2023-06-07 01:57:40 +00:00
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#+title: Audio Input and Volume Control
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[[file:pcb.png]]
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* Features
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- Switches between three external inputs, outputting through the 3.5mm LINE OUT
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jack.
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- Volume control and input switching can be done using the pressable dial on the front
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- Current status is displayed on a 128x32 OLED display
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- Can be fully controlled via Home Assistant as an [[https://www.home-assistant.io/integrations/mqtt/][MQTT-discoverable]] device.
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* Firmware
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** Configuration
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Create a file named =settings.json= in the project directory with WiFi and MQTT
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connection information.
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#+begin_src js
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{
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"wifi": {
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"ssid": "MY-SSID",
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"password": "my-wifi-password"
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},
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"mqtt": {
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"broker": "192.168.1.123",
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"prefix": "digital-audio-switch"
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}
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}
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#+end_src
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** Deploying
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Connect the ESP32 to your computer. If you haven't already, [[https://micropython.org/download/esp32/][flash it with the
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latest version of MicroPython]], and ensure you have [[https://docs.micropython.org/en/latest/reference/mpremote.html][mpremote installed]].
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Running =make= will install dependencies and copy the code and configuration to
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the ESP32, resetting it when done.
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* Circuit Design
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The schematic and board layout can be found in the [[file:kicad/][kicad]] folder.
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* Case
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2023-06-17 05:17:24 +00:00
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The 3D-printable case is built using FreeCAD and can be found in the [[file:freecad/][freecad]]
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folder. It is divided into a top and bottom piece. The PCB is affixed using four
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M3 threaded inserts and 6mm M3 bolts, the case is assembled using 2 M3 threaded
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inserts and 2 10mm M3 bolts.
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