Andrea Zoppi wrote something. This is links to the work. Some talk has
gone on about it in this sig http://www.ros.org/wiki/sig/Embedded.




 The code is available at https://github.com/openrobots-dev/uROSnode under
a 2-clause BSD license.

It is still an alpha release (0.1.3) at the moment, but it seems to be
solid enough to handle a clone of the "turtlesim_node", under ROS Groovy,
with a few known bugs (being fixed).
A copy of the documentation is available at
http://dl.dropbox.com/u/2771793/uros/doc/html/index.html.


On Sat, Apr 27, 2013 at 4:24 AM, Peter Rudolph <semael23@gmail.com> wrote:

> Hi Everyone,
>
> Due to having no Arduino, but willing to test the connection from an
> embedded system to a ros-host, i have written a message generator,
> generating C message-header files compatible to standard ros_serial
> messages. Also I have written a small version of ros lib, containing types
> and function mechanisms to build up a simple node on an embedded system, in
> the same style its written on host-machines.
>
> Following Code is part of my example project running on a
> STM32F3Discovery, containing accelerometers, magnetometers and gyroscopes,
> it represents a ROS-IMU sensor. The board is available for 15-20$ I think,
> me got it from embeddedWorld fair this year.
>
> int main(void)
> {
>   /* init hardware */
>   hardwareInit();
>   /* initialize IMU */
>   imuInit();
>   /* initialize ROS, namespace "imu_sensor*/
>   rosInit("imu_sensor");
>   /* get pointer to global nodehandle */
>   rosNodeHandle_t* nh = rosNodeHandle();
>   /* setup ROS IMU message */
>   Imu_t imu_msg = rosCreateImu_t();
>   /* advertise imu msg */
>   rosPublisher_t *imu_pub = nh->advertise(&imu_msg.mh, "/Imu", 512);
>   /* set frame id */
>   imu_msg.header.frame_id = "/base_link";
>   /* enter loop */
>   while (rosOk())
>   {
>     /* update IMU data */
>     imuUpdate();
>     /* set data to imu message */
>     float* acc = imuGetAcc();
>     float* mag = imuGetMag();
>     float* gyr = imuGetGyr();
>     float* ori = imuGetOrientation();
>     imu_msg.angular_velocity.x = gyr[X];
>     imu_msg.angular_velocity.y = gyr[Y];
>     imu_msg.angular_velocity.z = gyr[Z];
>     imu_msg.linear_acceleration.x = acc[X];
>     imu_msg.linear_acceleration.y = acc[Y];
>     imu_msg.linear_acceleration.z = acc[Z];
>     imu_msg.orientation.w = ori[W];
>     imu_msg.orientation.x = ori[X];
>     imu_msg.orientation.y = ori[Y];
>     imu_msg.orientation.z = ori[Z];
>     /* set timestamp */
>     imu_msg.header.stamp = rosTimeNow();
>     /* publish message */
>     imu_pub->publish(&imu_msg);
>     /* spin nodehandle */
>     rosSpinOnce();
>     /* sleep 50 milliseconds */
>     rosSleep(50);
>   }
> }
>
>
> Library code and generated code are at least C99 compatible. Heap size
> used is determined by in-/out-buffer lengths like its done in standard
> ros_serial. Input is bufferd by a fifo-queue and processed via rosSpin() or
> rosSpinOnce() function (same way ros_serial does). Therefor the code could
> be usable for any controller understanding C, having a U(S)ART and at least
> 4K memory.
>
> Currently I'm trying to bring up a FreeRTOS-ROS system, to have another
> way to implement sensors or something else.
>
> Now my question is, what shall i do? Put it into ros_serial? Or shall i
> make a new ros_embedded package? Or are there already plans to build up an
> embedded distribution on RTOS systems, like FreeRTOS?
>
> Regards,
> Peter
>
> _______________________________________________
> ros-users mailing list
> ros-users@code.ros.org
> https://code.ros.org/mailman/listinfo/ros-users
>
>