===== Config.txt Configuration =====
To use UART, CFNET, and PCIe SSD functions on the Modular Pi, you must add the following content to the **config.txt** configuration file. \\ 

**※ This is a mandatory requirement for using expansion modules (CFNET I/O).**
  * To edit config.txt: **''sudo nano config.txt''**
  * **Bookworm OS:** /boot/firmware/config.txt
  * **Bullseye & Buster OS:** /boot/config.txt

<code>
[pi5]
pciex1=on 
dtoverlay=uart0-pi5 
dtoverlay=uart4-pi5 
dtoverlay=i2c0-pi5,pins_8_9,baudrate=100000 
dtoverlay=i2c1-pi5,pins_2_3,baudrate=1000000 
dtoverlay=i2c3-pi5,pins_22_23,baudrate=1000000
</code>

{{ :modularpi:python:seting:config_txt.png?nolink |}}

===== Installing Python I2C Library (smbus2) =====
CFNET I/O expansion modules are designed to be controlled via I²C (CFNET) communication. Therefore, to use I²C communication in Python, you must install the **smbus2** library as shown below. 
  * Install smbus2 library: **''sudo apt-get install -y python3-smbus''**
  * Verify installation: **''dpkg -l | grep python3-smbus''**

{{ :modularpi:python:seting:setup_smbus.png?nolink |}}

===== Verifying Connected CFNET I/O Modules =====
After completing the settings above, you can verify the expansion modules (CFNET) connected to the Modular Pi using a simple command.
  * Install I²C device scan and control utilities: **''sudo apt-get install -y i2c-tools''**
  * Check connected devices: **''sudo i2cdetect -y 3''**

{{ :modularpi:python:seting:i2c_scan.png?nolink |}}

===== Update / Upgrade =====
The Operating System (OS) should be kept up to date through **update** and **upgrade** commands. Using older versions may cause compatibility issues; maintaining the latest version ensures the system operates more stably. 
Additionally, development tools such as Python, Node.js, and GCC should be kept at their latest versions to guarantee compatibility with modern libraries.

  * Upgrade: **''sudo apt-get upgrade -y''**

{{ :modularpi:python:seting:update.png?nolink |}}

[[..:index|CFNET I/O Development Using Python]]