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Buiding the robot

TSOP hood
         
   

Hood

First prepare the hood for the TSOP1733. Cut it from the black paper along the lines, using a sharp knife and a ruler. Then draw the point of a darning needle along the folding lines to enable sharp folds. Use any paper glue to fix the tabs in place.
   
 
 
PCB top side
   

Dizzy PCB

While the hood dries, Dizzy's PCB can be assembled. Start with the four wire bridges (shown as black lines), using the tinned (not isolated) thin copper wire. Follow with the resistors, the diodes, the two 1uH chokes and the socket for the AT90S2313. Solder each component in place and cut its wires flush with their solder blobs before doing the next one. Double check the resistor values, using an ohmmeter when in doubt (example: 100K can be brown, black, yellow, but brown, black, black, orange is also possible). Note that `220E' in the diagram means `220 ohms'. Note also that the black line on a diode marks the cross line in the symbol. Then push the 8-pin connector in place - first the connecting pins, then, with some force the two plastic stubs.
 
Dizzy PCB  
Do the capacitors, making sure that the polyester 100 nanofarad (larger than the others, and selected to 2% tolerance) is used for the voltage measurement circuit; use the photo above for guidance. Note that colours may differ, pay attention only to value and shape. Follow with the electrolytic capacitors, double checking their polarity; the minus is marked on the case, and corresponds with the `beaker' side of the symbol in the diagram.
Finally add the transistors, the 4MHz resonator and the TSOP1733, taking care to leave its topside 19mm above the PCB. That will make its hood an exact fit, and allows it to look past the opposite motor.
Note: The LDR, its black pipe, the AT90S2313 and the on/off switch should be left until the robot is entirely finished. It is however a good time to make sure that the switch fits; use a small fraise to shape its holes.
 
 
 
 
Side view
   

Motors and wires

Solder the three yellow wires (isolated multistrand) into place as shown below. The motors are originally intended for use in cassette recorders, and are supplied with attached rpm stabilisers, which were removed. Hence their somewhat oddly shaped backsides. Note that one of the connections is close to a small, white stub; that is the plus side. The other one, near to a larger stub, is the minus. Check how the motors fit. You may want to use a file or sandpaper on the PCB to ensure they fit really well. Use either epoxy glue (recommended) or solder to mount them, taking care that the plus connection ends up above the PCB topside, in line with the socket for the AT90S2313. If you choose to solder the motors in position, you need flux and a 50W temperature-controlled soldering iron.
 
    Now connect the motors to their drivers using red wires as shown above, and to their ground pads using blue wires as shown below.  
 
PCB reverse side
 
       

Voice and battery

Cut the piëzo transducer wires down to about 45mm, strip the ends and solder them to the pad and motor pin as shown above. Solder the battery on its pads. Don't push its pins all the way through - that would cause a short circuit! Now glue the piëzo transducer on top (or rather bottom) of the battery, using a small piece of doublesided tape.
Battery close-up        
 
       

Castors

Straighten the 30 cm long piece of silvered copper wire (1.5mm diameter), and cut it in two equal halves. Bend each one in the shape as shown on the right; a `wheel' - diameter about 12mm - as part of a 40mm leg, at right angles to a shaft. The copper wire may seem too easy to bend, but you'll find that it is quite stiff enough to handle Dizzy's 170 grams.
Use for instance a key file to smooth the shaft ends, and fit each shaft with one of the 20mm brass tubes as shown.
Castor        
 
        Castor solder points        

Wheels

Solder the castors onto their pads, as shown on the left. Then bend the castor shaft ends towards the motors, 90 degrees away from the castor legs, referring to the photo below.
Prepare the wheels by sanding the tires until their centerlines are smooth. The motors have a diameter of nearly 32mm, and a 2mm shaft; the wheels are 30mm across. This puts the correct wheel shaft hole position right at the bottom edge of the motors. Bend the silvered wires once again to create shafts there. Fit the wheels and check their positions when touching the motor shafts. Finally bend what's left of the wires towards the feelers to lock the wheels, and cut away the excess wire.
 
        Make sure that the castor hinges and wheels rotate freely. Give the wheel shaft holes a small drop of light oil.
Dizzy will stand on his wheels and the castor on the side of his battery. Bend the castors a little until his circuit board is level in this position, and the other castor is about 5mm off the floor.
Side view
 
       

With feeling

Cut the 40cm steel wire (diameter 0.3mm) in two equal halves. Bend them to fit the PCB as shown on the right. Cut two 12mm long pieces of isolation tubing from a piece of multistrand wire. Also cut one that is about 20mm long. Be sure to remove al metal from the isolation tubing.
Now make sure that everything fits: Push the steel wires through the 17mm brass pipes. Shove a 12mm piece onto each feeler end. Use the 20mm isolation tube to push the smaller pieces all the way through the brass pipes, until a few millimeters are sticking out. Remove the 20mm piece.
Then also remove the 12mm pieces of isolation tubing. (They must not be inside the brass pipes when they are being soldered, as that would melt the plastic.) Solder the feelers in place, together with their brass pipes. Use a little flux to make the steel solder well, clean afterwards. Refit the 12mm pieces of isolation tubing.
 
Finally cut the ends of the feelers to make them 110mm long, measured from the ends of the brass pipes.
Haptic detail
Under the hood        

Finishing Dizzy

Cut a 55mm long piece of black heat-shrinkable tubing, and use a narrow piece of doublesided tape to fit it on top of the 8-pin connector, using the various photos for guidance. Solder the LDR in place (it's a device in a metal case). Note: The tube is needed to make Dizzy's `eye' directional, and also to tune its range. Without the tube, normal daylight would blind the robot.
 
Take a close look at the on/off switch. Make sure that the toggle is in the off position, as shown left, while you solder it in position.
Finally, fit the TSOP1733's hood (there is no need for glue or tape here). The battery is supplied empty, so the robot is not yet ready to wake up. A special procedure must be followed to give it its first charge, prior to fitting the AT90S2313.

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