Servo - August 2015

and some new cuts on my hands, I got it in there. Plus, a Y connector was also added so the audio signals would go to both the audio amplifier and the LED color organ circuit.

I wrapped the whole board in a plastic sandwich bag and some electrical tape, so it wouldn't short out inside of the metal can. I also modified the original circuit by adding an output driver stage using TIP 42 PNP transistors. This way, I could drive a lot more LEDs. Beer2D2 got a bit more expensive at this point.

I bought some NTE Electronics’ red, green, and blue waterproof self-adhesive LED strips. At the time, they were $17 each. Plus, I bought some super bright LED modules at Fry’s Electronics for another $50, and yet more NiMh batteries to make another 12 VDC pack to power them.

But wait! That's not all! After the audio controlled blinky light upgrade, I decided to make him selectively autonomous. So, I also added a 7805 5 VDC voltage regulator for sensor power; a 7809 9 VDC voltage regulator for Arduino power; three HC- SR04 ultrasonic PING))) distance sensors — one for each drivetrain housing; and an Arduino microcontroller to read the PING)))

sensors and send the PWM control signals to the speed controllers. I actually wrote the Arduino code while his batteries were charging at RoboGames 2013.

A Very Simple Program

Basically, his simple program is always motivated to move him forward. However, if he gets within three inches of anything that the HC-SR04 PING))) sensors can detect, he will turn right if the left sensor is triggered, or he’ll turn left if the right sensor is triggered. Beer2 will back up if the center PING))) sensor is triggered — all for one second in the desired direction to correct or clear his path.

I also added a 4PDT relay that is controlled with a toggle switch to manually select either the radio or microcontroller. To switch which signal is used, the radio PWM signals are connected to the normally closed side of the relay, and the Arduino PWM signals are connected to the normally open side of the relay. The common pins connect to the speed controller’s PWM input pins. If the relay is off, the robot is in R/C mode; if the relay is turned on, the robot is in Arduino/PING))) sensor controlled autonomous mode. This is and has been Beer2D2's configuration since 2013. I'm sure he would appreciate it if I upgraded his software one of these days.

Our Many Wonderful Adventures Together on the Planet Earth

Beer2D2 and I have been to all of the Bay Area Maker Faires and RoboGames events since 2010. We have also been to countless art,

science, robot clubs, maker spaces, and frequent camping and road trips together. This little guy and I have personally met and entertained literally thousands of folks. I've seen him make a lot of people smile. Watching the looks on little kid’s faces and having More Beer2D2 fans.