carobotics
The robot is almost complete and not a moment too soon. A few things need to be tweaked and the lift for scoring baskets needs to be complete. Those things should be done in a couple of hours, and then we just need to add the electronics and assuming all goes well, we should be done with the robot. But knowing this team, there will probably be problems anyways.
We had three designs that were being prototyped, two were dumpers and one was a shooter. The voting was close so our mentors decided that we would do two manipulators, a shooter and a dumper. Now we are coming up on the deadline and we still aren’t done, close, but not done.
This weekend we wired up our ultrasonic sensors, which will be used to stop the robot once it is close enough to the scoring pegs in the autonomous period. We ordered two LV-MaxSonar-EZ4s from MaxBotix and wired them up in “chaining mode.” (Maxbotix provides instructions here [PDF].) In this configuration the two (or more) sensors take turns sending out ultrasonic pulses, preventing interference between the sensors. We tested this out on a breadboard and discovered that the sensors do interfere with each other when used without the chaining mode, at least when they are within a few inches of each other. In chaining mode, however, they do not interfere with each other.
After wiring the sensors, we discovered that one of them was getting burningly hot just a few seconds after turning on. The culprit seems to be the PIC microcontroller on the EZ4′s PCB. We contacted Maxbotix and they very quickly sent us a replacement.
The FIRST® Robotics Competition is a high-school robotics competition that inspires students to pursue engineering and teaches them about the rewards and challenges of working together under pressure.
