A Single Octave 32 kHz Auditory Output Device

By: Erick Ruiz and Jeffrey Rollman

Research Problems:-Can a PSoC device be programmed to allow for auditory output?

-Is it possible to create a workable external CapSensing device that can overcome issues

associated with accuracy, signal loss and wiring difficulties?

-How can reliable pin connections be maintained with the large number of pins needed?

Abstract:The PSoC (Programmable System on Chip) device is a highly adaptable circuit board that can be programmed to allow for complete usage of the various onboard components. A PSoC device can be programmed for auditory output if it has the right components installed. The CY8C24894-24FLXI PSoC board contains a buzzer which allows for use of the board as an auditory output device. Additionally, the board includes a CapSense (Capacitive Sensor) component. This CapSense component includes touch sensitive buttons along with a slider which enable the input end of the project. Utilizing a CY3214 device, an octave of a piano keyboard can be simulated. The base of the program was written in C programming language on Cypress Semiconductor’s PSoC Designer 5 software. Initially, the program was written to work with only one board, allowing one full octave. However, with some modification, the C code can be modified successfully to allow two boards to connect and utilize both CapSense components. In addition, with even further development and more research, the board was able to be connected to external CapSense buttons that would serve as keyboards for the full octave to be outputted and also including a “whammy” slider for whammy effect on notes. With much testing and debugging, the device output was successful, with the CapSense components utilized to allow for a single full octave, including sharp and flat notes. Since the board was apt for that kind of customization, we tested it to see if an amplifier would have sustained. The amplifier sustained and the output was significantly cleaner. The board, with further programming, has the capability to play full songs with the amplifier. This application of the PSoC device is very promising for future embedded systems design as it demonstrates the feasibility of user friendly entertainment devices with flexible inputs and outputs. The PSoC is a revolutionary device that if used for specific uses, may surpass the dominance of multi-purpose personal computers.

UCSD COSMOS 2008Cluster 1: Adventures in Embedded Computer Systems

August 2, 2008

Hypotheses:-PSoC Designer 5.0 can be used to program a digital entertainment device-An external CapSensing device can be created on Plexiglas acrylic-Input from CapSense can create an output of varying sounds from PSoC circuit board

Hardware Used:-PSoC CY3214 circuit board

-Auditory amplifier

-Copper electric tape

-Assorted wires and capacitors

-Acrylic Plexiglas boards

-MiniProg programming device

Software Used:-Cypress Semiconductor’s PSoC

Designer 5.0 (C programming language)

-Cypress Semiconductor’s PSoC

Programmer

-A Windows computer

Acknowledgements:Thank you to the following:

-Professors: Rajesh Gupta Choon Kim

-Teacher Fellow: Shirley Miranda-T.A.s: Arash Arfaee

Bridget Benson-COSMOS staff

Purpose of Project:-Create a digital entertainment device using the PSoC circuit board-Create a user friendly interface for device operation-Ultimate Motivation: PSoC circuit board is relatively low cost and can serve as a universal platform for future consumer devices

Conclusion:The PSoC board was successfully able to support CapSense buttons and an 8-bit Pulse Width Modulator (Auditory Output.) The PSoC CY824094 EVAL board was able to support two sliders and had enough space for two more buttons. This board is not suitable for more than one octave at a time. The external CapSense buttons had significant noise and are extremely sensitive to each other and length. Some of the CapSense buttons had to be assigned to different port’s pins in order to have them all working. The number of components and the number of CapSense buttons were inversely proportional to each other; the more components placed, the less could be used for CapSense buttons. The pins were assigned logically to position the wires so they would not touch each other or else interference occurred. The wires were then soldered to the copper tape and the copper tape was attached to the eight-inch acrylic sheet. The acrylic sheet is non conductive, thus allowing for capacitive sensing to work. This board sustained all the external CapSense buttons and the auditory output.

The completed CapSense keyboard coupled with PSoC CY3214 circuit board.

Procedures:

Possible Further Applications:A CapSense electric guitarcan be created after over-coming wiring issues.

An early prototype ofthe CapSense device

The final CapSense keyboardwith PSoC circuit board