The Complete Hexapod 2 Tutorial

> <a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-2dof-hexapods/the-complete-hexapod-2-tutorial/WebHome/h2prog1.zip" target="_blank">h2prog1.zip</a> RC.

19

> <a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-2dof-hexapods/the-complete-hexapod-2-tutorial/WebHome/h2prog2.zip" target="_blank">h2prog2.zip</a> RC.

20

> <a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-2dof-hexapods/the-complete-hexapod-2-tutorial/WebHome/h2prog3.zip" target="_blank">h2prog3.zip</a> RC.

21

> <a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-2dof-hexapods/the-complete-hexapod-2-tutorial/WebHome/h2prog4.zip" target="_blank">h2prog4.zip</a> RC.

22

> <a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-2dof-hexapods/the-complete-hexapod-2-tutorial/WebHome/h2l56p5.zip" target="_blank">h2l56p5.zip</a> RC.

23

> <a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-2dof-hexapods/the-complete-hexapod-2-tutorial/WebHome/h2prog6.zip" target="_blank">h2prog6.zip</a> RC.

24

> <a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-2dof-hexapods/the-complete-hexapod-2-tutorial/WebHome/h2prog7.zip" target="_blank">h2prog7.zip</a> Autonomous!

25

Resources:

26

- Wiring Schematic (<a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-2dof-hexapods/the-complete-hexapod-2-tutorial/WebHome/wd001.gif" target="_blank">wd001.gif</a>)

27

- Wiring Schematic (<a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-2dof-hexapods/the-complete-hexapod-2-tutorial/WebHome/h2l56wd.gif" target="_blank">h2l56wd.gif</a>)

28

Goal:

29

- Install, program, and test the electronics to operate a Hexapod 2 with optional L5/L6 arm from a

30

Lynxmotion, MadCatz, Pelican, or Hiteck wireless controller.

</td>

Image of Hexapod 2.

</td>

</tr>

<tr>

</tr>

<tr>

</td>

</tr>

<tr>

</tr>

<tr>

<td valign="top" align="left">Step 1.

50

Install the Bot Board and SSC-32 onto the top of the robot as shown.</td>

Figure 1.</td>

</tr>

<tr>

</td>

</tr>

<tr>

<td valign="top" align="left">Step 2.

60

Connect power wires for the servos as illustrated. Click on Figure 2 for a larger, printable

61

version. Install VS1 = VS2, VL = VS1, TX and RX, and both Baud jumpers for these tests. This will set the Baud rate to 115.2k and allow DB9

62

communications. Consult the SSC-32 user manual for more detailed information.</td>

Figure 2.</td>

</tr>

<tr>

</tr>

<tr>

<td valign="top" align="left">Step 3.

71

Connect the servos to their appropriate I/O channels. See Table 1 and consult the SSC-32

72

users manual. Double check your work. The header pins are close and numerous.

<td >

</center><center>

</center><table border="1" bordercolor="#000000" width="320">

83

84

85

<td width="75%" align="center" bordercolor="#808080" bgcolor="#C0C0C0">Servo</td>

</tr>

<tr>

<td width="75%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Right Rear Vertical</td>

</tr>

<tr>

<td width="75%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Right Rear Horizontal</td>

</tr>

<tr>

<td width="75%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Right Middle Vertical</td>

</tr>

<tr>

<td width="75%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Right Middle Horizontal</td>

</tr>

<tr>

<td width="75%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Right Front Vertical</td>

</tr>

<tr>

<td width="75%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Right Front Horizontal</td>

</tr>

<tr>

<td width="75%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Left Rear Vertical</td>

</tr>

<tr>

<td width="75%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Left Rear Horizontal</td>

</tr>

<tr>

<td width="75%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Left Middle Vertical</td>

</tr>

<tr>

<td width="75%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Left Middle Horizontal</td>

</tr>

<tr>

<td width="75%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Left Front Vertical</td>

</tr>

<tr>

<td width="75%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Left Front Horizontal</td>

</tr>

</tbody></table>

</div>

</td>

</tr>

<tr>

Table 3.</td>

</tr>

</tbody></table>

</center></div>

</td>

Figure 3.</td>

</tr>

<tr>

</tr>

<tr>

<td valign="top" align="left">Step 4a.

156

Connect the serial data cable to the PC's serial port. This can be recognized by having 9 pins

157

that stick out.

158

Step 4b.

159

Connect the other end of the serial data cable to the SSC-32's DB9 port. Turn on the power.

160

Note, you can also use an IOGear USB-to-Serial adaptor.</td>

Figure 4.</td>

</tr>

<tr>

</td>

</tr>

<tr>

<td valign="top" align="left">Step 5.

170

Install and run the LynxTerm on your PC. This program uses your computer's serial port to

171

"talk" to the SSC-32. We will use it to quickly test your hexapod robot. This tool can also be extremely useful if you want to write a

172

program for your favorite microcontroller to talk to the SSC-32 directly.

173

Choose the COM Port for your computer from the drop down menu in the upper left corner.

174

Note, if you notice the text going below the bottom of the box, it may be necessary to change the font settings

175

and / or change the number of rows on screen under the Terminal Setup.

176

Click in the black text box and type "ver". If everything is working correctly, you should receive a

177

response such as "SSC32-1.03XE".

</td>

Figure 5.</td>

</tr>

<tr>

</tr>

<tr>

<td valign="top" align="left">Step 6.

188

Click on the Sequencer button in the lower left corner. Click "All = 1500" and notice

189

the hexapod legs hold position. If the robot was constructed properly, the legs will be horizontal and perpendicular to the body. Now would be a

190

good time to double check the H2 mechanical leg alignment.

191

If your robot does not have mechanical alignment, then use the Offset tool under Servo Quick Test. Select the

192

servo on the Hexapod diagram and adjust the offset slider to fine-tune the leg alignment. Do this for all twelve servos. When completed, click

193

on Config to display the configuration data. Ignore the first four lines, as they do not pertain to the offset command. The lines starting with

194

"#0PO" can be cut and pasted into the serout command in the programs included with this tutorial. Do a search for "Servo

195

Offset" in the supplied programs and follow the instructions.

</td>

Figure 6.</td>

</tr>

<tr>

</tr>

<tr>

<td valign="top" >Step 7.

206

The values for the L* and R* textboxes will control the positions the legs are moved to in the

207

sequence. You can fine-tune these values to your mechanical leg arrangement with the same Servo Quick Test. Just adjust the position slider

208

instead of the offset slider.

<td >

<td align="center" bordercolor="#808080" bgcolor="#C0C0C0" colspan="4">Tripod Leg

219

Movement Sequence</td>

</tr>

<tr>

<td width="22%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Left Front Horiz</td>

224

225

<td width="22%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Right Front Horiz</td>

</tr>

<tr>

<td width="22%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Left High Vertical</td>

230

231

<td width="22%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Right High Vertical</td>

</tr>

<tr>

<td width="22%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Left Middle Vertical</td>

236

237

<td width="22%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Right Mid Vertical</td>

</tr>

<tr>

<td width="22%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Left Low Vertical</td>

242

243

<td width="22%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Right Low Vertical</td>

</tr>

<tr>

<td width="22%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Left Rear Horiz</td>

248

249

<td width="22%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Right Rear Horiz</td>

</tr>

</tbody></table>

</div>

</td>

</tr>

<tr>

<td >

Table 7-1

</td>

</tr>

</tbody></table>

</center>

</div>

</td>

Figure 7.</td>

</tr>

<tr>

</td>

</tr>

<tr>

<td valign="top" align="left">Step 8.

273

Now to make the robot walk forward. Adjust the XL and XR sliders to 100%. Note that HT=1500uS (1.5 seconds). Set the XS slider to ~50% and

274

notice that the stride takes 3 seconds. Adjust the HT slider to 1000 and notice that the stride now takes 2 seconds.

275

You have complete control over all aspects of the tripod gait. Adjust either XL or XR lower to do gradual

276

turns. Setting XL and XR to opposite directions will cause the robot to turn in place. Reverse values of XL and XR will cause the robot to walk

277

backwards. Moving a slider is the same as typing from the terminal or sending the command from a microcontroller. For example, moving XS to 50%

278

is the same as sending "XS50". Once the commands are sent, the robot will continue to walk until it receives XS = 0. If you are using

279

a host microcontroller to send commands, it will be free to do any timing-intensive tasks without worrying about any of the walking process.

</td>

Figure 8.</td>

</tr>

<tr>

</tr>

<tr>

<td valign="top" align="left">Step 9.

290

For the do-it-yourselfers, the program to the right will set up and initiate walking on the robot. It will be necessary to remove the TX and RX

291

jumpers, install the data cable to the Bot Board, and configure the Baud rate jumpers for 38.4k. Refer to the schematic in Figure 12. To change

292

speed and direction just alter the XL, XR, XS values. The robot will immediately begin walking in the speed and direction commanded. We have

293

several fully functional programs to choose from below.</td>

<td bordercolor="#000000">XL var sbyte

XR var sbyte

XS var byte

XL = 100

XR = 100

XS = 100

start:

serout p15,i38400,["LF1700 RF1300 LR1300",13]

309

serout p15,i38400,["RR1700 LH1000 LM1700",13]

310

serout p15,i38400,["LL1800 RH2000 RM1300",13]

311

serout p15,i38400,["RL1200 VS3000 HT1500",13]

312

serout p15,i38400,["XL",SDEC XL,"XR",SDEC XR,13]

313

serout p15,i38400,["XS",DEC XS,13]

loop:

goto loop</td>

</tr>

<tr>

Table 9.</td>

</tr>

</tbody></table>

</center>

</div>

</td>

</tr>

<tr>

</tr>

<tr>

<td valign="top" >Step 10.

331

The following steps refer to several programs that offer complete control of all aspects of the

332

hexapod gait sequence through a wireless PS2 controller. Install and run the BASIC Atom IDE to allow programming the chip.

<td >

<td width="30%" align="center" bordercolor="#808080" bgcolor="#C0C0C0">Filename</td>

343

<td width="70%" align="center" bordercolor="#808080" bgcolor="#C0C0C0">Program description</td>

</tr>

<tr>

<td width="70%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Differential tank-steer mode.</td>

</tr>

<tr>

<td width="70%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Above, and single joystick

mode.</td>

</tr>

<tr>

<td width="70%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Above, and leg high-position

adjustable.</td>

</tr>

<tr>

<td width="70%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Above,  leg low-pos.

362

adjustable, and obstacle detection.</td>

</tr>

<tr>

<td width="70%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Above, and L5/L6 arm control.</td>

</tr>

<tr>

<td width="70%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Same as h2prog4, except only

371

single joystick mode and pan-and-tilt on left joystick.</td>

</tr>

</tbody></table>

</div>

</td>

</tr>

<tr>

<td >

Table 10-1

</td>

</tr>

</tbody></table>

</center>

</div>

</td>

Figure 10.</td>

</tr>

<tr>

</td>

</tr>

<tr>

<td valign="top" align="left">Step 11.

395

Wire your robot as illustrated in the wiring diagram to the right. Click on Figure 11 for a larger,

396

printable version. The Sharp GP2D12 is not required, but offers crash protection if installed. You can use 7.2vdc battery for the best

397

performance, however, if you're installing an L5 or L6 arm 6.0vdc is recommended. This is due to the micro servo on the gripper. For increased

398

runtime, you can power the logic of the Bot Board and SSC-32 from a 9v battery. Just remember to remove the VS=VL jumpers on both boards. Don't

399

forget to install the speaker enable jumper. This will provide audible feedback when using the controller with the provided programs. Install

400

the PS2 receiver module and put fresh batteries in your controller.

401

When you run the program, you should hear some beeps that will continue until the game controller is

402

recognized. Press the Analog button and the legs should hold position.

</td>

Figure 11.</td>

</tr>

<tr>

</tr>

<tr>

<td valign="top" align="left">Step 12.

413

Install the Playstation 2 cable as illustrated in Figure 12-1 and 12-2.

Figure 12-1

</td>

</tr>

<tr>

<td >

Figure 12-2

</td>

</tr>

</tbody></table>

</center>

</div>

</td>

</tr>

<tr>

</td>

</tr>

<tr>

<td valign="top" align="left">Step 13.

440

Controlling the motion of the hexapod is handled in two ways. Make sure the controller is in Analog mode. Mode 1 (default) uses a differential

441

or tank mode, where the right joystick controls the right legs, and the left joystick controls the left legs. Mode 2 allows control of the

442

direction of walking with the right joystick, while Left and Right on the D-Pad adjusts speed. Pressing R3 swaps between control modes.

443

Initially, in either mode the joystick positions will allow a max of 100% XS speed. Pressing D-Pad Left lowers the max in 5% increments, and

444

D-Pad Right increases the max in 5% increments up to 200%

445

Both modes offer additional control of leg trajectory for the alternating tripod gait. This refers to the

446

vertical and horizontal motion that the foot goes through during the walking gait. Pressing /\, O (default), X, or [] changes how the

447

foot is lifted in relation to the stride motion. Control the max vertical height with the R1/R2 buttons. Control the max low position (H2 body

448

ride height) with the L1/L2 buttons. This can also be done with the D-Pad Up and Down buttons with a faster response.

449

If the robot is driven toward an obstacle, after a threshold is reached the forward joystick position is

450

ignored. However, you can still reverse direction. The controller will also vibrate proportionally in relation to the distance from the

451

obstacle. The Sharp sensor can be enabled or disabled with the Start button.

</td>

Figure 13.</td>

</tr>

<tr>

</td>

</tr>

<tr>

<td valign="top" align="left">Step 14.

463

The Select button switches between Hexapod and Arm control.

464

- Move X and Y (Up/Down, To/Away) with the Left joystick.

465

- Move Z (Base Rotate) and Wrist Angle with Right joystick.

466

- Close/Open gripper with L1/L2 buttons.

467

- Turn Wrist (L6 only) Right/Left with the R1/R2 buttons.

468

> Arm moving <a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-2dof-hexapods/the-complete-hexapod-2-tutorial/WebHome/eh2l600.mpg">video</a>.

469

- Invert the X axis with the L3 (left joystick push button).

470

- Initialize Arm position with the X button.

471

- Disable/Enable Arm servos with the /\ button.

</td>

Figure 14.</td>

</tr>

<tr>

</tr>

<tr>

<td >

<td align="center" bordercolor="#808080" bgcolor="#C0C0C0" colspan="4">PS2 Controls

491

(Default Tank Mode)</td>

</tr>

<tr>

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Left Side Forward</td>

496

497

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Right Side Forward</td>

</tr>

<tr>

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Left Side Backward</td>

502

503

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Right Side Backward</td>

</tr>

<tr>

</tr>

<tr>

</tr>

<tr>

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Raise body height</td>

520

521

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Increase leg lift</td>

</tr>

<tr>

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Lower body height</td>

526

527

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Decrease leg lift</td>

</tr>

<tr>

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Switch control mode</td>

</tr>

<tr>

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Raise body height</td>

538

539

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Figure 12</td>

</tr>

<tr>

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Lower body height</td>

544

545

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Figure 12</td>

</tr>

<tr>

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Speed Limit Down</td>

550

551

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Figure 12</td>

</tr>

<tr>

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Speed Limit Up</td>

556

557

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Figure 12</td>

558

</tr>

559

<tr>

560

<td width="15%" align="center" bordercolor="#808080" bgcolor="#C0C0C0">Start</td>

561

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Dis/En Crash Monitor</td>

562

<td width="15%" align="center" bordercolor="#808080" bgcolor="#C0C0C0">Select</td>

563

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Switch to Arm mode</td>

</tr>

</tbody></table>

</div>

</td>

</tr>

<tr>

<td >

Table 14-1

</td>

</tr>

</tbody></table>

</center>

</div>

</td>

<td >

<td align="center" bordercolor="#808080" bgcolor="#C0C0C0" colspan="4">PS2 Controls

588

(Right-Joystick Mode)</td>

</tr>

<tr>

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Forward</td>

</tr>

<tr>

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Backward</td>

</tr>

<tr>

</tr>

<tr>

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Right</td>

</tr>

</tbody></table>

</div>

</td>

</tr>

<tr>

<td >

Table 14-2

</td>

</tr>

<tr>

<td >

<td align="center" bordercolor="#808080" bgcolor="#C0C0C0" colspan="4">PS2 Controls

(Arm Control)</td>

</tr>

<tr>

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Move Z and Wrist</td>

</tr>

<tr>

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Close Gripper</td>

648

649

650

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Turn Wrist Right</td>

</tr>

<tr>

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Open Gripper</td>

656

657

658

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Turn Wrist Left</td>

</tr>

<tr>

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Invert X Axis</td>

664

665

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Switch control mode</td>

</tr>

<tr>

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Home Position</td>

671

672

673

<td width="35%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Diable/Enable Servos</td>

</tr>

</tbody></table>

</div>

</td>

</tr>

<tr>

<td >

Table 14-1

</td>

</tr>

</tbody></table>

</center>

</div>

</td>

</tr>

<tr>

</tr>

<tr>

<td valign="top" >Step 15.

694

The following autonomous-behavior program requires the addition of three Sharp GP2D12 sensors, connected as follows:

695

696

A to D channel 0 sensor: on front left side, facing right.

697

A to D channel 1 sensor: on front right side, facing left.

698

A to D channel 2 sensor: on rear, facing behind the robot.

<td >

<td width="30%" align="center" bordercolor="#808080" bgcolor="#C0C0C0">Filename</td>

709

<td width="70%" align="center" bordercolor="#808080" bgcolor="#C0C0C0">Program description</td>

</tr>

<tr>

<td width="70%" align="center" bordercolor="#C0C0C0" bgcolor="#FFFFFF">Autonomous using two Sharp

714

GP2D12 sensors and one on the rear.</td>

</tr>

</tbody></table>

</div>

</td>

</tr>

<tr>

<td >

Table 15-1

</td>

</tr>

</tbody></table>

</center>

</div>

</td>

Figure 15.</td>

</tr>

</tbody></table>

</body>

Wiki source code of The Complete Hexapod 2 Tutorial

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