Over the five classes, we were able to create motors that react to sound. In the process, we learned how to program, how to connect motors, microphones, and experienced an engineering process.
Overview of the design process:
Step 1: Research
We looked over a wide range of websites, tutorials, that creates similar products to our initial idea. After evaluating the pros, cons, and doability of the examples, we decided to use an Arduino Uno board, a microphone, and motors to create our final product.
Step 2: Microphone -> Arduino
Our first step was to connect our sound sensor to the Arduino board. After asking teachers and doing our own research, we were able to understand the relationship between the microphone to successfully connect the two. We coded the Arduino board so the built-in LED light lights up when a sound is detected from the microphone.
Step 3: Motor -> Arduino + Car Build
During this step, Sophie and I split up the work. Sophie worked on building the car model and working on how to connect the motor to the wheels while I worked on connecting the motor controller (motor shield) to the Arduino board. After trying with different materials, we decided to build a lego car as it is the strongest and most convenient. Our initial idea was to use gearwheels to move the car (See picture above). We were also able to generate a code that allowed the motor control to react when a sound is detected from the microphone.
Step 4: Debugging and refinement
When we were putting the two parts of our product together (The car and motor + Microphone Arduino), we immediately realized many issues. First of all, a single motor was too weak to move the car, the gearwheel easily gets stuck. To resolve this issue, we decided to add another motor to power the front wheels and changed the code so the motors are at their highest speed. Secondly, the microphone detects the sound of the motor; thus, it never stops. We tried alternating the sensitivity of the microphone and changing parts of the code. Ultimatley, we chose to ask Mr. Beatty for help, where we changed the input from a digitalRead to an analogRead.
Step 5: Finalizing & Reflection
Disappointingly, we were unable to get the car running as we did not have enough time remaining and some parts fell apart last-minute (wires fell out), which was the major weakness of our product. However, our final product was a sound-controlled motor where someone can speak into the microphone and the motor will run until the sound is no longer detected. If the opportunity is given, we would like to fix the small errors and test whether the car is movable. We were unable to meet our initial design goal that is to make a “sound-powered car”. Our final product shows energy conversion from electrical energy to kinetic energy that is triggered by sound. The Arduino Uno board is powered by a energy source such as a laptop or a charging bank whilst the motors are powered by batteries.
Our final product can be used to create many other toys such as a sound-controlled windmill or fan which can have a targetted audience of children above the age of 7 and under the age of 16. Despite the fact that we were unsuccessful in creating the product we initially had in mind, I was proud that we challenged ourselves to make something creative and different.