KnobSwitch

What it is

KnobSwitch is a minimal entertainment center controller. One big-ass knob for volume control and one selector switch for input source.

What it does

Gives you instant, simple selection of your input source and volume control. Communicates to your equipment via BLE – each piece of equipment will need a BLE server and interface to the control port.

I have a Marantz SR8500 and an LG OLED55C7P, both of which have serial ports. Yes, you could use IR but I want this thing to be reliable, i.e. closing the control loop with feedback from the equipment. Yes, you could useĀ  WiFi to do this but that introduces tons of lag versus a local connection.

The Marantz receiver is lovely but scrolling through all the inputs using the big knob on the front is maddening and slow. Using the remote is evenĀ more maddening because it has a thousand tiny buttons, and I recently installed the receiver into a rack so it’s no longer in the line of sight.

The LG TV is flawless in every way and cures cancer, but I’d like to have one place to control both the audio volume and the overall input source. This requires fusion of audio and video source switching.

What it’s made of

  • BLE MCU
  • Rotary encoder without detents
  • Rotary switch with stiff detents
  • Simple indication of input source, like an LED next to a static label
  • Aluminum enclosure with smooth top
  • Lithium-ion battery
  • PCB designed in EAGLE
  • Firmware

Resources

  • http://www.mouser.com/ProductDetail/Alpha-Taiwan/SR2511F-0304-19R0B-E9-N-W-159/
  • https://www.parts-express.com/large-aluminum-tapered-receiver—amp-knob-11-matte–240-2222
  • https://www.parts-express.com/large-aluminum-receiver—amplifier-knob-158-matte–240-2218
  • https://www.digikey.com/product-detail/en/cui-inc/C14N32P-C3/102-1918-ND/2037018
  • https://www.eevblog.com/forum/projects/smooth-rotary-encoder/
  • http://www.ebay.com/itm/Silver-Aluminum-PCB-instrument-Box-Enclosure-Case-Project-DIY-110-110-40mm/112121491662
  • http://www.ebay.com/itm/New-Aluminum-Box-Enclosure-Case-Project-electronic-DIY-110-74-22MM-L-W-H/171447382317
  • http://www.ebay.com/itm/Aluminum-Box-Circuit-Board-Enclosure-Case-Project-Electronic-for-DIY-100x74x29MM/131656807607
  • http://www.ebay.com/itm/HM-10-BLE-Bluetooth-4-0-CC2541-CC2540-Serial-Wireless-Module-Arduino-Android-IOS-/171988143980
  • http://runawaybrainz.blogspot.com/2013/08/avr-attiny-2313-v-usb-media-volume.html
  • http://www.nkkswitches.com/products/illuminated-pushbutton/#gref

UFanders

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