Sadly, Dr. E’s WeDo Challenges and Dr. E’s MINDSTORMS Challenges will no longer be posting new challenges. However, both websites will remain up so that you can continue to access the previous challenges and all of the wonderful submissions. Thank you to LEGO Education and to the Center for Engineering Education and Outreach at Tufts University for their years of support (and thank you to LEGO for their amazing robotics platforms). During the six years of WeDo challlenges and five years of MINDSTORMS challenges, we received almost 1000 submissions from around the world. The two websites had a total of 1266 registered users from 57 different countries. We were truly a global community! We have always been inspired and energized by the creativity and innovation shown by the Dr. E's Challenges community; while new challenges won't be posted moving forward, we hope that you continue doing awesome stuff in your homes, clubs, and classrooms and that you continue to share your projects with the world! Collaborating with all of you has been a joy and an inspiration. Thank you, The folks at Dr. E’s


Waiter bot is a robot built with LEGO Mindstorms using EV3 brick, a color sensor and a touch sensor to carry snacks from kitchen to living room or any other place really as long as there is a black line for it to follow. Its programmed to follow a black line from the kitchen all the way into the living room. That involved going through 3 diferent floors with 3 different colors to compare against black including brown which is a bit close to black. To stop the bot anytime or anywhere, a touch sensor is added. By default, when the program is run, the bot starts comparing colors and stays close to black line. If the gear attached to the touch sensor is touched, it stops.

In order to make the 90degree curves, its programmed to move both wheels with one moving forward and another moving slightly backward. When it detects black, it steers right and when it detects other color in comparison, it moves left so it always stays on line.


Waiterbot, 1.0 out of 1 based on 1 rating


  1. williamchurch17

    Hello Manu — congratulations on completing your kitchen helper. Delivery robots of this type are used for many applications. Taking on different floor colors as you did is a part of the real world challenge many robots face. Carrying snacks from the kitchen to others rooms is a fantastic job for a robot! I am sure that the people who received the snacks from the robot enjoyed the results of your hard work!

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