Rizmo

Code for my robot, Rizmo.

Hardware

• Head:
  • Wide-angle HD Webcam
  • Yahboom 2-DOF Servo Pan-Tilt Kit
  • 180° Servo with Bracket
  • Pololu Mini Maestro 12-Channel USB Servo Controller
  • DROK 12V to 5V 3A Buck Regulator for servo power
• Computer:
  • NVIDIA Jetson Nano Developer Kit
  • 2x WiFi Antenna
  • EMEET USB Conference Speaker
  • DROK 8-32V to 3-27V 5A Buck Regulator for computer power
• Power:
  • Zeee 7.4V 6200mAh 2S Lipo Battery
  • 8.4V 3A Li-ion Battery Charger
  • 2S 18650 Lithium Battery Balance Charger Board
  • Lithium Battery Capacity Indicator Module - Green

Software Setup

1. Install OS:
   1. Write the Jetson Nano Developer Kit SD card image to a microSD card (instructions).
   2. Power up and install OS.
      • Hostname: rizmo
   3. Remove unnecessary programs. Install updates.
   4. Register for Ubuntu Pro for additional security updates: sudo pro attach <token>, where token comes from here.
2. Setup SSH:
   1. Copy ~/.ssh/id_rsa.pub of dev machine to ~/.ssh/authorized_keys on Jetson Nano.
   2. Set permissions: chmod 700 ~/.ssh && chmod 600 ~/.ssh/authorized_keys
3. Install gcc-9 and g++-9 (required by latest numpy versions):

   sudo add-apt-repository ppa:ubuntu-toolchain-r/test -y
   sudo apt install gcc-9 g++-9 -y
   sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-7 70
   sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-9 90
   sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-7 70
   sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-9 90
   gcc --version  # Verify version is 9.x
   g++ --version  # Verify version is 9.x
   

4. Install and setup pyenv (instructions).
   • To update: pyenv update
5. Install Python 3.12 (with optimizations):
   env PYTHON_CONFIGURE_OPTS='--enable-optimizations --with-lto' PYTHON_CFLAGS='-march=native -mtune=native' pyenv install --verbose 3.12
6. Set default Python version: pyenv global 3.12
7. Set the default audio IO device:
   1. List devices:

      pactl list short sinks
      pactl list short sources
      

   2. Append lines to /etc/pulse/default.pa:

      set-default-sink <sink-name>
      set-default-source <source-name>
      

8. Install the jetson_inference library:
   1. Follow these instructions to install it from source to the system's Python 3.6 site packages.
   2. Create a Python 3.6 venv:
      python3.6 -m venv --system-site-packages --symlinks venv36
   3. Update pip and make sure the lib can be imported:

      . venv36/bin/activate
      pip install -U pip
      pip install -r requirements.py36.txt
      python -c "import jetson_inference"
      

Repository Setup

git clone https://github.com/austin-bowen/rizmo.git
cd rizmo
python -m venv --symlinks venv
. venv/bin/activate
pip install -U pip
pip install -r requirements.<rizmo|potato>.txt

# For sounddevice lib
sudo apt install libportaudio2

# For serial communication
sudo usermod -aG dialout $USER

Setup git:

git config --global user.name "<name>"
git config --global user.email "<email>"
git config credential.helper store

# When trying to push, enter username, and paste personal access token
# generated from here: https://github.com/settings/tokens

Create file rizmo/secrets.py with the following contents:

AWS_ACCESS_KEY_ID: str = ...
AWS_SECRET_ACCESS_KEY: str = ...

OPENAI_API_KEY: str = ...

# Get from: https://developer.wolframalpha.com/access
# Make sure it has "Full Results API" permissions
WOLFRAM_ALPHA_APP_ID: str = ...

Make Rizmo start on system boot:

./bin/install-rizmo-service
sudo systemctl start rizmo

Upgrading Python on Jetson Nano

# Install latest Python version
pyenv update
env PYTHON_CONFIGURE_OPTS='--enable-optimizations --with-lto' PYTHON_CFLAGS='-march=native -mtune=native' pyenv install --verbose 3.12

# Create new venv
echo 3.12.x> .python-version
mv venv venv.old
python -m venv --symlinks venv
. venv/bin/activate
python -V
# <verify it is using latest version>

# Install requirements
pip install -U pip
pip install -r requirements.<hostname>.txt
# <verify everything is working>

# Cleanup
rm -r venv.old
pyenv versions
pyenv uninstall <old-version>