Materials

  • PVC enclosure
  • audio codec VS1053
  • 20x4 LCD screen with Uart backpack
  • plastic standoffs M3
  • 26 AWG wire
  • 3000 mAh external battery with microUSB supply
  • (4) 4-pin push button
  • 1 3-pin rotary POT with knob cap
  • SPDT power switch
  • SJOne microcontroller (LPC) running ARM cortex M4 microprocessor
  • About the design

    A PVC enclosure and plastic standoffs were used to reduce weight.


    A rotary potentiometer was used to replicate a volume knob, while 4-pin push buttons were used for device control.


    The LCD screen, audio codec and SJ One board use a +5V input being fed from a +5V power rail. A +5V micro usb breakout is used to supply a constant +5V from a 3000mAh power bank.


    Since pins on the SJ One board are only +3.3V tolerant, a +3.3V power rail is used in conjunction to avoid extra components. Each button and potentiometer use +3.3V input from the +3.3V rail being sourced by the SJ One board.


    Connections were made by soldering each component on the PCB for the button interface, while 30 AWG wire was chosen for wire wrapping the interfacing the screen, microprocessor and codec.