Servo - October 2011

' in the initialization code
robot.init_compass

' wherever you need to read the current heading just use
heading := robot.heading

' this assumes you declared the heading variable earlier
' as a WORD or a LONG

LISTING 3. Sample compass reading code.

plot of what is in front of the robot. I have been working on the default firmware for RoboProp, and I thought you might want to see the LIDAR plot generated by one of Robbie's cousins, Marco. Check out Figure 7. roboprop lidar demo

To capture this video, I added a small video output module to Marco and used a USB video capture device to record the live video coming from Marco. The heading is from an HMC6352 and was updating live — as was the radar plot showing the closest object in front of the Sharp sensor.

The rectangles under the radar plot show the status of the left/right/rear virtual bumpers, and the status of the three lines sensors on Marco. The other status displays are currently only mockups. (You can view the LIDAR demo on my You Tube channel at www.youtube.com/mikronauts.)

So, what am I planning to do with Robbie now?

• Explore more "reflex" behavior based on the virtual bumpers.

• Experiment with odometry for course/distance based navigation.

• Integrate a compass heading with the odometry based navigation.

• Add a small speaker so Robbie can make noises to indicate his status.

• Experiment with LIDAR based mapping.

I hope you enjoyed this article series. Please feel free to contact me at mikronauts@gmail.com with any questions you may have about Robbie (or RoboProp). SV

FIGURE 7. RoboProp LIDAR demo.

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