DAGU Playful Puppy User manual

USER GUIDE
Dagu ''Playful Puppy'' Quadruped Robot Kit
Step 1. Center your servos
The QuadBot chassis kit includes 8x miniature servos and the Pan/Tilt kit includes 2 miniature servos.
These servos have clear cases so you should be able to see through them well enough to check that they
are centered.
When the servo is centered it can hysically turn the same amount in each direction (a roximately 90
degrees). Before you begin assembly check that all 10 of your servos are centered. This will save you
time in later ste s. Once the robot is assembled, the center osition of each servo can be refined in the
software if required.
Step 2. Attach the foam rubber feet
Instructions are included with the QuadBot chassis and can also be downloaded from my DAGU
roduct su ort site . I will go through them in detail here.

There are 8 identical leg segments included in the kit. Select 4 of them and attach foam rubber feet
using the 3 x 12mm anhead screws. There are only 4 of these screws and they are the largest so they
are easy to find.
NOTE:
Self ta ing screws have a course thread and ta ered ti that can drill into soft materials like lastic and
wood.
Pan head screws have an extra large head. This is the equivalent of using a se erate washer and screw.
The an head screws in this kit are also self ta ing screws.
Machine screws have a fine thread and are designed to screw into machined arts where a thread is
already resent.
Step 3. Mount nee servos to legs
Mount 4 of your servos on the leg segments with the foam rubber feet. Use 2.3 x 8mm self ta ing
screws.
Make sure the out ut shaft is away from the foot as shown in the hoto.
Step 4. Mount servo horns on the thigh segments
A servo horn is a iece of lastic that fits onto the out ut shaft of the servo and allows you to attach

control rods or other devices using self ta ing screws.
Take the 4 unused leg segments and fit servo horns as shown in the hoto below using 2 x 6mm self
ta ing screws. There are are only 8 of these. Use two for each servo horn.
Step 5. Attach your thigh segment to your legs
Once you have mounted the servo horns on the thigh segments they can be attached to your knee servos
using 4 of the 8 su lied 2 x 8mm an head screws. With your knee servo centered the thighs should
be at 90 degrees to the leg segment with the foam rubber foot.
Step 6. Left and Right legs
So far all of your legs should look identical. Now we will se erate them into left and right legs. The
only difference between a left leg and a right leg is the way in which the thigh servo is mounted.
Mount you thigh servos as shown in the hoto using the 2 x 8mm self ta ing screws. Note the
difference in the osition of the out ut shaft in the left leg thigh servos com ared to the right leg thigh
servos. They are mirror imaged.

Step 7. Attach your legs to the mounting plate
The mounting late of the QuadBot chassis is the laser cut acrylic anel that you mount all your arts
on. Mount your left and right legs as shown in the hoto.
NOTE: the rounded end is the rear of your robot. The hole in the center of the rear is where you will
mount your tail.
Step 8. Fit mounting spacers to pan servo.
The brass hex s acers used to mount the an / tilt kit require a 3mm screw but the miniature servo
housing has a hole designed for a 2mm screw. Previously I have tried using a 3mm drill bit but it bites
into the lastic which can break the servo mounts and it can accidently dig into the servo cable.
Since the hole only needs to be o ened by a small amount I found it was easier and safer to use my
hilli s head screwdriver to ream out the holes on each side. Do not ress to hard, you only need to
ream out each side of the hole by a small amount so that the 3mm screw can be inserted without too
much force.

Once you have the 3mm screw in all the way, continue turning the screw a few times so that the screw
thread can drill out the hole a bit more. You can now easily fit your 25mm (1 inch) brass hex s acers.
Use your liers if necessary to hold the brass s acers when tightening the screws. Do not
overtightenotherwise you will crack the servo mounts.
Step 9. Attach the pan servo to the pan brac et
The an / tilt kit comes with two large brackets. Each bracket has a different hole attern on it to suit
many different sensors. Look at the hoto below and make sure you attach the correct bracket to the
an servo as the com ound eye cannot be mounted if you use the wrong bracket.
The assembly instructions for the an / tilt kit are included in the kit. They can also be downloaded
from my roduct su ort site . Use 2 x 6mm an head servos to mount the bracket to the round servo
horn and another 2 x 6mm an head to mount the servo horn onto the an servo as shown.
Step 10. Attach the tilt servo locating brac et
The tilt servo locating bracket doesn't actually hold the tilt servo in lace. It's main ur ose is to
revent the tilt servo from twisting while allowing some lay so the servo can self center.

This bracket is mounted using two 3 x 6mm machine thread screws and two 3mm nuts. Leave these
nuts slightly loose at this stage so that the bracket can move forwards and backwards slightly. We will
tighten them once the servo is aligned.
Step 11. Attach the servo horn to the tilt brac et
Use two 2 x 6mm an head screws to attach a round servo horn to the tilt bracket. Use holes that will
allow the center hole of the servo horn to align with the bracket as shown without allowing too much
lay if the screws come loose.
Step 12. Align the tilt servo
Use a 2.3 x 12mm screw to align your tilt servo. The servo will be a firm fit in the tilt servo locating
bracket. Adjust the osition so that the servo alignes with the an bracket and allow room for s acer
washers and a servo horn. Once everything is aligned you can tighten the 3mm screws holding the tilt
servo locating bracket so that it wont move.

Step 13. Inserting the spacer washers
There are some s acer washers that must be inserted so that the tilt assembly can rotate smoothly. The
easiest way I know to insert these s acer washers is to lie the an / tilt assembly on it's side with the tilt
bracket at about 40 degrees when the tilt servo is centered as shown in the first hoto.
Stack your s acer washers neatly and insert them as best you can with your hand or long nose liers as
shown in the second hoto.
Use a lastic cable tie to gently ush the washers into osition as shown in the third hoto. Once the
holes line u it's easy to insert your 2.3 x 10mm screw through the brackets and washers into the servo
out ut shaft.
Tighten all the way being careful not to overtighten and then back off 1/4 of a turn. The tilt bracket
should be able to tilt u and down fairly easily. Loosen the screw a little more if required.
Do the same on the other side with the 3 x 10mm machine screw and nylon nut on the other side.
NOTE: The nylon nut should be slightly loose so that the tilt assembly can move easily.
Step 14. Mount the eye

The IR com ound eye is a sim le sensor that measures ambient light and reflected IR light from an
object. The eye has seven connectors. Vcc (+5V) and Ground for ower. The ENable in turns the IR
LEDs on or off and then there are 4 analog out uts for u , down, left and right.
Attach the four mounting s acers on the tilt bracket as shown in the first hoto. Make sure the 3mm
nuts are tight.
Connect 80mm female to female jum er wires to the eye as shown in the second hoto. I've used red
for Vcc (+5V), black for ground (0V), orange for the enable in and white for the 4 analog out uts.
Because 80mm is not long enough I have then attached 80mm male to male jum er wires. This gives
me 160mm female to male jum er wires as shown in the third hoto.
By runing the wires under the tilt bracket and then over the tilt servo as shown I find the head can move
freely in any direction without ulling on the wires.
Step 15. Mount the head onto the body
Use two 3 x 10mm an head machine screws to mount the head. Notice the holes used in the first
hoto. The servo is mounted slightly toone side so that the an servo's out ut shaft is centered rather
than the servo body. The an servo is mounted a reasonable distance back to im rove the ballance of
the robot and to hel rotect the an servo if the robot runs into a wall.
Step 16. Mount your batteries

This robot works best with a small LiPo battery (7.4V, 2300mAH) but rechargeable AA NiMh batteries
are more common and easier to recharge so we will use 6x AA NiMh batteries for these instructions.
Do not use alkaline batteries, the voltage is too high and they cannot ut out enough current to drive the
servos. This will cause your rocessor to continually reset. Use good quality batteries with at least
2000mAH ca acity.
2 x 3 cell battery holders are fairly common and are small enough to fit between the legs of the robot.
Place some ta e on the ends of the wires before you starts so that they can't short out before you are
ready to connect them and then install 6x fully charged batteries.
Cable tie your battery holder to the center of the mounting late with your wires on the right hand side.
Make sure all legs can move inward about 45 degrees without hitting it. Do not make the cable ties too
tight ! You should be able to just slide the battery holder sideways out of the cable ties when it is time
to recharge the batteries.
Step 17. Mount the Magician robot controller
Attach the four su lied brass s acers to the corners of the controller PCB. Now mount the board on
the chassis with the ower connection on the right hand side and the analog ins closest to the head as
shown in the second hoto.

Step 18. Wire up the head
Connect your an servo to A4 and your tilt servo to A5 with the white signal wire towards the female
header. The software reconfigures these ins as servo out uts.
Fit small black and red female to female jum er wires to Vcc and ground as shown in the hoto. These
will rovide ower for the infrared com ound eye. Check the third hoto if your not certain where to
connect something or download the manual from my su ort site . Connect the red and black ower
wires from the eye.
The motor control circuitry connects to the rocessor via 4 jum ers. remove the jum ers on D8 and
D10. Leave the jum ers on D7 and D9. This allows us to use D8 to control the IR LEDs on the eye.
D10 might be used to control a small s eaker or LED. The left motor control circuit is still connected
and can be used to drive a small shaker motor to make the tail wag.
Connect your orange jum er wire to D8 and connect your 4 analog out uts from your eye.
A0 is u .
A1 is left.
A2 is down.
A3 is right.
Step 19. Power configuration

The ower configuration for this robot is slightly unusual.
10 miniature servos combined can draw more than 3am s when the robot is running around. This is far
more than the Magician's regulator can handle. The magician board does allow you to ower u to 8
servos directly from the battery but the servos are rated at 6V and the battery is 7.2V!
To solve these roblems, the an and tilt servos which are not heavily loaded are run from analog ins
4 and 5. These ins have been converted to servo out uts in the software and have ower su lied by
the 5V regulator (normally used for sensors). This leaves the 8 leg servos to be owered directly from
the battery.
What we do here is to use diodes to dro the voltage to a safe level. Most silicon diodes have a forward
voltage dro of about 0.6V regardless of the current. The Magician controller already has a 3A diode in
series with the battery to rotect against accidently connecting the ower around the wrong way.
This diode will dro the voltage by about 0.6V. By adding a second diode in lace of the jum er that
selects the servo ower we effectively have two 3A diodes in series with the battery that is reducing the
voltage to the servos by a total of 1.2V. Our leg servos are now getting the 6V they are rated for.
The leads on a 3A diode are slightly thicker that a male header in. bend the leads close to the body of
the diode as shown and fit two small female to female jim er wires. they will be a tight fit but this is
good as it ensures a good electrical connection. Fit a red wire to the anode and a black wire to the
cathode.
Now remove the servo ower selection jum er and fit the diode instead. Attach the red wire to VBAT
and the black wire to the center in. The servos will now receive ower through this diode. If you
accidentally connect the diode the wrong way around then the servos will not get ower but no damage
will be done.
NOTE: If you want your robot to stand on it's hind legs with NiMh batteries then you may need to
leave the diode out and use the original jum er. This will give your servos 6.6V and more ower. You
will increase your risk of damaging the servos slightly if you do this.
Step 20. Connect the leg servos

Start by fitting the servo extension cables to the front leg servos. Now lug in your leg servos.
D2 - Rear left hi
D3 - Rear left knee
D4 - Front left hi
D5 - Front left knee
D6 - Front right knee
D11 - Front right hi
D12 - Rear right knee
D13 - Rear right hi
Make sure your white / orange control wire is closest to the female header.
Step 21. Connect your batteries.
Make sure the ower switch is in the off osition and then remove the ta e from your black (- negative)
wire. stri the wire back, twist the strands together and then bend it over before inserting into the screw
terminal as shown in the hoto. This will hel to ensure a good connection. Now remove the ta e on
the red wire (+ ositive) and do the same.
Step 22. Add a tail

Perha s the easiest way to make a tail is to use a short length of s iral wra . If you don't have s iral
wra then you can make some by feeding a drinking straw through a encil shar ener. The encil
shar ener will robably need a new blade as it has to be shar .
Plug one end with some hotglue or utty. Then use a self ta ing screw to mount it at the back of the
chassis as shown in the second hoto. If you can get hold of a small shaker motor from an old mobile
hone then mount it on the tail and connect it to the left motor out ut. The sam le code will shake the
tail harder as your hand gets closer.
Step 23. Installing the software
To install the sam le code you must first have the Arduino IDE version 18 or later running on your
com uter. Download here .
The Magician controller uses the CP2102 interface IC. De ending on your OS you may need to install
drivers. You can download the USB drivers as well as the QuadBot Pu y rogram from my su ort
site .
Once you have the Arduino IDE running, you can o en the rogram. Make sure you have the version
suited to the batteries you are using so that the robot will be able to stand on it's hind legs. You will see
that the code has a constants tab and an IO ins tab.
The constants tab stores values such as the center ositions of servos. This makes it quick and easy to
fine tune your code. The IO ins tab is like a ma for your wiring. It tells you which device is connected
to what in.
Go to the tools menu and select your board ty e. The Magician controller is com atible with "Arduino
NG or older /w ATmega8"
Now lug in your USB cable. After a few seconds your com uter should detect the USB interface of
the Magician controller. Go back to the tools menu and select your USB virtual serial ort.
Press the reset button on the controller and u load the rogram.
Step 24. Controlling your robot

The sam le code tracks your hand movements with the com ound eye and res onds accordingly. If you
leave the robot alone for 3 seconds then it will sit down out of boredom. Once it sits down it gets lazy
and will only track your hand with it's head.
If you slowly bring your hand within range and move your hand to a aw then the robot will lift that
aw for you to shake hands. If you bring your hand between the aws it will lie down.
Once sitting you must excite the robot to get it to stand back on it's feet. taking your hand to one side or
above the robot so it can no longer see your hand will do this.
When the robot is standing it will try and maintain a set distance from your hand. It will walk forward,
move backward or turn in order to kee your hand in range. Do not move your hand too quick or it may
loose sight of your hand.
If you move your hand directly over it's head while the robot is standing then it will try to jum on it's
rear legs. If your hand stays in range of the eye the robot will try and walk on it's back legs to follow
your hand. This trick might not work with the NiMh batteries as they are heavier than the LiPo battery
used in the demo video.
Step 25. Trouble shooting
The robot robably won't work very well at first. Each servo is a little bit different so some tweaking is
required. At the start of the main loo add the line "return;". This will cause the robot to stand still
indefinitely.
You can now adjust the servo center ositions in the constants tab until the rear hi s are at 90 degrees
to the body and the front hi s are slightly forward. All knees should bend inward slightly. If any of your
servos are drastically out of alignment then you may need to reseat the servo horn.
Your head should look straight forward with the head looking u at about a 30 - 40 degree angle. Once
your robots servos are set correctly you can remove the "return;" line from your main loo .
If the head does not track your hand then check your eye connections. If the head turns away from your
hand then you may have accidently swa ed your wires or mounted the eye u side down (the wires
should come out at the bottom). Double check everything in ste s 14 and 18. Are your servos lugged

in corectly?
If the robot frequently resets then you may have a bad battery or battery connection. Check your
batteries have a good charge and are making a good connection with the battery holder terminals. Are
the battery terminal screws tight? Some chea batteries may not be able to deliver enough current.
If the head does not follow at all then check your eye has ower (5V) and that the orange wire is
connected to D8. Double check everything in ste s 14 and 18.
If the head works but the legs don't move then your diode that re laced the servo ower jum er in ste
19 may be around the wrong way or not lugged into the correct ins. Check ste 20 to make sure you
have the servos lugged in correctly with the signal wire closest to the female header.
If the robot walks funny then you may have accidently swa ed hi and knee servos. The hi servo
allows the leg to move forward and backward. The knee servo allows the leg to move u and down.
If the robot cannot stand on it's hind legs then check you have the correct version of the code. NiMh
batteries are heavier than LiPo batteries. This affects the robots ballance. You may need to lay with the
code or adjust the osition of your batteries a bit.
If you are Using NiMh then you will robably need to remove the voltage dro diode and re-install the
voltage selection jum er for the servo ower. This will run your servos at 6.6V giving them more
ower but there is a greater chance of the servo stri ing a gear or overheating.
Step 26. Give your puppy some personality!
The Sam le code is just the beginning. Ex eriment with it! If you make a mess of it you can always
download the original code and start again.
Moods such as ha y and bored are easily rogrammed into the robot. Use a counter to determine
ha iness by how much a erson lays with it. When they sto laying then the counter counts down.
Boredom sets in when you don't lay with it for a short while. Perha s your robot will be naughty if it
becomes too bored?