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Physical Computing: TV Volume Regulator

Physical Computing: TV Volume Regulator

In my physical computing class at CMU, we had the opportunity to work with a group of older people who attend OSHER Lifelong Learning Institute at Carnegie Mellon University. We collaborated with Lois, one of the OSHER students, and after an in-house interview where we discussed her needs and daily routine , we designed a volume regulator for her television. Often at night, when she watches TV with her husband Irv, the volume of the commercial is much louder than the volume of the regular TV program.  To solve this problem,  I decided to create a device that uses IR signals to interact with her TV.  When the TV gets too loud the device automatically turns down the volume. After 30 seconds, or by pressing a button, the device is able to turn the volume back up.

The device is designed to sit on the table in Lois’ den positioned directly in front of the television. The device will listen and if the sound that it hears is continuously above a threshold for a period of time, it will send IR codes to the TV to lower the volume.  After 30 seconds, the TV will send signals to raise the volume back up, presuming that the TV commercials have ended and the regularly scheduled TV program is back on.

 
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Using the knob, Lois can change the threshold of the volume that she would like the TV to be set to. The button on top, is in some ways an override button. If for some reason the volume is lowered due to background noise, or the commercials end early, Lois can press the button to switch it to the other state. The device uses a 5V cable to connect to power and has a rocker switch to turn the device on/off.

Device as volume threshold is set: NeoPixel illumination indicates the volume threshold as the knob is turned

Device as volume threshold is set: NeoPixel illumination indicates the volume threshold as the knob is turned

Device as volume is being lowered: NeoPixel flashes green

Device as volume is being lowered: NeoPixel flashes green

Device as volume is being raised: NeoPixel flashes red

Device as volume is being raised: NeoPixel flashes red

Pushing the button on top to lower the volume, the NeoPixel flashes green to indicate that signals have been sent to the TV to lower the volume

Pushing the button on top to lower the volume, the NeoPixel flashes green to indicate that signals have been sent to the TV to lower the volume

Pushing the button on top to raise the volume, the NeoPixel flashes red to indicate that signals have been sent to the TV to raise volume again

Pushing the button on top to raise the volume, the NeoPixel flashes red to indicate that signals have been sent to the TV to raise volume again

Adjusting the knob on the device to change the threshold of the volume, NeoPixel adjusts to serve as a visual indication of what the threshold is.

Adjusting the knob on the device to change the threshold of the volume, NeoPixel adjusts to serve as a visual indication of what the threshold is.

 
IR Transmitter: The clear acrylic is meant to allow the IR transmitter to send the signals, and since IR cannot send signals through opaque acrylic we decided to use clear.

IR Transmitter: The clear acrylic is meant to allow the IR transmitter to send the signals, and since IR cannot send signals through opaque acrylic we decided to use clear.

Knob and Neopixel: The NeoPixel ring is a visual indication of what the device is doing: Lois wanted green to indicate that the volume is being lower, and red to indicate that volume is being raised. The white gives a visual representation of the volume—the knob is designed for ease of adjustment of volume.  Button: Button on top that can be pushed by Lois to change what signals the IR transmitter is sending

Knob and Neopixel: The NeoPixel ring is a visual indication of what the device is doing: Lois wanted green to indicate that the volume is being lower, and red to indicate that volume is being raised. The white gives a visual representation of the volume—the knob is designed for ease of adjustment of volume.

Button: Button on top that can be pushed by Lois to change what signals the IR transmitter is sending

Rocker Switch: Turns the device on/off without having to unplug the device

Rocker Switch: Turns the device on/off without having to unplug the device

5V input: in order to allow Lois to use this in her den, we wanted to connect to a power outlet

5V input: in order to allow Lois to use this in her den, we wanted to connect to a power outlet

Opened device: The wiring and the internal components of the device. Close up of internal electronics—notice the placement of the two breadboards: one is for IR transmitter and sound sensor while another is placed for the potentiometer knob above the Arduino.

Opened device: The wiring and the internal components of the device. Close up of internal electronics—notice the placement of the two breadboards: one is for IR transmitter and sound sensor while another is placed for the potentiometer knob above the Arduino.

CAD model in Fusion 360

CAD model in Fusion 360

Renderings of Final Product

Front face of device: wood and plastic material mimics the look of some of Lois’ radio and other devices in her loft

Front face of device: wood and plastic material mimics the look of some of Lois’ radio and other devices in her loft

3/4 view with top button hole allowance

3/4 view with top button hole allowance

Back side of device with rocker switch hole and 5V input allowance

Back side of device with rocker switch hole and 5V input allowance

 

Process

We began the project with an in-house interview with our client, Lois. At the initial meeting, we wanted to gain some insight into what our client, Lois wanted for her assistive device. We met Lois at her home on Monday, March 25, at 9:45 AM.

Lois’ cat! A frequent visitor of the den, often accompanying Lois & Irv’s TV adventures.

Lois’ cat! A frequent visitor of the den, often accompanying Lois & Irv’s TV adventures.

Notes taken during initial meeting with Lois

Notes taken during initial meeting with Lois

 

First Prototype

After interviewing Lois, we determined that we would focus on designing a TV volume regulator for Lois and Irv’s den.  A constant issue that Lois runs into is that when she is watching TV, as the commercials come on, the volume increases so much that Lois has to lower the volume using the remote.

This first prototype used an LCD screen and did not feature the button in the final product. After speaking with our client, she described the benefits of having the button added to the top of the device.

First prototype mainly tested out electronics and code

First prototype mainly tested out electronics and code

10k Potentiometer for volume threshold and IR transmitter for sending codes

10k Potentiometer for volume threshold and IR transmitter for sending codes

Audio sensor used to identify loudness

Audio sensor used to identify loudness

 

PROCESS OF first PROTOTYPE

Some places we considered for the placement of the device was the small space next to the television. However we decided that if Lois or Irv wanted to change the threshold of the volume, the space next to the TV’s speaker would be inconvenient to access. We then considered the coffee table which served as a good compromise to both the proximity to the TV as well as the accessibility to Lois and Irv. However, Lois and Irv preferred not to have the device on the coffee table, so we dismissed that idea. In the end we decided to move the placement of the device to the back table, due to the ease of access. One issue we do expect is the sound detection as well as the reliability IR transmitter, however once that issue arises, we will work that out with Lois.

1. Placement of Device: Panorama shot of Irv and Lois’ den to understand placement of the TV volume regulator

1. Placement of Device: Panorama shot of Irv and Lois’ den to understand placement of the TV volume regulator

IR Code Reading: Using Lois’ remote to find her remote’s IR code, we recorded her IR code for the different buttons

IR Code Reading: Using Lois’ remote to find her remote’s IR code, we recorded her IR code for the different buttons

Testing IR transmitter + receiver, button is used to send code to the IR receiver. Sound detector is used to detect volume from TV

Testing IR transmitter + receiver, button is used to send code to the IR receiver. Sound detector is used to detect volume from TV

Lois’ TV Remote

Lois’ TV Remote

Sound detector issues: The sound detector we were using wasn’t sensitive/reliable enough to detect the volume of the television, we eventually decided to switch to another sound detector

Sound detector issues: The sound detector we were using wasn’t sensitive/reliable enough to detect the volume of the television, we eventually decided to switch to another sound detector

 

PROCESS OF final prototype

Working with the smaller NeoPixel and seeing the different effects it could have in the library (Look at the reflection on the laptop screen, pretty cool!)

Working with the smaller NeoPixel and seeing the different effects it could have in the library (Look at the reflection on the laptop screen, pretty cool!)

Working with the Neopixel and combining it with the code for the sound detector

Working with the Neopixel and combining it with the code for the sound detector

Lasercut cardboard templates to figure out dimensions of final product

Lasercut cardboard templates to figure out dimensions of final product

After looking at the two cardboard mockups, we decided to work with the smaller model size—determining it was easier to print as well as more fitting in Lois’ den

After looking at the two cardboard mockups, we decided to work with the smaller model size—determining it was easier to print as well as more fitting in Lois’ den

Working with the NeoPixel and figuring out the optimal placement for it within the device

Working with the NeoPixel and figuring out the optimal placement for it within the device

Bondo to smooth out rough parts of the print

Bondo to smooth out rough parts of the print

Spray painted the piece to cover up the Bondo

Spray painted the piece to cover up the Bondo

Bondene’d the weaker parts of the print (especially the NeoPixel print area to ensure that the part would not crack

Bondene’d the weaker parts of the print (especially the NeoPixel print area to ensure that the part would not crack

Final Product

Final Product