Figure 3. Bottom view showing bump sensor
Side view showing servo motor mount.
Open cassette case with battery pack.
50 SERVO 02.2010
The controller is a PIC16F88 loaded with the Tiny
bootloader and programmed using a MAX232a TTL to
RS-232 converter. The circuit board was left over from
another project, and fit quite nicely. Schematics and
artwork for the board can be found on my website
Programming was quick and dirty. I use JAL (Just
Another Language), and Tiny bootloader as my
development platform. I like the JAL compiler because it's
free, and the code is easy to read. The self-programming
capability of the 16F88 coupled with a bootloader make it
very easy to program. The source code for this project is
also available on my website.
After half an hour or so, I had the code working and
the bot was happily bumping into stuff. The code is pretty
simple. I just have the bot go forward until one of the
sensors is tripped, then back up a little and turn in the
opposite direction of the sensor that was bumped. I noticed
Open cassette case showing motors.
Bottom view showing ping pong ball.