User's Guide
Introduction
Features
Requirements
Controller
Chassis
Assembly
Testing
Troubleshooting
Programming
Contests
Extending
Appendix
Hints
Polarized
Resistors
Capacitors
Servos
Batteries
Datasheets
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Assembling the Mark III
After completing all the above steps, it is time for the final assembly of your Mark III Robot.Controller board to standoffs
The first step in the final assembly is to fasten the Controller board to the standoffs. Position the Controller board so that the serial connector is toward the rear of the chassis. Attach the Controller board to the standoffs using four #4-40 3/8" sheet metal screws. Once again, the screws go into the holes in the end of the standoffs, creating their own threads as they are screwed in. Because the mounting holes on the Controller board are large, you will need to use the four #4 washers provided to keep the screw heads from slipping through the holes. Thread the screws first through the washers, then through the Controller board, and finally into the standoffs, as shown in the picture below.
Now you can finally tighten down all the screws that fasten to the standoffs.
9V placement
The 9V battery which powers the electronics slips in between the rear standoffs and the rear panel.
It is a good idea to put a piece of electrical tape or masking
tape along the top edge of the 9V battery so the metal case of the
battery doesn't short
out the electronics if the battery accidentally comes into contact
with the bottom of the Controller board while the power is on.
If the battery doesn't fit snugly, you can wrap several turns
of tape about the body of the battery to increase its width.
Attaching the Line Sensors
To attach the line sensors, solder the wires directly to the pads on the Controller Board. (If you desire, you may make connectors for the line sensors, but the kit does not include any connectors.) On the Controller Board there are three groups (U5, U6, U7) of four pads, each pad is labeled with the color of the wire that attaches to it, O (orange), G (green), B (blue), and W (white). The left group of four pads, U7, is for the left line sensor, the right group, U5, is for the right sensor, and the center, U6, is for the center sensor. If you insert the wires from the bottom of the circuit board, the wires will be short and out of the way.
A length of 1/8" diameter heat shrink tubing is included in the kit.
This may be used to keep the line sensor wires together in a neat bundle.
At this point in the assembly you will have a good idea of how long
the wires for the line sensors have to be and how they will
be routed to the circuit board. Cut the heat shrink tubing to
length and slip over the wires, shape the bundle
to fit, and use a hair dryer on "high" setting to shrink the tubing.
This may take a while, as many hair dryers are barely hot enough
to cause shrinkage.
GP2D12 cable assembly
The Sharp GP2D12 sensors have an unusual small white header mounted
directly on the sensor. Your Mark III kit has been supplied with the
mating connector. This is an Insulation Displacement connector designed
for use with 26 AWG stranded hook-up wire. Use the excess wire from
your QRB1133 sensors to make small cables for your GP2D12 sensors.
These cables only need be a few inches long - they will have one
connector at each end. To fasten the wire to the IDC connector...
These are Insulation Displacement Connectors - you're supposed
to leave the insulation on. Pushing the 26 AWG stranded wire
into the connector will pierce the insulation at the contact and provide
good mechanical support. The insulation is a large part of the
stress relief/mechanical connection and needs to stay on.
One way to do this is to use a small
blunt-tipped screwdriver and a paper clip end.
If you use a tool that is too sharp it will cut
the insulation, which is bad.
Add heat shrink if desired. fasten wire to other connector, making
sure pin 1 to pin 1 (connectors will be flipped).
GP2D12 placement
To mount your GP2D12 sensors, remove just one of the screws that fastens the scoop to the chassis. Pass the screw through the mounting bracket on the GP2D12, and re-insert through the scoop and chassis. Repeat on other side. JST connector should be pointed to the inside of the robot for both sensors.
Connecting the Servo Motors
The three-pin connectors J3 and J4 at the sides of the Controller Board are for attaching the servos. Just plug them in. As with the line sensors, the proper orientation of the connectors is indicated on the silkscreen with the color of the wires, B (black), R (red), and W (white). Wrap the excess servo wire around the standoffs before plugging in the servo. This will keep the wire out of the way.Calibrating servos (code download!)
Need to calibrate your servos. Use program provided to set zero point.Wheels
The wheels fit directly onto the end of the servos.
Gently press the wheels onto the servo, then use the
mounting screws that come with the servo to attach
the wheel securely.
The wheels need to have "tires" to
provide traction - the tires included with the Mark III
are simply rubber bands. Two sets of tires are provided.
Slip the tires over the rim of the wheel and smooth them out
with your fingers to make them even.
Power
All that's left is to connect the batteries! Power is connected to the board using the three-pin terminal block. There are two power circuits, one for the electronics (regulated) one for the servos. "Standard" configuration is to use a 9V battery for the electronics and 4AA for servos.On the back of the board the terminal block pins are silkscreened "Vin", "V+", and "GND":
- "V+" is the servo power, which comes directly off the 4AA cells. V+ is the terminal nearest to the corner of the board. Wire the red wire from the 4AA battery pack to the V+ terminal.
- "Vin" is the electronics power, which comes off the 9V battery. This is regulated, so you can put in anywhere between 6V and 16V. Vin is the terminal nearest to the standoff mounting hole. Wire the red wire from the 9V battery to the Vin terminal.
- The middle pin is the common ground, labelled "GND" on the back of the board. Connect the black wires from both the 4AA battery pack and the 9V battery to this pin.
