Updated 07/19/2010

Safety first! Wear eye protection and never touch a powered robot!

Note: Do not use Loctite or thread locks on the assembly. They are not necessary and may cause damage to the Lexan.

Note: This guide follows the assembly guide. The Sabertooth 2x5 R/C has already been installed.

Software:
  - Basic Micro Studio

Use an exacto knife to carefully pry the black tab up and slip the red wire out of the black housing as shown in Figure 2.

Bend the red wires up and use electrical tape to cover them as shown. This will prevent accidental shorts.

Schematic - Figure 4 (Old approach using Step 2B).

Schematic - Figure 4.

Now it's time to have some fun!

This program requires the Sabertooth's Switch 1 to be flipped to the "Off" or "Independent Control" position.

Upon powering up the robot, you should hear four ascending notes. Pressing A once results in a beep and slow forward motion (10%) on the left channel only. Pressing nine more times results in 100% power. Continuing to press A will make the motor act as above, except only for the right channel. The C button will control the left motor in a similar manner. Pressing the B button will reset the speed and direction of both left and right.

Note: The Sabertooth's red Error LED will light to indicate overheating or current limit. The blue Status LED will glow dimly when power is applied, and brightly when a radio signal is present. In Lithium mode, the blue Status LED will flash out the number of lithium cells detected.

Download this file (a4wd1tst1.zip) and run it. For this program, on the Bot Board II, the "B" button is throttle and the "A" and "C" buttons are steering.

Upon powering up the robot, you should hear four ascending notes.  Pressing B once results in a beep and slow forward motion (10%). Pressing nine more times results in 100% power. After the motor is at 100% power, pressing B will reduce the speed in 10% increments until it stops. Continue to press B to make the robot move as above, only in reverse.

Press Reset, then B twice. Now press C a few times to see the robot make a gradual left turn. Pressing A a few times will return to forward motion, and continuing to press A will result in gradual right turn.

Experiment with these buttons to understand how throttle and steering can be used to control the vehicle's motion.

Note: The Sabertooth's red Error LED will light to indicate overheating or current limit. The blue Status LED will glow dimly when power is applied, and brightly when a radio signal is present. In Lithium mode, the blue Status LED will flash out the number of lithium cells detected.

If you are adding a pan and tilt and gripper, you will need to change the power bus jumpers according to Table 8 and Schematic 9.

Figure 8.

Schematic - Figure 9.

Schematic - Figure 9.

Before running the program turn on the PS2 controller. When the program is run it will turn most PS2 game controllers to analog mode (required) automatically. If your controller does not automatically go into analog mode, you will need to do so manually.

This program also incorporates speed limits. There are four speeds, #1 being slowest and #4 being fastest. #3 is default. The speed limit is increased by pressing L1 and decreased by pressing L2. By reducing the top-end speed, you can use the full range of the joystick at a lower speed, thus increasing the accuracy of the rover's movements. This is helpful when trying to position the gripper over an object to pick up.

When the program is started, the program will read the joystick positions and set those values as the "nulled" position. Pressing the Start button will null the joysticks on command. Robot movements are proportional to the joystick travel from null, and linear in both directions after the deadband. This helps with PS2 controllers that don't reliably return to 127 for joystick center.

See Table 11-1 for a complete list of programmed controls.