🐶Raspberry Pi Setup for the FreeNove Robot Dog: I2C and Required Libraries

Previous article:
🐶 Raspberry Pi 4 Initial Setup

A simple guide to enabling I2C, installing libraries, and preparing your Raspberry Pi for the FreeNove Robot Dog.

This section prepares your Raspberry Pi for running the FreeNove Robot Dog by:

• installing the required Python libraries
• enabling the I2C hardware interface
• verifying that both system modules(software) and I2C devices(hardware) are working correctly

This setup is required before running any robot control code.

Overview of Steps

• Obtain the robot code and ensure Python 3 is used
• Enable required interface(I2C)
• Install Python dependencies
• Verify I2C communication at both system and device levels

📦1. Download the Robot Code

cd
git clone --depth 1 https://github.com/Freenove/Freenove_Robot_Dog_Kit_for_Raspberry_Pi

The project will be cloned into your home directory.

⚙️2. Enable Required Interface(I2C)

You can enable hardware interfaces from the Raspberry Pi desktop UI.

Open Configuration

1. Click the Raspberry Pi icon (top-left)
2. Go to:
   Preferences → Control Centre
   (Authentication required)

※ Do not unslide VNC or SSH.

If you do, then you need to recover ssh and redo the Enable VNC inside raspi-config from previous step. You can leave Serial Port and Serial Console alone.

Required settings:
✅SSH — allows remote terminal access
✅VNC — allows remote desktop connection
✅I2C — required for sensors (MPU6050, PCA9685)

Click Close, then authenticate again.

🔄 Reboot
In Terminal, type:

sudo reboot

Reboot is required for the settings to apply.

📚3. Install Python Libraries

Move to the project directory:

cd ~/Freenove_Robot_Dog_Kit_for_Raspberry_Pi/Code

Run the setup script:

sudo python setup.py

👉 This installs:

• hardware control libraries
• sensor drivers
• GUI libraries (e.g., PyQt5)

🔍4. Verify I2C Module (System Level)

Check that the I2C kernel modules are loaded:

lsmod | grep i2c

Expected output:

i2c_dev        16384  0
i2c_bcm2835    16384  0
i2c_brcmstb    12288  0

💡 What each module means

• i2c_dev — userspace interface (/dev/i2c-*)
• i2c_bcm2835 — main I2C controller driver for Raspberry Pi
• i2c_brcmstb — Broadcom STB I2C driver (newer kernels)

If these appear, I2C is enabled at the OS level.

✅ These are the correct modules for Raspberry Pi OS Bookworm and newer kernels. If you see output → I2C is working at the system level

🔍5. Verify I2C Devices (Hardware Level)

Install tools (if not already installed):

sudo apt-get install i2c-tools
sudo apt-get install python3-smbus

Scan the I2C bus:
(Just keep this in mind for now. You need to build robodog to check the i2c status.)

i2cdetect -y 1

Expected addresses:

0x40 (PCA9685) — controls all robot leg servos(servo controller)
0x48 (PCF8591) — reads analog sensor data(ADC chip)

If both appear, the robot control board is connected correctly.

💡 What do these numbers mean?

• I2C is a communication system used to connect hardware modules
• Each device has a unique address
• i2cdetect scans and lists connected devices

👉 In this robot:
0x40 → PCA9685 (servo controller)
→ controls the robot’s motors (legs)
0x48 → PCF8591 (ADC chip)
→ reads sensor and analog data

If both appear, the robot control board is connected properly.

I²C diagram for reference:

✅ Summary

• Clone the FreeNove repository
• Ensure Python 3 is used
• Enable SSH, VNC, I2C, and Camera
• Install required Python libraries
• Verify I2C communication
  • Check I2C module (lsmod)
  • Check I2C devices (i2cdetect)

🎯 Key Takeaway

There are two levels of I2C verification:

• System level (sofware): lsmod → confirms I2C is enabled
• Device level (hardware): i2cdetect → confirms hardware is detected

Both must be correct for the robot to operate.

👉 Next article: 🛠️Building the FreeNove Robot Dog