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PC Control These demos and projects allow the robot to be controlled via a computer.

ArbotiX Commander Control - These demos and projects control the Robot using the ArbotiX Commander, the handheld Arduino based remote control.

Direct Control - These demos and projects control the Robot directly from sensors connected directly to the Robot's control board.

Pose Control - These demos and projects allow you to create and playback a sequence of poses.

Serial Control - These demos and projects control the robot using a serial packet protocol.

Standalone - These demos and projects are deisgned to let your robot function without a computer or additional microcontroller.

Wireless Control - These demos and projects allow you to control the robot wirelessly - usually by replacing the Serial Connection with XBee modules.

Reference - These articles have technical details regarding the control and operation of the robot.

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More info here

RobotGeek Parallel Gripper Getting Started Guide

Contents:

  1. Setting up the Arduino Software
  2. Configuring your Servos
  3. Gripper Assembly
  4. Testing the Gripper
  5. Controlling the Gripper

This guide will refer to the RobotGeek Geekduino, the microcontroller that ships with RobotGeek Arm, Rover, and Experimenter's Kits. However this kit will also work with the Arduino Uno, or other Arduino variants like the Seeeduino.

RobotGeek 101

Are you ready to dive even deeper into the world of Arduino? Then take a look at Robotgeek 101! RobotGeek 101 is a step by step guide that will teach you how to build, wire, and program your Geekduino/Arduino. Through RobotGeek 101 you will learn the basics of Arduino like digital input and output, and move on to more advanced topics like PWM and servo control. By the end of RobotGeek 101 you'll be well equipped to start modifying our demo code and creating your own custom applications.

RobotGeek 101

Configuring Your Servos

The RobotGeek Parallel Gripper should be operated within a specific range of positional Values. Operating the gripper outside of the values can cause unnecessary stress on the servo and lead to the motor being burnt out. The 'degree' values can be used with the servo.write() function while the 'microsecond' values can be used with the servo.writeMicroseconds function.
Gripper Orientation Servo Value (degrees) Servo Value (microseconds)
Full Closed - Minimum Value 30° 800µs
Fully Open - Maximum Value 180° 2400µs

Configuring Your Servos

geekmount-pins-note.jpg

Servo motors act like robotic joints - you can set them to specific positions to move your robot to different positions. This means that the servo needs to be set to s specific position before assembling your robot, or it will not work correctly. We are going to 'center' the servos, setting them to halfway between their maximum and minimum position. To begin centering your servos, we're going to have to set up your test rig. This is incredibly easy to do with a RobotGeek Sensor Shield. Start by attaching your Sensor Shield to your Geekduino/Arduino Compatible board. Slot the bottom pins of the RobotGeek Sensor Shield into the terminals in the top of the Geekduino. Note how the boards seat evenly on top of each other, and the pins line up exactly. Be careful not to bend the pins.

First you will need to attach your RobotGeek Sensor Shield to your Geekduino. Then, connect the two servos to the RobotGeek Sensor Shield as shown in the diagram below. If you are going on to build the RobotGeek Snapper Arm, then also plug in the 3 additional RobotGeek Servos as shown in the last diagram.

If you are going on to build the RobotGeek Snapper Arm then you can also configure your other arm servos in this step, or just hop over to the Snapper Arm Getting Started Guide to get up and moving.

Now connect the external power supply to the Geekduino. You can use a 6v or 7v power supply.

Wiring for Gripper Only
Device Sensor Shield Port
Servos
Gripper RobotGeek Servo Digital 10
Wiring for Gripper and Wrist Servo
Device Sensor Shield Port
Servos
Wrist RobotGeek Servo Digital 9
Gripper RobotGeek Servo Digital 10
Wiring for Snapper Arm
Device Sensor Shield Port
Servos
Base Rotation RobotGeek Servo Digital 3
Shoulder RobotGeek Servo Digital 5
Elbow RobotGeek Servo Digital 6
Wrist RobotGeek Servo Digital 9
Gripper RobotGeek Servo Digital 10
b_500_500_16777215_00__images_tutorials_gripper_wiringGripF.png b_500_500_16777215_00__images_tutorials_gripper_wiringWristF.png b_500_500_16777215_00__images_tutorials_gripper_wiringSnapperF.png
Jumpers and Power

RobotGeek servos must be powered by an external power supply like the 7v5A power supply included with your kit. If you have servos plugged in to the shield and do not have the external power supply plugged into your Geekduino you will see erratic behavior.

You will also need to adjust your shield to make sure the power is getting to the servos correctly. Make sure that you have both of the jumpers on the Sensor Shield set to Voltage In (VIN) If you would like more information about this, check out the Jumpers/Power section of the RobotGeek 101 learning series.

b_500_500_16777215_00__images_tutorials_rgSnapperArm_powerA.jpgsnapperArm-jumpers.jpg

Center your Servos

The following code will set any servos on pins 3,5,6,9, and 10 to a centered position (90°). RobotGeek servos should NOT be plugged into pin 11 at this time.

This code will both test and center your servos. Each servo will move do 45 degrees, 125 degrees, then 90 degrees. If you want to restart the movement, just push the reset button on your Geekduino. Make sure to only run this code when nothing is attached to your servos. Running this code on an assembled robot could damage the robot or servos.

File -> Sketchbook -> RobotGeek Sketches -> Tools -> gripperAndArmServos

Once the RobotGeek servos are centered you can install the servo horn with the notch pointing straight up, and install the black screw. The screw will cover the notch, but lining the notch straight up will ensure that the horn is set at the correct angle.

b_500_500_16777215_00__images_tutorials_rgServo_180horn1.jpg b_500_500_16777215_00__images_tutorials_rgServo_180horn2.jpg b_500_500_16777215_00__images_tutorials_rgServo_180horn3.jpg

The Wrist Servo for the gripper will also require a idler horn. Install the idler horn on the back of the servo and secure it with the silver screw. If you are going on to build the RobotGeek Snapper Arm, install idlers on 2 more servos, leaving the last servo with no idler horn.

b_500_500_16777215_00__images_tutorials_rgServo_idlerhorn0.jpg b_500_500_16777215_00__images_tutorials_rgServo_idlerhorn1.jpg b_500_500_16777215_00__images_tutorials_rgServo_idlerhorn2.jpg

See this page for more information and a video on centering servos.

Assembly Guide

Follow the appropriate guide for your RobotGeek Gripper to assemble it, then return to this guide for testing and controlling your gripper.

RobotGeek Parallel Gripper Assembly Guide
RobotGeek Wide Gripper Assembly Guide

Testing the Gripper

To test the gripper, first connect the servos just like in the Servo Configuration step.

Wiring for Gripper Only
Device Sensor Shield Port
Servos
Gripper RobotGeek Servo Digital 10
Wiring for Gripper and Wrist Servo
Device Sensor Shield Port
Servos
Wrist RobotGeek Servo Digital 9
Gripper RobotGeek Servo Digital 10
b_0_505_16777215_00__images_tutorials_gripper_wiringGripF.png
Wiring for Gripper
b_0_505_16777215_00__images_tutorials_gripper_wiringWristF.png
Wiring for Gripper with Wrist Servo

Now load the gripperAuto sketch onto the Geekduino.

File -> Sketchbook -> RobotGeek Sketches -> Test -> parrallelGripperAuto

The sketch will play the following sequence once :

  • Open gripper, wait 1.5 seconds
  • Close Gripper, wait 1.5 seconds
  • Lower Wrist Servo down, wait 1.5 seconds
  • Raise Wrist Servo up degrees, wait 1.5 seconds
  • Level Wrist Servo, wait 1.5 seconds

You can restart the sequence by reseting the Geekduino or powering off/on the system. If the gripper does not follow this sequence, then please check that it is assembled correctly.

Controlling the Gripper

This configuration will allow you to control the gripper using 2 Analog Sensors. This example will work with any analog sensor - this example will use RobotGeek Rotary Knobs.

Wiring for Gripper Only
Device Sensor Shield Port
Sensors
Gripper Control RobotGeek Rotation Knob Analog 1
Servos
Gripper RobotGeek Servo Digital 10
Wiring for Gripper and Wrist Servo
Device Sensor Shield Port
Sensors
Wrist Control RobotGeek Rotation Knob Analog 0
Gripper Control RobotGeek Rotation Knob Analog 1
Servos
Wrist RobotGeek Servo Digital 9
Gripper RobotGeek Servo Digital 10
b_0_505_16777215_00__images_tutorials_gripper_controlGripF.png
Wiring for Gripper
b_0_505_16777215_00__images_tutorials_gripper_controlWristF.png
Wiring for Gripper with Wrist Servo

Now load the gripperKnob sketch onto the Geekduino.

File -> Sketchbook -> RobotGeek Sketches -> Test -> parrallelGripperKnob

By turning the knobs you can control the positions of the two servos.

These servos have no over-current protection. Trying to lift to large of a load or applying to much force to the gripper may damage the servos.

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