===== Interfacing =====
  * [[https://www.openacousticdevices.info/support/device-support/power-outputs/p-1/dl-60253e16fa4bba001743abf7|guidence on using GPIO pins]]
  * [[https://github.com/OpenAcousticDevices/AudioMoth-Project/wiki/AudioMoth-Library|Definitions and Interrupts]]
  * [[https://siliconlabs.github.io/Gecko_SDK_Doc/efm32gg/html/group__GPIO.html#gac954a361034e059b980964055f6d735a|Configuring Interrupts]]
  * [[https://www.silabs.com/documents/public/application-notes/an0012-efm32-gpio.pdf|setting GPIO pin mode (input/output/pullup on or off]] (see page 5)
  * [[https://github.com/OpenAcousticDevices/Application-Notes/blob/master/Using_AudioMoth_with_External_Electret_Condenser_Microphones.pdf|using an external microphone]]