• Work in progress...

🔌 Electronics Assembly

Step 1: Install Core Components

• Push the switch in the space made for it in the Buck Converter Support part.
• If using an INA260 (Battery % monitor), secure it to the side of the Buck Converter Support using 1 self-tapping screw (You should have some that came in with the MG996R servo).

• Connect a 35cm length of wire to the out poles of the Buck Converter used for the servo.
• Using 3 M3x5mm screws (identified by the red arrow), attach the 2 buck converters in the same orientation shown in the picture.
• Use the Buck Converter Bracket part to hold the buck converter used by the Raspberry Pi.

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Step 2: Wire Power Connections and Adjust Voltage

Power cable wiring diagram. Following this diagram, use 20AWG wire to link everything. Keep the wires short to the components within the support, you can have a longer length going to the battery (15cm max).

It should look like this once completed.

• Insert the Battery charger plug in the support and use an M3x8mm screw to hold it in place.

• Connect the Battery and turn the power ON.
• Using a small screwdriver, turn the screw to adjust the buck converter to output 6.2V (It might take several turns before you see a change).

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Step 3: Install Raspberry Pi

• Place the Raspberry Pi on its support and use 2 M3x8mm screws and the Raspberry Pi Support Bracket to hold it in place.

• Place the Raspberry Pi and support on top of the buck converter assembly and secure it in place using 2 M3x5mm screws.

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Step 4: Create Wire Loom and Final Connections

• Create the wire loom to connect the PCA9685 and the INA260 (if using) to the Raspberry Pi following this schema.
• Use about 35cm of wire length for the wires going to the PCA9685.
• You can use 22AWG or 24AWG wire for this if making your own wire loom with dupont connectors, otherwise use 30cm premade dupont connector (and splice the wire if you are using an INA260).

At this stage, the electronics setup is complete and you should be able to power the Raspberry Pi, the Servo Controller (PCA9685) and the INA260 (if using). You can keep the charger plugged in while everything is powered on, it will charge the battery at the same time as providing enough power for the computer.

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🔊 Screen, Camera and Audio

• Remove the plastic casing on the USB to AUDIO board and install it on the Lower Chassis Lid using 2 m3x5mm screws.
• Using Velcro Straps, install the Battery on the Chassis Lid in this orientation, if the Velcro Straps are too long you can cut them.

💻 Raspberry Pi OS Installation

🧩 What You’ll Need

• Raspberry Pi 5
• Active Cooler
• microSD card (16 GB minimum, 32 GB+ recommended)
• microSD card reader for your computer
• Keyboard and mouse (Optional, you can SSH, or VNC *)
• HDMI cable + Micro HDMI adapter + monitor (Optional, we can use the screen we installed above or you can use VNC *)
• USB-C power supply (27 W official recommended, Optional, we the electronics section shows how you can power the Raspberry Pi)

(* Refer to the How To section on how to SSH or use VNC)

Before anything else, install the active cooler on the raspberry pi. Connecting to a monitor is optional if you know how to SSH to do all of the rest of the installation.

⬇️ Step 1 — Download Raspberry Pi Imager

1. Go to the official Raspberry Pi site:
   🔗 https://www.raspberrypi.com/software/
2. Download and install Raspberry Pi Imager for your operating system (Windows, macOS, or Ubuntu).

💾 Step 2 — Flash Raspberry Pi OS to the microSD Card

1. Launch Raspberry Pi Imager.
2. Click “Choose Device” → select Raspberry Pi 5.
3. Click “Choose OS” → select Raspberry Pi OS (64-bit) (Use Trixie)
4. Click “Choose Storage” → select your microSD card.
5. Click the ⚙️ settings icon (bottom right) to open advanced settings:
   • Enable SSH (optional, for remote access)
   • Set a hostname
   • Configure Wi-Fi (SSID, password, country)
   • Set a username and password
   • Choose locale/time zone/keyboard layout
6. Click Save → then Write.
   Wait a few minutes for the flashing process to complete.

⚙️ Step 3 - Modify the config.txt File for DSI Display - After flashing is complete, open the boot partition on your SD card (should show up as a drive in File Explorer). - Open the file: config.txt. - Scroll to the bottom and add the following lines:

dtoverlay=vc4-kms-v3d
dtoverlay=vc4-kms-dsi-waveshare-panel,7_0_inchC,dsi0

NOTE: You may already have the “dtoverlay=vc4-kms-v3d” line in your config.txt. In that case, you DO NOT need to add it again. - Save the file. - Right-click the SD card and choose Eject.

🔌 Step 4 — Boot the Raspberry Pi 5

1. Insert the microSD card into your Raspberry Pi 5.
2. Connect the monitor, keyboard, mouse.
3. Connect the power cable

🔄 Step 5 — Update the System

Once you reach the desktop or connect via SSH, open a terminal and run:

sudo apt update && sudo apt full-upgrade -y 
sudo reboot

This ensures you’re running the latest kernel and firmware optimized for Raspberry Pi 5.

🧩 Step 6 - Enable Interfaces

If you need to enable interfaces like camera, I2C, or SPI, run:

sudo raspi-config

Then navigate to Enable the Camera, I2C, SPI, VNC.

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🧠 TARS Software Installation

📂 Step 1 — Clone the TARS-AI Repository

1. Open a terminal on your Raspberry Pi.
2. Install Python venv (if not already installed) and clone the repository:

sudo apt install python3-venv -y

git clone https://github.com/TARS-AI-Community/TARS-AI

3. Navigate to the cloned directory:

cd TARS-AI

4.Update script permissions:

chmod 777 Install.sh

5. Allow the script to be executable:

chmod a+x Install.sh

6. Run the installation:

./Install.sh

🔑 Step 2 — Configure API Keys

To enable LLM and TTS functionality, you need to configure your API keys.

• Open the .env file in the TARS-AI folder in a text editor and replace the placeholders with your valid API keys:

sudo nano .env

• Get Your API Keys

  Required:

  • OpenAI API Key

  Recommended:

  • Elevenlabs API Key
  • Picovoice

OpenAI is not free but it is also not expensive, Elevenlabs has a free tier and usually is enough for normal use, there are other free options in the software that can be used for free too.

📝 Step 3 - Configure the Program:

• From the TARS-AI folder, navigate to the software source directory:

cd src/

• Open the config.ini file in the TARS-AI\src folder in a text editor and edit the options.

sudo nano config.ini

▶️ Step 4 - Run the Program:

• From the TARS-AI folder:

python App-Start.py

Or

• From the TARS-AI folder, Navigate to the software source directory:

cd src/

• Activate the Virtual Environment, the virtual environment must be activated each time you want to start the program:

source .venv/bin/activate

• you should now see (.venv) in your terminal shell prompt:
• Start the TARS-AI assistant:

python app.py

Note that while the program will run if there was no errors in the previous steps, a microphone and a way to output sound is required to interact with it. For now, you can use an USB microphone and something like bluetooth speakers if you want to test the Software while you are building the rest of the Robot.

📦 Torso Assembly

Step 1: Install Power Door

Install the power door using some length of filament. Make sure to push the filament completely through the hole on both sides of the case. Cut any filament that might be protruding from the hole.

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Step 2: Assemble Main Chassis and Speaker Modules

Connect the Lower Chassis to the Upper Chassis using the middle, left and right Chassis Connectors and 12 M3x10mm screws.

Pass each speaker module through the side opening in the Upper Chassis, ensuring that enough wire is pulled through on each side.

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Step 3: Build and Install Leg Mount Assemblies

Assemble the Left and Right leg mount assembly using 4 M3x35mm screws to link the Channel, Pusher, Pusher Guide and Shaft.

Important:

• Each assembly should slide easily without having any play
• The pusher guide should also move freely
• The left and right assembly should mirror each other

Using 8 M3x18mm screws, attach the Left and Right assembly. Make sure the audio wire goes in the hole of the assembly on each side - this is where all wires are going to be channeled to each leg.

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Step 4: Position Main Servos and Route Wiring

Arrange all 4 main MG996R servos as shown in the image. The number on each one corresponds to the pin ID they will be connected to on the servo controller. Servo 2 and 3 wires need to go through the Left and Right holes where the audio wires are going through.

For Arms Version builders only: Feed the extension servo wires through the Left and Right holes and identify them for later (tape and marker works well).

• Left side: 3 wires for pins 4, 5, 6
• Right side: 3 wires for pins 7, 8, 9

If you are not building the Arms version, you can skip the extension wires.

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Step 5: Install Servo Controller and Electronic Support

1. Secure the PCA9685 board to the Servo Controller Support using 2 self-tapping screws (included with MG996R servo)
2. Feed the wires through the middle hole and out of the top hole so they are not in the way of the left and right assembly
3. Connect the wires to the corresponding pins on the PCA9685
4. Pull all wire slack out of the main torso (there is more than enough room in the leg for extra length)
5. Secure the servo controller support on the Upper Chassis using 4 M3x5mm screws

Using 4 M3x8mm screws, secure the electronic support to the Lower Chassis. Once everything is in place, it should look like the images above.

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Step 6: Install Servo Horns and Hull Hubs

Using 4 self-tapping screws and 2 servo horns with 2 prongs (included with MG996R servo), attach them to the left and right servo connectors.

Slide the left and right Hull Hub on both sides. Important: They can only be installed at this step, so make sure the orientation matches the image.

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Step 7: Set Initial Servo Positions

At this point, all electronics should be working on battery power. We will now set the initial position of the servos and assemble them in place.

Navigate to the servo tester app:

cd TARS-AI
cd src
source .venv/bin/activate
python app-servotester.py

Run Command 1: Set all servos to preset position

Warning: The servos will remain under power while we add components. While they will try to keep their position, it is important to avoid forcing them to move. We can adjust minor misalignment later.

Position the assembled Servo Connector so the servo horn is parallel to the servo as much as possible. Each servo is slightly different, so it might not line up exactly, but we can fix this later. Do this for both Left and Right sides and use the M3 screw (included with servo) to secure in place.

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Step 8: Prepare and Install Modified Servo Horns

Cut one side of 2 servo horns with 2 prongs (included with MG996R servo).

Position the modified horns on the Torso servos at a 90-degree angle. If it's not exactly 90 degrees, we can adjust the minor difference later. Do this for both sides - they should mirror each other.

Put the Servo Connector Arm on top of each side and use 2 M3x8mm screws to secure everything in place.

At this stage, you can disable power to the servos using the script:

Run Command 4: Disable all servos

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Step 9: Final Servo Mounting

Using 4 M3x20mm screws, attach the left and right servos to the leg mount. Note: The screws go in at an angle.

Using 2 M3x20mm screws, attach the servo connector arm on the Pusher. Important: Make sure it's not too tight. Do this for both sides and position the servos back in place in the case.

Use 4 M3x18mm screws to bolt down the left and right Torso Servo Clip. I am also using a small tie-wrap to bundle the wires together here so they do not get caught in the mechanism.

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🦿Legs (No Arm Version)