim?
LED1 – R4 is the wrong value
LED2 – R5 is the wrong value
LED3 – R6 is the wrong value
R4 – R6 should be 330Ω
(orange, orange, red)
Check
• BAT1 & BAT2 are in the
right way (the ‘+’is visible)
• The batteries are good
• IC1 pin 1 for a dry joint
• C1 for a short
No
Yes, but looking carefully
it is just very dim
Did any
LEDs light?
Isjust one
LED missing from
the pattern?
Yes
Which LED is missing?
LED1 (check the following)
• LED1 for a short, dry joint and that its in
the right way around
• IC1 pin7 for a dry joint or short with pin 8
• R4 for a dry joint
LED2 (check the following)
• LED2 for a short, dry joint and that its in
the right way around
• IC1 pin6 for a dry joint or short with pin 5
• R5 for a dry joint
LED3 (check the following)
• LED3 for a short, dry joint and that its in
the right way around
• IC1 pin 3 for a dry joint
• R6 for a dry joint
Yes
Frompage1
Which bold text best describes the LED?
Only LED3 lights
• There is a short on IC1 between pins 6 & 7
LED1 flasheson & off
• There is a dry joint on either R2 or R3
TheLEDsflashLED3,gap, LED1
• The test chip (IC1) is in the wrong way
around
AsLED3 turns on LED1 briefly goes on
and then the pattern repeats
• There is a short on IC1 between pins 2 & 3
Fault finding flowchart
page 2

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Programming Tasks
Here are the PIC connections for reference when writing your software.
Input / Output Pin Connected to
Input Pin 4, GPIO3 Tilt switches
Output Pin 3, GPIO4 LED 3
Output Pin 6, GPIO1 LED 2
Output Pin 7, GPIO0 LED 1
Output Pin 5, GPIO2 Sounder
Simple task overview
Programming task – Turn LEDs on in a pattern when the Frisbee is spun
When the Frisbee spins and the switches are closed, the input pin goes to a high voltage. When this
happens turn the LEDs on to produce a visual pattern. If you have connected a buzzer then a tune
can be played at the same time. When the Frisbee stops spinning the LEDs and buzzer should be
turned off.
Advanced task overview
Programming task – In addition to the functionality in the simple task above use the sleep function to
increase the products battery life
The circuit normally uses 0.9mA of current while it is waiting to see if the switches have closed. This will
give a battery life of around 2 weeks.
If the sleep function (this turns off a lot of the functions within the PIC for around 2 seconds) is used it is
possible to get the current the circuit uses down to around 0.140mA. This will mean the battery life will
increase to about 3 months.
To do this you will need to add the following operations to your software program:
•If the Frisbee hasn’t been spun for 30 seconds then go to sleep. This can be done by adding a
short 0.2 second delay where the switch is checked and keeping a count of how many times
this delay has run. If 30 seconds passes and the count has reached 150 then go to sleep.
When a spin is detected the count should be set to zero.
•When the PIC periodically finishes the sleep function check the switch input.
oIf the Frisbee is not being spun call the sleep function again.
oIf the Frisbee is being spun the start the LED pattern (and tune), then stay awake until
the Frisbee hasn’t again been spun for 30 seconds, at which point call the sleep
function again.

PIC Frisbee
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How the Frisbee Hardware Works
The Frisbee is based around an eight pin PIC microcontroller device. A PIC is in effect a small
computer that behaves in a way determined by the software it’s programmed with. This software is
generated by the user / student. It is this code that will determine the eventual function of the project.
To aid the design of this software the following describes the function of the hardware (circuit) that
this software controls. From the Frisbee circuit above you can see that the PIC has one usable input
and four usable outputs.
Input / Output Pin Connected to
Input Pin 4, GPIO3 Tilt switches
Output Pin 3, GPIO4 LED3
Output Pin 6, GPIO1 LED2
Output Pin 7, GPIO0 LED1
Output Pin 5, GPIO2 Sounder
The other connections to the PIC are to provide it with power (V+ = pin 1 and Gnd = pin 8) and also
allow it to be programmed with the user defined software (Pins 2 and 7). When pin 7 is not being used
to program the device it is used as the output which controls LED1.
The input is connected to the two tilt switches and a resistor. When either or both of these switches are
open the 10K resistor pulls the voltage on the input to the PIC to a low voltage. When these switches
are both closed the voltage on the PIC pin is pulled up to a high voltage. The software is able to read
this change of state. These switches are both closed when the board is spun. This is because the
centrifugal force pushes both of the elements in the tilt switches outwards. If it is not spinning only one
of these switches at a time will be closed because of the way they are orientated (opposite to each
other).

PIC Frisbee
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Three of the outputs have been connected to LEDs. Between each of the PIC outputs and each of
the LEDs is a resistor. The purpose of these resistors is to limit (restrict) the flow of current into the LEDs.
This controls the brightness of the LED and prevents it from becoming damaged, which would
happen if no resistor was used. A 330Ωresistor has been used for this purpose.
The circuit has been designed so that a buzzer can be added. The type of buzzer used should not
have any drive circuitry. This means that it needs driving with square wave (alternating high low
voltage signal) to make it produce a tone. The frequency of the tone will be the same as that of the
square wave that is used to drive it. It is by varying this tone that the sounder can be used to play a
musical tune.
One other point worth noting is the processor clock. For any micro-controller to work it requires a clock
source. The micro-controller uses this clock so that it knows when to execute the next line of software.
Often these clocks are generated externally but in the chip used in this circuit the clock is built into the
chip itself. This is why it does not appear on the circuit diagram.
Why use a PIC micro-controller?
There are a number of advantages of using a micro-controller; some of these are outlined below:
•Complex functionality can be produced a very low cost.
•Circuit size can be very small for and still provide complex functionality.
•It is very easy to make minor alterations to the function of the product.
oFor instance changing the tune that is played.
•Flexibility. The circuit could easily be used for a completely different function by simply re-
writing the software.
•Easy to develop and debug. Most software packages allow you to simulate the software while
it is being developed making it much more likely to work when used. It is also possible to break
the functionality down into small steps which is easier to get right then jumping straight to the
final design.