Skip to main content

Robot Remix #5 - HUNGRY HIPPO

Robot Remix #5 - Hungry Hippo
By Joe Meno


Are you hungry for a brand new game?

Hungry Hippo is a cross between LEGO MINDSTORMS 31313 and LEGO Technic 42076.  The two sets are combined to recreate an electronic version of the very popular children's game called "Hungry Hungry Hippos." The goal of the game is to see which player "eats" the most balls.

In this MINDSTORMS version, a single player plays against the EV3.




Design Idea:

Joe came up with the idea while looking at a McDonald's Happy Meal version of a Hungry Hungry Hippos toy his niece was playing with. He also wanted his remix idea to be interactive game with a a user.  Looking at the parts in the two sets, he was knew he could create "hippos" in different colors and the use the flat panels for the bottom of the game board.

Joe started with a sketch of his design. He did have to alter the design from a 4-player to a 2-player game (one user and one computer player). He also moved the ball lift to the edge. As a result, the EV3 moved to the front and the touch sensor was used as a controller.

How it Works:

There are two players - the EV3 and the user. Each controls a "hippo". The EV3 continually runs the white hippo.  The red "hippo" player hits the touch sensor to make the mouth move.  By having a rail beam where the head rests, the motor mechanically raises and lowers the head with each revolution. A ball lift is run by a medium motor that is activated by the score sensors (infrared and color).

At the beginning of the game, the score to win is set by using the EV3 buttons to go higher or lower than the default number of 5. After that, the balls are lifted and released on to the game board.

When the EV3 (white hippo) eats a ball, it falls down a slope and is detected by the IR sensor (set to proximity). When the sensor is tripped, there is a delay and then a ball lift command sent to the lift motor. After the ball lift is activated and the score is recorded. When the user (red hippo) eats a ball, it falls down a slope and is detected by the color sensor (set to red to match the ball color). When tripped, the program cycles just like it does for the white hippo. The ball feed can be activated by the user during the game by pressing the center EV3 button - this is done to keep all the balls in play.

The biggest challenge in this design was the dimpled balls in the 31313 set. Building the lift took some trial and error, but Joe was able to make a single ball feed. However, the red balls in the MINDSTOMRS set are not truly round - there is a dimple that is large enough to stop the ball's motion. The result was that the balls would get trapped under the game board from time to time. This was fixed by manually pushing the ball to the ball feed.


 




Building Instructions and Code:

If you want to build one too, building instructions and code are available for download.

Popular posts from this blog

MINDSTORMS Retires!

2023 is the 25th Anniversary of the MINDSTORMS brand. For 25 years, MINDSTORMS has educated and inspired a generation of robot builders, both children and adults. Unfortunately, the LEGO Group decided to end the line on December 2022. Many ROBOTMAK3RS have been passionately involved with the development of MINDSTORMS through the MUP and MCP programs. Even with the newest Robot Inventor line, several ROBOTMAK3RS were invited to submit additional bonus models that were included in the official app. Regardless of the retirement of a major LEGO robotics product line, ROBOTMAK3RS continue to MAKE-SHARE-INSPIRE using all LEGO robotics platforms available to us. Here is the official statement from LEGO. Since its launch in September 1998, LEGO MINDSTORMS has been one of the core ‘Build & Code’ experiences in the company’s portfolio, carrying with it significant brand equity and becoming a stand-out experience for the early days of consumer robotics and leading to current Build & Code

Celebrating 25 Years of MINDSTORMS

In celebration of the 25th Anniversary of MINDSTORMS, we take a trip through history. Please also visit ROBOTMAK3RS Community every week as we highlight different projects all through 2023 in celebration of the anniversary. Some of the early history is based on the content shared by  Coder Shah  in our  MINDSTORMS EV3 Community Group . Some of the text and links may have been edited from his original posts for consistency and clarity.  1984 - Kjeld Kirk Kristiansen watched a TV program called "Talking Turtle," where MIT professor Seymour Papert demonstrated how children could control robot "turtles" using LOGO, a programming language he developed. 1988 - The collaboration between MIT and LEGO resulted in LEGO TC Logo in 1988, which allowed students to control LEGO models using computer commands. The video shows Papert demonstrating TC Logo. 1990 - LEGO TC Logo was hampered since the robots you built had to be tethered to a personal computer. LEGO and MIT

Celebrating MINDSTORMS with a Remix Part 1

In honor of the 25th Anniversary of MINDSTORMS, we asked ROBOTMAK3RS to combine a LEGO set of their choice with a MINDSTORMS set. Here is what these five ROBOTMAK3RS came up with.  MINDSTORMS Chess Assistant by Arvind Seshan Overview: When you are new to chess, it can be a challenge to remember which pieces go where. Now, you can use machine learning and LEGO MINDSTORMS Robot Inventor to build a tool to help you learn where all the chess pieces go on the chess board. Sets used: LEGO® Iconic Chess Set (40174) and MINDSTORMS Robot Inventor (51515) Review: I really like how the chess set base can store all the pieces underneath and that the board neatly splits in half for handy storage. The chess pieces themselves are very sturdy and well built. My only criticism is the building of the box itself. It was quite difficult to see what pieces to use and since the entire box is made mostly of thin plates, it took a lot of time and patience. I would have liked the storage area to be sliding dra