M5Stack_Linux_Libs/doc/tools/linux_debug_tools.md

Linux Debugging Tools

I2C

In Linux systems, I2C (Inter-Integrated Circuit) is a commonly used bus protocol for connecting multiple low-speed peripherals. To debug and test I2C devices, Linux provides some handy I2C debugging tools, mainly included in the i2c-tools package.

i2c-tools Package

i2c-tools is a set of convenient tools for interacting with and debugging I2C devices. This package includes some command-line tools that can be used to scan the I2C bus, communicate with I2C devices, and more.

Installing i2c-tools

In most Linux distributions, you can install i2c-tools using the package manager. For example:

• On Debian/Ubuntu:

  sudo apt-get update
  sudo apt-get install i2c-tools
  

• On Fedora:

  sudo dnf install i2c-tools
  

• On Arch Linux:

  sudo pacman -S i2c-tools
  

Main Tools and Usage

The i2c-tools package includes the following main tools:

1. i2cdetect

i2cdetect is used to scan the I2C bus and list all connected I2C devices and their addresses.

• Scan I2C bus 0:

  sudo i2cdetect -y 0
  

• Scan I2C bus 1:

  sudo i2cdetect -y 1
  

2. i2cdump

i2cdump reads and displays the register contents of an I2C device.

• Dump registers of a device at I2C address 0x50 on I2C bus 1:

  sudo i2cdump -y 1 0x50
  

3. i2cget

i2cget reads the value of a single register from an I2C device.

• Read register 0x10 of a device at I2C address 0x50 on I2C bus 1:

  sudo i2cget -y 1 0x50 0x10
  

4. i2cset

i2cset writes data to a register of an I2C device.

• Write value 0x20 to register 0x10 of a device at I2C address 0x50 on I2C bus 1:

  sudo i2cset -y 1 0x50 0x10 0x20
  

SPI

In Linux systems, there are many tools and packages available for debugging SPI (Serial Peripheral Interface). Here are some commonly used SPI debugging tools with detailed descriptions and usage methods:

1. spidev_test

spidev_test is a utility for testing SPI devices and is part of the spidev driver.

Installation

Typically, the spidev_test tool is located in the tools/spi directory of the Linux kernel source code. You can get it by compiling the kernel source code:

git clone https://github.com/torvalds/linux.git
cd linux/tools/spi
make

Usage

After compilation, an executable spidev_test file will be generated. Usage is as follows:

./spidev_test -D /dev/spidevX.Y

Parameter description:

• -D specifies the SPI device node, such as /dev/spidev0.0.
• Other parameters like -s set the speed, -b set the word length, etc.

For example, to test the /dev/spidev0.0 device:

./spidev_test -D /dev/spidev0.0

UART

In Linux systems, UART (Universal Asynchronous Receiver/Transmitter) is a common serial communication interface. Various tools and packages can be used to debug UART communication. Here are some commonly used UART debugging tools and their usage methods:

1. Minicom

Package Name: minicom

Installation Method:

sudo apt-get install minicom

Usage:

• Start minicom:

  sudo minicom -s
  

  The -s argument will start the configuration menu.
• In the configuration menu, select Serial port setup to configure the serial port settings. Typically, you need to set the serial device (such as /dev/ttyUSB0) and the baud rate (such as 115200).
• Save the configuration and exit the setup menu. minicom will start monitoring the specified serial port.

2. Screen

Package Name: screen

Installation Method:

sudo apt-get install screen

Usage:

• Start screen for serial communication:

  sudo screen /dev/ttyUSB0 115200
  

  This command specifies the serial device /dev/ttyUSB0 and the baud rate 115200.
• To exit screen: press Ctrl+A, then press K, and finally press Y to confirm exit.

3. CuteCom

Package Name: cutecom

Installation Method:

sudo apt-get install cutecom

Usage:

• Start cutecom:

  sudo cutecom
  

• In the graphical interface, set the serial device and baud rate, then click the Open button to start communication.

4. Picocom

Package Name: picocom

Installation Method:

sudo apt-get install picocom

Usage:

• Start picocom:

  sudo picocom -b 115200 /dev/ttyUSB0
  

  In this command, -b specifies the baud rate, followed by the serial device.

5. Serial Tools

Package Name: serial-tools

Installation Method:

sudo apt-get install serial-tools

Usage:

• Use the stty command to configure the serial port parameters:

  sudo stty -F /dev/ttyUSB0 115200
  

• Use the cat and echo commands for simple serial communication:
  • Receive data:

    sudo cat /dev/ttyUSB0
    

  • Send data:

    sudo echo "Hello UART" > /dev/ttyUSB0
    

These tools and methods can help you debug and communicate with UART on Linux systems. Choose the appropriate tool according to your specific needs and configure and use them accordingly.

CAN

In Linux environments, there are many tools available for debugging the CAN bus. Here are some common debugging tools and their usage methods:

1. can-utils

   • Package Name: can-utils
   • Installation Method:

     sudo apt-get install can-utils
     

   • Common Tools:
     • cansend: Sends CAN frames.

       cansend can0 123#1122334455667788
       

     • candump: Receives and displays CAN frames.

       candump can0
       

     • canplayer: Replays CAN log files.

       canplayer -I log-file.log
       

     • cangen: Generates random CAN frames.

       cangen can0
       

2. socketCAN

   • Kernel Modules: can and can_raw, typically included in the default Linux kernel.
   • Configuration Method:
     • Load the kernel modules:

       sudo modprobe can
       sudo modprobe can_raw
       

     • Configure the network interface:

       sudo ip link set can0 type can bitrate 500000
       sudo ip link set up can0
       

3. python-can

   • Package Name: python-can
   • Installation Method:

     pip install python-can
     

   • Usage:
     • Sending and receiving CAN frames.
     • Example (sending a message on the CAN bus):

       import can
       
       bus = can.interface.Bus(channel='can0', bustype='socketcan')
       msg = can.Message(arbitration_id=0x123, data=[0x11, 0x22, 0x33, 0x44], is_extended_id=False)
       bus.send(msg)
       

These tools can help you effectively debug and analyze CAN bus communication in a Linux environment. Choose the appropriate tool and method according to your specific needs.

Modbus

In Linux environments, there are many tools available for debugging Modbus communication. Here are some common Modbus debugging tools and their usage methods:

1. mbpoll

• Package Name: mbpoll
• Installation Method:

  sudo apt-get install mbpoll
  

• Usage:
  • Read holding registers:

    mbpoll -a 1 -r 100 -l 10 /dev/ttyUSB0
    

    This command reads 10 holding registers starting from address 100 from the slave device with address 1, using the /dev/ttyUSB0 port in RTU mode.