The Player Guitar Advised by T Baird Soules Team members: Joshua Libby, Stephen Monska, Simon Leung, Robert Williams

20 October, Outline  Background and Motivation  Deliverables of Design Project  System Block Diagram  MIDI Tablature  Player Guitar Mechanics Fretting Strumming Guitar Design Alternatives  Power  Product Cost  Q&A

20 October, Background and Motivation Learning how to play guitar is not an easy task for most. Plucking the strings at the right tone could be hard enough as is, but executing the techniques to silence, strum, dampen, and slide on the guitar as well could cause some problems. If only there was a way to play the guitar without having to spending months or even years to learn it. Our proposed ‘Player Guitar’ will attempt to solve this problem. It will be able to channel a person’s untapped guitar potential by having a device that will play the guitar for them. The user would be allowed to input files to the guitar, thus allowing the person to not worry about the semantics of how to play the guitar and spend more time on other factors, such as the composure of music.

20 October, The Design Designing a machine to play the guitar chords properly  Will be able to play a predefined music file  It will have the ability to pluck/slide/dampen Plucking will be accomplished using servos over the sound hole Sliding and Fretting will be accomplished using stepper motors and solenoids to hold down the strings To dampen strings, a solenoid with an eraser-like material at the end that silences the strings  The input will be coming from the MIDI Guitar Tablature Display that can be read in real time MIDI Guitar Tablature Display reads in a MIDI signal and outputs the appropriate finger placement on LEDS We plan to rework the former project to drive the input of our project, telling our machine where to place its “ fingers ” Background and Motivation

20 October, Deliverables of Design Project A working prototype will be completed for demonstrational purposes. This prototype should be able to play an audible sound from the guitar. There will be full documentation of how to use the Player Guitar, along with examples of how to work the user interface and pre- designed music files for demonstration purposes.

20 October, Deliverables of Design Project User Interface  The user interface will be done through the MIDI Guitar Tablature Display. It will consist of a 4x20 alpha (LCD Screen) and an optical encoder that serves both as a button and a selector switch. This display is controlled by a PIC 16 and was designed to change the mode of the main PIC as well as the settings. The mode of the PIC was used to change to an instrument other than a guitar, so it will not be changed in our project. The settings can be altered to change to any of the 16 different channels MIDI format uses. Input  The input will be from the MIDI Guitar Tablature Display that will read in a MIDI signal and calculate where the finger placements will be on the LEDS. These finger placements will be sent to the processor, which will know where to locate the frets and communicate that to the stepper motors. Output  The output will be the sound created by the mechanical fretter and strummer. The strumming will be done by servos and silencer solenoids that receive a single from the processor. The fretting will be done by the moving stepper motors. Acceptance Tests  The system must be properly converting the inputs from the MIDI Guitar Tablature Display and outputting it to the stepper motors.

20 October, Power: | Mechanical: | Signal: | System Block Diagram Guitar Power Stepper Motor Springboard Stepper Motor Springboard Stepper Motor Springboard Stepper Motor Springboard Stepper Motor Springboard Stepper Motor Springboard x6 Strum solenoids X6 Silence solenoids 5 V Music Tablature AVR Processor 24 V and 5 V MIDI Interface

20 October, MIDI Tablature  What it can do: Receive one channel of MIDI data and display the message in a 6x25 LED matrix representing the fret board of a guitar. Receive six channels of MIDI input, one from each string of a played guitar, and display the message in the LED matrix which will exactly describe the fingering of the guitar being played.  What it can do for us: It will serially drive the input of our AVR processor chip with the selected notes via SPI data.

20 October, MIDI Tablature  Uses an two 8-bit PIC processor One for a user interface to configure the settings. One for the main processor.  Forward the SPI Data by altering the.asm files from the LEDs to the AVR chip. PIC 18 Data Ready Bit Data Received Bit Status Bit Data Bit DATA Ready Bit 1 – Set by PIC16 to indicate that data is ready to be read by the PIC18. DATA Received Bit 1 – Set by PIC18 to indicate that data has been received. Status Bit 0 – FUNCTION is selecting the Mode of the device. 1 – FUNCTION is selecting the Setup of the device Data Byte If Status Bit = – Standard Mode – Octave Mode – Shadow Mode If Status Bit = – Channel – Channel – Channel – Channel 4 Etc. Specifications SPI Data To LEDs

20 October, MIDI Tablature: Block Diagram LED DRIVER LIQUID CRYSTAL DISPLAY 48 LED’S MIDI IN MIDI THRU 48 LED’S OPTICAL ENCODER USER INTERFACE PIC LED DRIVER AVR Processor MIDI PROCESSING PIC Retrieve from SPI From each LED with Ribbon Cables

20 October, Guitar Power Combined System Block Diagram Stepper Motor Springboard Stepper Motor Springboard Stepper Motor Springboard Stepper Motor Springboard Stepper Motor Springboard Stepper Motor Springboard x6 Strum solenoids X6 Silence solenoids 5 V Music Tablature AVR Processor LIQUID CRYSTAL DISPLAY MIDI THRU USER INTERFACE PIC MIDI IN OPTICAL ENCODER MIDI PROCESSING PIC Power: | Mechanical: | Signal: | 24 V and 5V

20 October, Player Guitar Mechanics Stepper Motors Spring Boards Strum Solenoids Gilmore Belts Silencer Solenoids Fretter Strummer

20 October,  Six stepper motors turn six gilmore belts  Since the motor is larger than belt, three will be placed on both sides of the bar stock  As the belt moves, it drags the spring boards over the strings to the appropriate position Stepper Motors Player Guitar Mechanics: Fretting

20 October, Player Guitar Mechanics: Strumming  Servos are controlled through Pulse Coded Modulation The length of a pulse expected ever 20 ms determines how far the servo turns  Placed over the string, the servos moves back and forth, in a 180 degree motion, hitting the string Strum Servos

20 October, Player Guitar Mechanics: Strumming Silencer Solenoids  Attach eraser or rubber material onto solenoids. When the solenoids push down onto string it will silence their sound.  These silence solenoids will be attached near the sound hole of the guitar with the servos, but could work anywhere past the frets on the guitar strings

20 October, Player Guitar Mechanics: Guitar Design Alternatives  If there is not enough room between the strings of the neck of the guitar Use less strings on the neck  This would either limit notes available, or require more necks and/or guitars Widen neck of guitar  Would lose acoustics, so may need to be implemented as an electric guitar, which would add the overhead of adding pickups

20 October, Power Power: | Power Stepper Motor Springboard Stepper Motor Springboard Stepper Motor Springboard Stepper Motor Springboard Stepper Motor Springboard Stepper Motor Springboard x6 Strum solenoids X6 Silence solenoids 5 V AVR Processor 24 V and 5 V  At least two power sources 24v standard amount for most stepper motors and solenoids Isolation the power to the processor

20 October, Product Cost  Estimated costs for electronics: Stepper Motor = $2 x 6= $24 Solenoid/Servos = $4 x 18 = $72 Guitar* = $0 x 4= $ 0 Total $96  This leaves plenty of money in our budget for getting a processor and handling any additional parts required. *: Three Guitars were obtained for free and one pizza box guitar was made at almost no cost to use in testing.

20 October, Question & Answer Stepper Motors Spring Boards Strum Servos Gilmore Belts Silencer Solenoids Fretter Strummer