overo-arduino-i2c

Some example programs for Gumstix Overo to Arduino I2C communication.

There is some more documentation here Gumstix to Arduino using I2C

The Arduino is a more flexible I2C device because it can be either a master or slave device on the I2C bus. Because of the Linux driver, the Overo can only be an I2C master.

There is an Arduino sketch under the arduino directory that implements the Arduino side of the test programs in this project. You should load that first. It establishes the Arduino as a slave device at address 0x10.

On the Gumstix side you have a choice of C, Perl or Python.

For the C program, you can build it either on your host workstation using the OE cross-compiler tools using the Makefile provided then copy the resulting overo-i2c executable to the Gumstix. If you have C development tools on the Gumstix, then you can use the Makefile-native make file and compile it there.

For Perl or Python, just copy the perl-overo-i2c.pl or python-overo-i2c.py script to the Gumstix and run it. Of course you need Perl or Python on the Gumstix first.

There is an OE image recipe called dev-image.bb in the recipe directory of this project that will build a minimal Overo image with all the dev tools you need to run the examples. Copy it to your workstation and build it with bitbake or just use it to figure out what to add to your image.

Usage

Assuming you copied the following files to your Gumstix

root@overo:~# ls
Makefile  Makefile-native  overo-i2c.c	perl-overo-i2c.pl  python-overo-i2c.py

To build the C program

root@overo:~# make -f Makefile-native
gcc -Wall overo-i2c.c -o overo-i2c 

And to test it

root@overo:~# ./overo-i2c test-me
Sent: test-me
Received: TEST-ME

For the Perl program

root@overo:~# ./perl-overo-i2c.pl perl-test
Sent: perl-test
Received: PERL-TEST

And the Python program

root@overo:~# ./python-overo-i2c.py 
Sent: hello
Received: HELLO

To build the C program on your workstation using the OE cross-compiler

~$ cd overo-arduino-i2c/overo-c
~$ export OETMP=/oe5 [optional if you have a non-standard OETMP]
~$ make
/oe5/sysroots/`uname -m`-linux/usr/armv7a/bin/arm-angstrom-linux-gnueabi-gcc -Wall -I /oe5/sysroots/armv7a-   angstrom-linux-gnueabi/usr/include -L /oe5/sysroots/armv7a-angstrom-linux-gnueabi/usr/lib overo-i2c.c -o overo-i2c

Then copy the overo-i2c executable to your Overo.