μMoth is a micro-size, low-cost, full-spectrum acoustic logger, adapted from the original AudioMoth open-source design, while maintaining full compatibility with all versions of the existing firmware. 

  • EFM32 Gecko processor

  • Capable of recording at sample rates up to 384kHz

  • Records uncompressed WAV files to microSD card

  • Powered by one lithium ion battery

  • Analog MEMS microphone

  • Analog pre-amplifier with adjustable gain

  • Measures just 32 x 24 mm 

  • Weighs 5g

  • Configurable USB interface

  • Onboard real-time clock keeps track of time in UTC

  • Compatible with the standard AudioMoth's existing software

About the developer

μMoth was designed by Ruby Lee in partnership with Dr. Robin Freeman at ZSL and Al Davies at Arribada Initiative. The aim was to develop a smaller version of AudioMoth which could be used by researchers for animal-borne monitoring.


Ruby is an electronic engineer who took on the challenge of reducing the size of the original AudioMoth design, whilst maintaining the same functionality and quality. Ruby enjoys miniaturising PCBs and gets huge satisfaction from even removing just a millimetre from a design, unfortunately microSD cards are not micro enough, so she had to settle with a size of 32 x 24 mm. 

This is the first official open source developer of an Open Acoustic Devices design, taking the original AudioMoth design to create the tiny μMoth. Together with researchers at ZSL, Ruby will be putting the μMoth through its paces throughout 2020. 

Ruby Lee 

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