π•pistrelle Bat Detector

FEATURES

The pipistrelle family consists of the handheld time-expanding / heterodyning detector pipistrelle mini, the static detector / ultrasound recorder pippyg and the 384kHz USB microphones Griff and Griff Mini.

Each can be built in quantities of 10 for well under £20 per item using inexpensive equipment readily available on Amazon. Griff and Griff Mini in particular do not even require the use of soldering irons or cutting tools, and not only make high-quality bat science devices but also make excellent introductions to surface-mount electronics assembly.

pipistrelle mini and pippyg offer high-end features previously seen only on high-cost equipment, despite being the lowest-cost bat recorders on the market.

pipistrelle mini - handheld active bat detector

Heterodyne detection
- Rhythm of bat calls is preserved
- Scans automatically for bat calls
- No manual tuning - "eyes to the skies" operation
Advanced "Time Expansion" mode reveals true nature of bat sounds
- Harmonic relationships of bat calls are preserved
- Slows down bat calls 16x or 10x (user-configurable)
Audio output over headphone socket
- Connect to external powered speaker to lead bat walks
10-LED real-time spectrum display
- indicates approximate frequency of calling bats
- More detail available via frequency speech synthesis
Auto-detect USB microphone mode
- When powered off then plugged into an iPhone or iPad, pipistrelle handheld detectors power up as 384kHz USB microphones for use with the Bat Detector app : apps.apple.com/gb/app/bat-detector/id6504186190

pippyg - passive bat detector

Records 384kHz / 16-bit wav files to microSD
- File size optimised for analysis by BTO Acoustic Pipeline
- Files timestamped and location-stamped
- Geolocation metadata stored in industry-standard "GUANO" format
- iOS / MacOS / Android app configures devices for recording
  - Sets up device ID
  - Date and time
  - Geolocation
Devices typically run for 4 to 7 days
- Based on measured performance using 2450mAh rechargeables
- Achievable run-time depends on number of recordings
Microphone option : when reflashed with pippyg-mic.uf2 the device operates as a 384kHz / 16-bit USB microphone when powered via USB

pippyg is powered by 3 AA batteries, pipistrelle mini by AAA
pipistrelle mini operates as a 384kHz USB microphones when powered from USB port

Designed for use with the iOS App Bat Detector

USB microphone is recognised by iOS, MacOS, Windows and Linux - does not yet work with Android

Suite of support tools provided both as C++ source code and as precompiled cross-platform binaries

Binaries are JavaScript for running in Node.js®, which is available for Microsoft, Apple and Linux
- Download Node.js® for your operating system here : https://nodejs.org/en
sonogram.js creates .jpg sonograms from a folder of recordings, and creates a .CSV of the latitude / longitudes of those recordings for uploading to Google My Maps, allowing you to visualize a bat walk
chirpwav.js creates .wav file to configure devices
patchpip.js modifies firmware images to support device re-flashing with custom behaviour