Technical Topics for Teams

Technical Topicsfor Teams

August 2010

BEST GAME RULES

SAFETY FIRST

Safety glasses (Team supplied)

Hearing protection “Dust mask “Buddy systemKeep work area cleanSupervise students at all times

Read your power tools owner’s manual

Use only the parts supplied in the Returnables and Consumables kits to build the robot

Items that are purely decorative such as paint, lights, decals, etc, may be applied to the robot, but not to Return Kit parts

The robot must fit into a two foot cube and cannot weigh over 24 pounds. The robot may expand after it exits the start box

You must use the supplied batteries and chargers The robots must be VEX Cortex controlled

Basic Information

Basic Information

Returnables kit must be returned at the conclusion of the competition unless the kit will be purchased

Do not modify or paint returnable kit parts except for servo horns and the toothed belt segment

All robots will be inspected for compliance with rules before the contest.

Robots may be inspected at any time a judge suspects that a robot is out-of-compliance

Batteries

Two 7.2 Volt, 3000 mAhrNiMH chargeable batteries

Six 1.2 Volt, 800mAhr NiMH chargeable AAA cells

One standard 9 Volt battery

Manage your batteries carefully!– Turn power off when robot is not running– Recharge batteries when robot performance first

indicates a drop in power.– Minimize number of charge cycles

Team-owned batteries are not allowed on the field on game day

Batteries

Battery Chargers

Chargers are included in the return kit Read charger instructions and follow carefully! Battery will become warm during a charge If a battery becomes hot during a charge,

disconnect from charger immediately! Batteries can explode!

Two blue 7.2 Volt batteries are included in the Return kit

Only one battery can be connected to the robot

Both batteries may be charged at the same time

the larger of the two power supplies works with the blue charger.

The 9 volt battery may be used for backup power via a special port on the Controller

Cortex Microprocessor Battery Charger

Battery charger for six re-chargeable AAA cells that power the Joystick

Do not try to charge standard AAA cells

The AAA cells are installed inside the Joystick unit and accessed with a small Phillips screwdriver

Only the smaller of the two power supplies works with the AAA cell charger

VEXnet Joystick Battery Charger

VEXnet Joystick

Joystick communicates with Cortex controller via wireless 802-11g

Two X/Y joysticks plus 12 programmable buttons

Ports on the back are:- Partner – phone cord to another Joystick shares control (buddy system)- Program – programming cable from PC USB port- Competition - ?

On/Off power switch

Back-side view

Top view802.11 Adapter

Cortex M3 VEXnet Controller

10 motor/servo ports

12 Digital I/O ports

8 Analog ports Two UART (data) portsOne 12C (sensor) port

Backup power port(9V battery)

Rx 2 Rx1 7.2 V battery port

On/Off Switch

802.11 Adapter

• 2 built-in speed controllers

• 2 external speed controllers

Cortex Controller Wiring Plan

Black, - Gnd Red, +White, Control/Signal

Two Wire Black – Red +

Black, - Gnd

Red, +5

White, control/signal

- Gnd

+ 5 V

Rx (clock for 12C

Tx (Data for 12C

VEX Control System

Switch

Servos

Small motor

Large motor

Large motor

Speed controllers

Install VEX Cortex with two screws not too tightly Provide easy access to VEX Cortex power switch

and battery The battery must be secured to the robot without

applying tape or adhesive to the battery Wire Red to Red (+) and Black to Black (-)

Recommendations

VEX Programming System

•EasyC or RobotC software must be installed on a laptop or PC.

•Programming may be downloaded to the VEX controller without disconnecting the controller from peripheral devices

Servos

•Connect to the VEX Controller

•Used to control microswitches, or drive mechanisms (like grippers, releases, etc.)

•Do not open or otherwise modify servos!

•You can change/modify the horns (wheels).

DC Motors

• Do not disassemble or modify motors

• Connections to motors should be made with crimped terminals from the consumables kit

• Reverse power connections to reverse direction of rotation

Power Switching

Motion Example

Example Robot with obsolete BRAIN

Wheel Hubs and Shaft Extenders

Recommended Tool List

Emerald Coast BEST Tool Kit RecommendationsItem Part Number Price

Drill Motor 3670 19.99

Multimeter 90899 4.99

Saber/Jig Saw 92772 29.99

File Set 7520 6.99

Terminal Crimper 92410 2.99

Drill Set 9475 3.99

Spade Drill Set 38597 5.99

Hacksaw 40766 3.99

Tool Set * 91507 44.99

Total 123.91

*Tool set includes measuring tape, screw drivers, sockets, wrenches, pliers, allen wrenches, hammer, etc.

Tool source is Harbor Freight. Equivalent tools may be purchased from other sources.