I2C

Introduction

The Robostix is a board based around an Atmel AVR processor. Robotics microcontroller runs code as a stand-alone board or connect through 60-pin connector to any gumstix platform for expanded power and connectivity. Besides Hirose 60-pin connector it contains following connections:

• I2C Bus
• SPI

Installation

• create new modules. From the Linux Kernel Configuration:

1. I2C support
2. I2C device interface
3. Intel PXA2XX I2C adapter
4. Intel PXA2XX I2C Slave comms support

• create modules

cd gumstix-buildroot/build_arm_nofpu/linux-<the version of linux you're using>

make ARCH=arm CROSS_COMPILE=`pwd`/../staging_dir/bin/arm-linux- menuconfig
make ARCH=arm CROSS_COMPILE=`pwd`/../staging_dir/bin/arm-linux-

• if modules were chosen as a built-in it's necessary to recompile the kernel

../../make

and replace the filesystem image on the gumstix

• add modules, if not built-in:

#modprobe i2c-pxa
#modprobe i2c-dev

Tango Device Server settings

#---------------------------------------------------------
# SERVER I2C/gumstix, I2C device declaration
#---------------------------------------------------------
I2C/gumstix/DEVICE/I2C: "gumstix/i2c/1"

Device Server

Commands

• ReadPackets
• WritePackets

Implementation

• download program for interacting with I2C devices from SVN (gumstix:gumstix)
• add header

#include "i2c-dev.h"

• ReadPackets
• WritePackets

Using the Gumstix and Robostix together

If you would like to boot a robostix/gumstix combination with no serial console plugged in, then you should add a 10k resistor between pins 3 and 4 on the "gumstix" connector. Failing to do this will cause the gumstix to drop into u-boot and to not boot the gumstix.