Arduino Automatic Trombone Tuner

Introduction: Arduino Automatic Trombone Tuner

This project is an automatic trombone tuner. A very fast and effortless way to tune a trombone. This project can and will be adapted to other instruments, so don't worry if you don't play trombone. Also, this project is still developing so if you have ideas or suggestions I would love to hear about them.

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Step 1: Parts

Here's what you will need:

  • A Trombone (contact me if you want me to help you adapt this to other instruments) also the tuning slide needs to be easy to move, and there needs to be a place for the servo to sit (see step 4)
  • A Powerful Servo (with this project the bigger the better, I am using a MG995)
  • An Instrument Tuner (must have flat and sharp indicator LED's) (I'm using a Fender FT-100)
  • 4 Photo Resistors
  • 4 10k ohm Resistors
  • 1 1k ohm Resistor
  • 1 Micro-controller (I am using an arduino uno)
  • 1 Breadboard
  • Some male to male connector leads (~20 or so)
  • A 5v-6v battery power supply (4 AA batteries is borderline, I would recommend an RC pack or something, it needs to supply a good amount of power)
  • A 9v battery (for the arduino)

Step 2: The Circuit

Build the circuit above. Also I would recommend extending the leads on the photo resistors because you will connect them to the tuner very soon. Same applies for the servo if you are mounting your arduino a long way from the tuning slide on the trombone.

Step 3: Programming the Arduino

Upload this code to your arduino:

Feel free to modify it and tell me how I can improve on it.

Step 4: Attaching the Servo to the Trombone

  • Find a position for your servo on the trombone (a place where you can strap it on securely and reach the tuning slide)
  • strap the servo to the trombone (I used Velcro (not actually sticking the Velcro to the trombone), pad your servo first) (the servo should be strapped in very securely)
  • extend the servo arm so it can reach the tuning slide (I used a coat hanger, bent it at the end like a candy cane to grab the tuning slide and used a Velcro loop to secure it)
  • I put a piece of metal on the side of the servo to brace it against another pipe for extra support.
  • the bottom of the servo is a great place to put the Arduino's 9v battery
  • watch the video if you are confused

Step 5: Attach the Tuner to the Circuit

  • Hot glue the photo resistors to the LED lights on the tuner
    • The photo resistors attached to A0 and A1 go to the two sharp LED's
    • The photo resistors attached to A2 and A2 go to the two flat LED's
  • I stuck the breadboard circuit on top of the tuner to conserve space

Step 6: Attach the Circuit to the Trombone

  • strap the circuit to the trombone (again I used Velcro (again don't stick it directly to the trombone))
  • feel free to make it look nicer than mine
  • Hook up the servo and turn it everything on
  • I do not have a battery pack in any photos right now because I currently don't have a working one, so I am using a wall power supply (that's what I used in the video)
  • The circuit diagram shows how to connect the battery pack. Attach it to the trombone just like you attached the circuit and tuner
  • enjoy being the envy of your friends and effortlessly tuning your trombone

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    3 years ago

    Have you thought about using a piston instead of the servo?