Does LEGO WeDo 9580 really have a sound sensor? Yes and no. The LEGO WeDo basic set comes only with 2 sensors, a "motion" sensor (actually distance sensor) and tilt sensor. No sound sensor. The WeDo Resource Set 9585 also do not come with any sensor at all.
So where does this WeDo sound sensor come from. Actually the computer's mike (microphone) with the software sound input block together can serve as a sound sensor. The program below comprising START block, Display block with microphone input, WAIT block so that the display don't change so fast, and the REPEAT loop
The video below shows the number on the screen display changing with the sound loudness. Note: the values ranged from 0 to 10:
The first WeDo related article in Hispabrick Magazine Volume 016 is titled "An introduction to robotics for the youth with LEGO WeDo" by Diego Galvez It starts with a comparison of WeDo with Mindstorms:
Mindstorms 9797
WeDo
437 pieces
158 pieces
3 motors
1 motor
5 sensors
2 sensors (3 plus computer mike)
1 controller
1 hub
Note that while it is correct to say that the WeDo set has only 2 sensors, actually it can be consider to have 3 with the third one being the computer microphone which can be used as a sound sensor as explained in Sound controlled WeDo motor.
Diego says that WeDo is easier to use plus allows development complex prototypes including a line follower (see video) so it should not be considered as only for kids.
After describing the components (USB hub, motor, tilt sensor, distance sensor, lights (bought separately), the article goes on to describe how the development of prototype can proceed from
Design > Build > Program > Test > Document and share
Video demonstrating voice command MOVE in 41 languages to make LEGO Power Function motor move using LEGO Wedo robotic program. Earlier post with explanation and program at Sound activated motor.
Footnote: pronunciation of MOVE in 41 languages made with Google Translate:
This post will demonstrate how to program a LEGO Power Function motor to move on sound input. We do not need a specific sensor to do this but it will use the computer microphone as the sensor to pick up sound. The Wedo program will consist of a START block, Wait for block, Motor turn this way block, Motor turn for 4 seconds block, Wait block and Repeat block plus a sound input as shown below:
On clicking START, the Wait block will wait for input of sound from the "sound sensor" (computer mike). On hearing sound, the next block turn the motor this way (clockwise) and following block set the motor to turn 3 seconds. The final WAIT 2 seconds block have to be added in to force an interval before the program loop back to the START to repeat. If this is not added, the sound of the motor turning itself will then trigger to motor to move again and the program will go through continuous looping without waiting for the intended sound to start.
See video below. Also see how we can use this to have a Sound controlled car which moves on a sound command eg. clap hands.
Application: Sound controlled car
There is an earlier post about Building computer controlled car. All we need to do to have a sound controlled car is to connect the motor shown below to the computer and setup the above program to make the car move on sound command such as clap of the hands:
Connect motor to computer plus above program to make car move on sound input
This post will show how a motion (distance) sensor can be used to control the speed of a motor and via a crank, the speed at which a goalkeeper moves. The original construction as given by Lego is as shown below (the guidance of parents or grandparents is probably needed for this post):
Lego Wedo goalkeeper game construction as per Lego building instructions
with motion sensor looking different direction from goalkeeper
Look at the direction the motion sensor is looking and the direction the goalkeeper is looking. The motion sensor is looking the wrong way. So we need to modify the setup so that the motion sensor is looking the same way as the goalkeeper - at the striker (ball kicker). Below shows the photo where the sensor is looking at the same direction as the goalkeeper:
The LEGO Wedo software has a neat random number generator to input random numbers into selected programming blocks. This gives parents or teachers a wonderful chance to introduce the concept of random numbers to children. (skip explanations to view demo video)
If your kids have played the Snake and Ladder board game, they would be familiar with the 6 sided dice, but if not, then watch this video and watch how a roll of the dice can generate random number from 1 to 6.
Random number demonstration with numeric screen
The Wedo random number input can reinforce the understanding of random numbers. Setup the following programs (see screenshot below):
To make the car runs even slower, we do a further down gearing. Look at this photo to see how. For a closer look at the downgearing look at the details here.
Lego sets generally come with complete easy to follow building instructions. However, it is much better if children can build new models from scratch without plans. Making a Lego Education Wedo car controlled from the computer with Lego WeDo software or MIT Scratch software is quite easy and hopefully the photos below showing how such a car can be built step by step to build a basic car base which can be added upon to customize can encourage them to create new models from scratch on their own:
Depending on how it is tilted, the sensor will output different values as follows:
Horizontal: 0
Up: 2
Down: 10
Left: 8
Right: 4
The tilt sensor is useful for detecting tilt for various WeDo models like the rocking sailboat or airplane.
A good illustration of how the tilt sensor can be used would be for 2 legged walking robot for sensing tilt and correspondingly move motor or motors in such a way as to keep balance so the walking robot does not fall down.
Lego Wedo models need not be complicated in order to learn how to use those Wedo programing blocks. It may just be the WeDo motor fitted with a "propeller" just to show the direction with the motor is turning like what is shown below:
Simple model to learn how Lego Wedo programming
The start block can be activated by mouse clicks or by pressing keyboard keys. Below show 2 WeDo programs activated by up or down key presses on screen simultaneously:
Here is a little experiment with the Lego WeDo robotic set using the Start block, Motor this way block, Sound block, Motor stop block with the number block controlling the sound.
Try changing the number and observing what happens. You will notice that the motor turns for as long as the sound is playing, then stop.
Try replacing the number block with the dice (random) block.
Also try clicking on the Motor this way block. Notice that the block then change to Motor that way block, the direction changed.
Here is a motor of a simple setup just to show how the motor is turning. Motor connected to hub, hub plugged into computer USB port:
