Science Buddies: "Ask an Expert"

Okay so my project is a motion activated guard robot. When I turn on my robot the sensor is suppose turn on and turn red and the wheels spin. Then wait around 40 seconds for the sensor to calibrate. When it does the wheels are suppose to stop. When i turn it on the sensor turns on and the wheels turn, and after 40 seconds the sensor turns off, but the wheels slow down but do not turn off. I LITERALLY HAVE TRIED EVERYTHING! If their is any suggestions it would be really helpful.

- Mayers

Hi Mayers -

Did you purchase the EXACT parts linked on the Materials tab for the project, or did you get them somewhere else (like Radio Shack)? I don't remember the sensor taking an entire 40 seconds to calibrate, so that makes me wonder if you have a different sensor.

It's hard to help without seeing your circuit - any chance you can post some pictures of your breadboard? Try to post a few pictures from different angles, including top-down, and make sure everything is in focus.

-Ben

I bought my materials for my breadboard and to build the cart from SparkFun Electronics. But on the directions it says that i needed to buy the sensor from Jameco electronics, NOT from sparkfun because the PIR sensor from sparkfun does not do the functions that is wanted to complete this engineering project. I will for sure send pictures it might be a while though. I have gotten all of the science teachers in Middle school to look over the wiring and we found some mistakes but adjusted them.

Thanks
Mayers

Ok, if you are getting in-person help looking for wiring mistakes, that will be much better than posting pictures here. It's a lot easier to see mistakes in person. If you don't have experience working with a breadboard, it can be pretty easy to make mistakes. Having just a single wire off by one hole can prevent the circuit from working properly. Good luck with your troubleshooting.