QED Mark II
Last year I helped my daughter, Belle, put a bot together for AVC 2013. Belle named her bot QED after the Latin phrase quod erat demonstrandum, which roughly translates as "that which was to be demonstrated." However, for reasons known only to my daughter, QED takes the form of a turtle and also happens to serve as Mayor of Turtletown. Here's a photo of QED on the starting line at AVC 2013:
Click for larger view
Under the shell, QED was sort of thrown together at the last minute from various custom PCBs I'd designed for prototyping purposes. These included a version of the Arduino Leonardo I repackaged into a form factor that lets it fit on the end of a solderless breadboard, an Adafruit Ultimate GPS module, a Pololu Mini IMU I'd used in an earlier version of my robot, Johnny Five, and a small, custom I/O breakout board I'd designed to go with the breadboard-friendly Leonardo. Here's a photo that shows QED's original guts:
Click for larger view
The code running QED was a simplified version of the Arduino code I'd developed for Johnny Five, and also uses with the same, Java-based waypoint input and management software I'd written for J5. Belle's Engineering class at High Tech High in San Diego had built a few projects using the Arduino, so Belle understood the basics of the hardware I put together for her, even if some of the more advanced concepts required a bit of explaining. However, she took to the task of route and waypoint planning like a duck to water and, once we had he hardware up and running, she insisted on handling all the details of the actual competition on her own and, while QED had some issues during the 3 actual race events, QED managed the amazing feat of going all the way around the course during the free for all that is the "mass start" event at the end of the race day. All with no help from Dad. I could not have been prouder.
Giving QED Some New Guts
As the story of our adventures at AVC 2013 spread around our family, my brother, Ken called me one day and wondered if I could help his daughter, who's a year younger than Belle, put together a car for AVC, as she's shown some interest in an engineering career. So, in consultation with Belle, I came with a more refined designed for QED that's based around an Arduino Mega board combined with a custom LCD shield I designed for Johhny Five and a small extender PCB to hold a Pololu Mini IMU Rev2, the same GPS module Adafruit uses in their Ultimate GPS breakout board and some additional circuity that allows the GPS to stay powered even when changing, or charging batteries in the bot. Here's photo that shows these two board mounted on top of an Arduino Mega:
Click for larger view
I designed the LCD using through hole parts, so Belle and her cousin, Clarissa, could solder in all the parts and learn a bit about electronics. Belle's an old hand at soldering, but this was Clarissa first time building anything electronic. But, under Belle's excellent tutelage, Clarissa got the board and assembled and working with only about an hour spent, total. The 2nd board uses mostly surface mount parts, so I put these together for the girls. For Clarissa's bot, I also managed to purchase the same Team Associated 1/18 scale chassis we used for QED on eBay, so this let's me use nearly the same settings for ESC and servo control, which greatly simplified the process of getting a 2nd bot up and running. Here's a photo showing the chassis with all the electronics mounted and hooked up (this is actually the chassis for QED, as Clarissa's bot has white rims):
Click for larger view
The mechanism to the right of the PCB stack is Belle's idea for AVC 2013. Last year QED seemed to navigate fairly well, but happened to get stuck behind behind another bot as well as some of the hay bales. So, she reasoned that she needed to add some simple form of collision detection and then program the bot to at least try to back up and try again to navigate around the obstacle. This mechanism is still under design, but she may choose to use attach QED's head to the bumper assembly so that it can serve as the obstacle detector.
So, watch out! Team Short Circuit now has three robotic members and we'll be gunning for you at the upcoming AVC 2014.