Tap-Tap environmental controls unit

Tap-Tap Environmental Controls Unit April Hiscox’, Brooke Hallowel12,John D. Enderle’ ‘University of Connecticut Department of Electrical and Systems Engineering 260 Glenbrook Road, Storrs, CT 06269-2157

’School of Hearing and Speech Sciences Lindley Hall 208 Ohio University Athens, OH 45701

Abstract-Certain individuals with Cerebral Palsy communicate using a head-mounted device wherein they can press computer keys, etc. The Tap-Tap environmental controller adapts this method of communication into a device that facilitates household appliance control via touchpad circuitry.

allows control of several appliances and room lighting through a simple tapping motion. The ECU is, in effect, a universal remote with extremely large buttons. The unit itself mounts vertically on the client’s nightstand to allow for complete control of his surrounding bedroom environment.

I. INTRODUCTION

A. User-lnterface/Touch Switches

The work described in this report is part. of a National Science Foundation’ sponsored effort to have student engineers at universities throughout the US design and construct devices for persons with disabilities [l]. Once the project is completed, it is given to the person with disabilities (client) as a gift to use to improve their life. Cerebral Palsy (CP) is a neurological condition that affects a person’s muscle control. There is no cure. It is caused by an injury to the brain before, during or shortly after birth. There are many different types of CP as well as levels of severity. In all cases, however, there is damage to muscle tone, which causes jerky, wobbly or difficult movements for the affected individual. The client desires independence while listening to music or watching television. His activities are limited to those that require no movement other than the motion of his head. He cannot, however, control these appliances. The Tap-Tap Environmental Controller allows the client to control appliances by utilizing a touchpad operated device from his bed. 11. DESCRIPTION The Tap-Tap Environmental Control Unit (ECU) provides reliable remote control of a TV, VCR, Stereo system and bedroom lights achieved through infrared technology. Light control is accomplished using radio frequency transmission, and is controlled at the outlet level for the lamps in the room. The device is easy to use and upgradable for future additions. There is manual override capability for control of the lights in the room. The device has adaptive switching technology to allow minimal physical effort on the user end. The Tap-Tap ECU consists of three physical units. The first unit is a control panel and the other two are identical switching units for each of the lights to be controlled. The key feature of the device is its touchplate interface, which I The work carried out in this project was supported by the National Science Foundation under grant number BES 98 12042.

0-7803-6341-8/00/$10.0002000 IEEE

There are many different methods of user input. This product is special in the touchplate design that it utilizes. Touch switches operate on different principles of the human body. Some rely upon the skin resistance of an individual to complete a circuit, while others rely on the body’s inherent capacitance to control the circuit. The touchplates themselves are etched onto a printed circuit board, where each switch is approximately three inches long by three inches wide. This provides the client a large enough surface area to tap without requiring too much accuracy. The output of the switches is connected directly to the switches on a commercial remote via ribbon cables.

B. Appliance Control The appliance control unit consists of the connections between the commercial remote control and the touchplate interface. Ribbon cables are utilized to achieve this function. When the user taps a touchplate, the command is sent to the commercial remote where it is processed and sent to the appliances via an infrared transmission. The commands are “taught” to the remote through its learning function. The remote itself provides the memory to map the commands to the correct inputs. The remote used for the ECU is the Home Theater Mastera SL-9OO0, made by Universal Remote Control, Inc. This remote control has both learning and preprogrammed functionality. It receives input from an existing remote and learns the necessary codes to operate it. C. Light Control The light control unit is used to control the lights in the bedroom. The lights are turned on and off by tapping one of the buttons on the touch panel. This device is controlled through RF circuitry. There are three separate units involved in controlling the lights. One transmit unit, housed within the main control panel, sends the signal, while two separate

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E. Packaging

Stereo Power

11

Stereo Function

11

Fast Forward

II

The Tap-Tap ECU consists of three separate physical structures. There are two switching units, which are approximately the size of a standard wall socket, with a depth of 3 to 4 inches. The third structure is the control panel which houses the touch switches and all circuitry to control the lights. A front view of the panel is shown in Figure 1. The panel is approximately 16" square, and mounts vertically on the nightstand next to the client's bed. The three switches along the left-hand side select the device to be controlled. The remaining switches control the different functions of the devices. The commercial universal remote has a punch through feature, which allows the client to control the volume on the TV while the VCR is being operated. The two empty switches are used as programming buttons.

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CONCLUSION 15.75"

4

.Fig. 1.

ECU control panel

receive units, one at each light, receives, decodes and reacts to the signal. Light control is achieved by tapping on either touch switch for a total of two available touch switches in the transmit unit. When.one switch is selected, a certain output sequence is sent, and if the other is selected, a different sequence is sent. The receive unit contains a decoder circuit as well as a power switching circuit. On the decoder side of the circuit, there is a check to see if the signal being received is the signal to activate the switching unit. Both receivers receive all of the signals sent by the transmitter, so this check is necessary to distinguish between the two lights. The FW components used for this device are the LC series from Linx, technologies. A quarter whip antenna also from Linx technologies is used for these circuits for easier tuning. A general diagram of the light controls is illustrated in Figure 1.

The Tap-Tap ECU is a unique way of allowing a person with physical disability to gain some independence. Although tailored to an individual's needs, the ECU is easily adapted for others with similar disabilities and situations. The ECU utilizes the widely popular concepts of the universal remote and adapts it to be used through a simple touch. By removing unneeded functions, this device is more affordable than those units commercially available ACKNOWLEDGEMENT The authors wish to thank John Fiket and Rushi Guan for professional design help and useful circuit/IC information, and Sue Ellen Miller for the client referral.

D. Switching Unit The switching unit utilizes a solid state relay switch between the lamp and the 110V wall supply. This solid state relay is combined with an optical isolated triac driver with zero crossing. The zero crossing is necessary to avoid a current surge when switching occurs. When a 5-volt signal is received by the triac, current is allowed to flow and the lamp is turned on. The unit is plugged into the wall socket, and the lamp is plugged into the unit. If the light switch is turned off manually, the light will go off, and the remote control option will be disconnected. There are two switching units in the ECU.

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REFERENCE 1. Enderle, J.D., Pruehsner, W., Hallowell, B., First Year Experience at the University of Connecticut with NSF Design Projects to Aid Persons with Disabilities. Biomedical Sciences Instrumentation, 1999, 35: 253-258.