This page reviews issues you may encounter and should be aware of in order to avoid problems. It's important to read over this page and familiarize yourself with its content before starting a class using AERobots. If you encounter specific difficulties, you may find explanations and suggested fixes below.
An important thing to remember is that AERobot is by design a very simple device. On the plus side, this lets it be very inexpensive while still having a range of capabilities and supporting a variety of activities. The downside is that it's very limited in some ways, which, if you're not expecting it, can be frustrating. For instance, the movement using vibration motors requires going through a calibration procedure every time the robot is moved to a different surface, and can be erratic (especially when trying to get the robot to move in a certain way without using any sensor feedback).
A surprising variety of apparent problems can be improved by recalibrating the robot's motors. The software page describes the procedure. The robot can need recalibrating when it's moved to a new surface, when the battery level changes too much, when decorations are added, etc. Symptoms of poorly calibrated motors can range from the robot hardly moving to it moving in the opposite direction from what you expect. When in doubt, calibrate!
Make sure the battery is charged when you calibrate the robot. If you calibrate it with a low battery, it'll behave poorly once recharged and require re-calibration.
In general, in sessions with the robot, it's a good idea to keep it plugged in whenever you're not running it. Depending on how fast you run the motors, the battery can run down from a full charge in less than an hour, and take longer than that to charge from a depleted state. Be aware that when computers go to sleep, some continue to provide power to their USB ports and some don't, so if you have the latter situation you could plug your robot in without realizing it's not actually charging.
As with other rechargeable batteries, it's best to try to keep the battery charged when possible (including storing it in a charged state), and not let it get completely discharged. If it's kept in a low-charge state for a long time, it may become damaged and not charge again effectively (or at all). If you need to replace the battery, take note of two things: (1) Replace it with an identical battery. (For instance, a non-rechargeable battery won't work.) (2) Use a plastic tool to help remove the battery -- using a metal tool can cause a short circuit on the exposed circuit board and damage the robot permanently.
When using the line sensors for line-following, you need to perform a separate calibration for the sensors, in addition to the motors (see the software page). Changing the light levels in the room may make it necessary to recalibrate the line sensors. The sensors are sensitive to brighter ambient light, especially sunlight; for best results, cover any windows in the room, and turn down artificial lights. As with motor calibration, make sure the battery is charged.
Sometimes, when you plug the robot into the computer and try to send it a new program or a calibration command, the command will fail and the program will give you an error as if there's no robot connected. (Windows may report the robot as an "Unknown Device" in this situation.) This happens especially often for calibration commands. There are three things to try when this happens: (1) just send the command again; (2) press the robot's power switch; (3) unplug and replug the robot. It'll work within a few tries. We're aware of this issue and working on a software patch to improve it.
Because the robot has an exposed circuit board, it's vulnerable to short circuits and damage if it comes into contact with conductive materials. Keep it away from liquids and metal objects (even paper clips). Similarly, if you're in a situation where static buildup is likely (e.g., a dry, cold day in a carpeted room), try to discharge yourself before handling the robot.
We plan to set up an online forum for AERobot users to discuss their experiences and ask questions. This community may be the fastest way to get questions answered (see the next point)...