Musibike - Innovative Electronic Instrument

Hi!

The Musibike project was executed as part of my electronics engineering degree and I because all the help I have been getting from Instructables I wanted to share it with all of you. The First Time Author contest was the excuse I needed!

My main goal is to share with you how the project was developed and all the work that is behind building something (as many of you already know).

The Musibike is a programmable electronic instrument that can be controlled via DMX to play your favourite (5 strings) songs.

Some pictures have some Spanish in them, apologies for that.

Keep scrolling to see more!

A team of 4 students was formed and we had to think about the idea of the product we wanted to create.

Key factors that we decided:

1. Electronic instrument
2. Chord instrument
3. Automatic and programmable
4. A mix between a guitar and a bike

The idea was cool, but we needed a more detailed schema before starting.

Our key elements in this case were far more detailed:

1. Resonance box: If we want to hear the sound with the motor spinning, we have to amplify the sound from the string.
2. Motor system: The wheel will have to spin at a relatively slow speed (1 cycle per second approximately)
3. Pick system: We intend to use a solenoid to interact with the string, but it has to be fast and precise
4. Motor adapter: So we can attach the motor to the pedal axis
5. Vision sensor: This way we can detect the exact position of the wheel while it is spinning

Next, we decided to 3D model our idea, because it is really helpful when landing an innovative solution.This way we could work in all aspects of the project at the same time, because we were aligned on how the final Musibike would work.

We used a lot of recycled materials. An old bike from my sister, a wooden closet from the bin, etc.

From there we started attaching all the mechanical parts to the base. You can see that we had to design a small 3D printed part so we could attach the motor to the pedals side of the Musibike.

Here are a few recommendations when developing electronics projects with custom designs and PCB:

1. Create your block diagram schema
2. Transform the block diagram into your schematic with details on the component side
3. Create your PCB with an easy-to-use tool (I used Circuitmaker because it was a collaborative project).

You can see that every aspect of the Musibike was electronically controlled, and timing was crucial.

Here I wanted to share with you the detailed schematic that we created for the Musibike.

As you can see, there are a lot of connectors because the devices were far away from the PCB.

List of parts:

• Motor system
• Optic sensor
• Microcontroller
• Solenoid
• DMX controller
• Power wiring

On the hardware part it wasn't difficult to find the right devices:

• Optical Sensor: Grove Line Finder http://wiki.seeedstudio.com/Grove-Line_Finder/
• Motor: 12V 60rpm
• Solenoid: 12V lineal actuator
• Microcontroller: Atmega328P
• Power: 7805 IC

The rest are pretty normal components such as resistors or capacitors.

The firmware is pretty simple. We have 2 main loops going on (one is interruption-based).

1. Main loop: It reads the DMX channel to receive the string to be played. When the nextString equals the stringToPlay, we activate the solenoid for a certain amount of time to play the tone. Then we start over again.

2. Interruption loop. Each time the vision sensor detects a new string passing through, it counts the nextString. We know there are 5 strings, so we start over again when the count is 6. This way we always know which one is going to be the next string.

Attached is the full program

Here you can check out the final result.

I hope it was an interesting and readable instructable.

If you like how the project was organized, please vote me for the First Time Author Contest!!

Thank you in advance :P