Electronics Housing Assembly

The circuit assembly secures and houses the raspberry pi and control PCB and protects it from accidental roll-overs.

After completing this section, it is possible to power the dog externally from a power supply unit. You can then begin programming and using the robot. The following sections are optional for additional features, such as battery operation, emergency machine off button, vision, sound, etc.

Requirements

ToolsHardwarePrinted Parts

• Phillips and Flat Head Screwdriver
• Scissors
• Wire Strippers
• M2.5 hex key
• M4 hex key
• 12V Power Supply (Or Battery, 10-14V, for testing)

• 4x 5mm M2.5 standoff
• 4x 11mm M2.5 standoff
• 4x M2.5x5 machine screw
• 4x M3x8 machine screw
• 2x M5x10 machine screw
• 4x M3 nut
• 1x T-slot End-Feed Double Nut
• 1x 12mm XYZrobot Smart Servo Cable
• 2x Self-Locking Push Button Switch
• 1x 3W 8ohm Speaker
• 1x speaker amplifier board (with screw terminals soldered)

• 1x Circuit Mount
• 1x Circuit Cover

Base Assembly

1. Secure the 3D-printed circuit mount to the center top of the dog using an End-feed double nut and two M5x10 screws. Press M3 nuts into the hex recesses on the inside tabs of the circuit mount.
   
   

2. Thread the 5mm standoffs into the holes in the circuit mount, as shown.

3. Place the Raspberry Pi computer on top of the standoffs, as shown. It is helpful to have the SD card flashed with the latest version of Raspian already inserted in the Raspberry Pi at this time. If you do not have a flashed SD card, you can still insert it later.

4. Screw the 11mm standoffs through the Raspberry Pi mounting holes into the top of the already installed standoffs.
   

5. Place the Control PCB onto the Raspberry Pi so that the mounting holes are inline with the standoffs and the headers mesh.
   

6. Secure the top Control PCB with four M2.5x5 machine screws.
   

Leg and Battery Wiring

1. Using a 12mm Servo Cable, connect each leg to the PCB using the white servo headers and the free socket on the shoulder servos of each leg.

2. Connect the PCB Battery Connector wires to the battery screw-terminals on the PCB.

Housing Assembly

Speaker

1. Attach the speaker to the cover using 2 M2x8 screws. Make sure the speaker is oriented so the wires face down.
   

Switches

1. Cut 4 pieces of wire ~100mm in length.

2. Solder the wires to the solder tabs on the push-button switches. Be sure not to over heat the solder tab.
   
   

3. Optionally, apply heat shrink to the solder joints, as shown.

4. Secure the switches to the cover. Use the plastic nut on the bottom to secure the switches in place.
   
   

Speaker Amplifier Wiring

1. Cut 2 pieces of wire ~120mm in length, to be used to power the speaker amplifier.

2. Connect the two wires to the 5V power input on the speaker amplifier board using the screw terminals. Connect the three wires from the audio cable to the audio input of the speaker amplifier board, as shown.
   
   From top-down view from left to right on the audio input, the wire colors are red, black, white.
   

3. Connect the wires from the speaker to the amplifier board, as shown.
   

4. Using a small piece of adhesive (or velcro adhesive), adhere the amplifier board to the side of the cover, near the speaker, as shown.
   

5. Connect the wires from the cover to the PCB, as shown. The wire pair from one of the push-buttons conencts to the screw terminals of the ON/OFF terminal on the PCB; the wire pair from the other push-button connects to the screw terminals of the MSTOP terminals on the PCB. The wires to the speaker amplifier board connect to the 5V terminal on the PCB. Make sure the polarity is correct for the wires connecting to the amplifier board. See image below. Use zip-ties to secure the wires together in a bunch.

6. Plug the 3.5mm barrel end of the audio cable into the audio port of the Raspberry Pi.

Cover Final Assembly

1. Secure the cover to the circuit mount part using 4x M3x8 screws and 4x M3 nuts. The nuts are recessed into the circuit mount part.