One problem I had was making object detection work.
The first thing I tried was using an Infra Red LED and an IR sensor. I was going to make a circuit which would make the robot back up and turn when a reflection was sensed, but house lights messed it up because they let out Infra-Red light. Next I made lego whiskers. I have one circuit for each wheel which, when the input is connected to +, will change the direction of the wheel for a few seconds, and then change it back to its origonal direction. The amount of time each wheel reverses is different. This makes it so at first, when they were both spinning backwards, the robot backs up. When the wheel which reverses for the shorter amount of time starts spinning forwards again, the robot turns. After about a second, the other wheel starts
spinning forwards, and the robot drives forwards again. I
made the lego whiskers, and then connected them to each
other, so it didn't matter which one was pressed. Then I
connected them to the inputs of the circuits controlling
the wheels and also to +. I turned it on and pressed a
whisker, and both wheels started going backwards. So far,
so good. But then, both wheels started going forwards again.
They were supposed to do that at different times. I found
out what the problem was. It was that connecting both
circuits to the whiskers had also connected them to each
other. After trying a couple things, I found out that all I
needed was a couple of diodes to make it so the circuits
didn't affect each other.
