ODROID XU4 Custom Drivers

Author: Rommel Samanez (rsamanez)
Platform: ODROID XU4
OS: Ubuntu Linux 18.04 LTS
Sensor: MaxBotix I2CXL-MaxSonar-EZ (MB1242)
Interface: I2C via ODROID IO Expansion Board

📘 Overview

This repository provides a custom Linux kernel driver (ioboard-mb1242.ko) for interfacing the MaxBotix MB1242 ultrasonic sensor with the ODROID XU4 single-board computer. The MB1242 communicates over the I2C protocol and offers reliable distance measurements ranging from 20 cm to 765 cm with 1 cm resolution. This driver facilitates seamless integration of the sensor with the ODROID IO Expansion Board, enabling accurate distance sensing for various applications.

⚙️ Features

• Distance Measurement: Retrieves distance data from the MB1242 sensor via I2C.
• Address Configuration: Includes a utility (mb1242-change-address) to modify the sensor's I2C address.
• GPIO Access: Provides guidelines for configuring GPIO access without root privileges.
• System Integration: Offers instructions for compiling and loading the kernel module on Ubuntu 18.04 LTS.

🛠️ Installation

1. Compile the Kernel Module:

   make -C /lib/modules/$(uname -r)/build M=$(pwd) modules

2. Install the Module:

   sudo cp ioboard-mb1242.ko /lib/modules/$(uname -r)/kernel/drivers/
   sudo depmod

3. Load the Module and Configure I2C:

   sudo modprobe i2c-gpio-custom bus0=10,33,23,10,10
   sudo modprobe ioboard-mb1242
   echo ioboard-mb1242 0x70 | sudo tee /sys/class/i2c-dev/i2c-10/device/new_device
   echo 1 | sudo tee /sys/class/i2c-dev/i2c-10/device/10-0070/enable

4. Read Distance Data:

   cat /sys/class/i2c-dev/i2c-10/device/10-0070/distance

🔧 Changing the Sensor's I2C Address

The default I2C address of the MB1242 sensor is 0x70 (112 in decimal). To change it:

sudo ./mb1242-change-address 112 100

Replace 112 with the current address and 100 with the desired new address.

🧰 Additional Tools

• I2C Tools Installation:

  sudo apt-get install i2c-tools

• Detect I2C Devices:

  sudo i2cdetect -y -r 10

🔐 Configuring GPIO Access Without Root

To allow non-root users to access GPIO:

1. Create UDEV Rules:

   Add the following to /etc/udev/rules.d/10-odroid.rules:

   SUBSYSTEM=="gpio", KERNEL=="gpiochip*", ACTION=="add", PROGRAM="/bin/sh -c 'chown root:gpio /sys/class/gpio/export /sys/class/gpio/unexport; chmod 220 /sys/class/gpio/export /sys/class/gpio/unexport'"
   SUBSYSTEM=="gpio", KERNEL=="gpio*", ACTION=="add", PROGRAM="/bin/sh -c 'chown root:gpio /sys%p/active_low /sys%p/direction /sys%p/edge /sys%p/value /sys%p/uevent; chmod 660 /sys%p/active_low /sys%p/direction /sys%p/edge /sys%p/value /sys%p/uevent'"

2. Add User to GPIO Group:

   sudo usermod -aG gpio odroid

3. Automate GPIO Export on Boot:

   Add the following line to /etc/rc.local before exit 0:

   sudo -u odroid /usr/local/bin/gpio export 173 out

   Replace 173 with the desired GPIO pin number.

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Controladores Personalizados para ODROID XU4

Autor: Rommel Samanez (rsamanez)
Plataforma: ODROID XU4
Sistema Operativo: Ubuntu Linux 18.04 LTS
Sensor: MaxBotix I2CXL-MaxSonar-EZ (MB1242)
Interfaz: I2C mediante la Placa de Expansión IO de ODROID

📘 Descripción General

Este repositorio proporciona un controlador personalizado del kernel de Linux (ioboard-mb1242.ko) para la integración del sensor ultrasónico MB1242 de MaxBotix con la computadora de placa única ODROID XU4. El MB1242 se comunica a través del protocolo I2C y ofrece mediciones de distancia confiables que van desde 20 cm hasta 765 cm con una resolución de 1 cm. Este controlador facilita la integración del sensor con la Placa de Expansión IO de ODROID, permitiendo una detección de distancia precisa para diversas aplicaciones.

⚙️ Características

• Medición de Distancia: Recupera datos de distancia del sensor MB1242 a través de I2C.
• Configuración de Dirección: Incluye una utilidad (mb1242-change-address) para modificar la dirección I2C del sensor.
• Acceso a GPIO: Proporciona pautas para configurar el acceso a GPIO sin privilegios de root.
• Integración del Sistema: Ofrece instrucciones para compilar y cargar el módulo del kernel en Ubuntu 18.04 LTS.

... (contenido continúa igual como en la sección en inglés, adaptado al español)