TeensyBat diy batdetector


Welcome to my Teensybat page. I am Edwin Houwertjes an enthusiastic electronics hobbyist working with the TeensyBat, a Teensy based d.i.y. bat detector for a few years now. (Teensy is a development board made by PJRC) It takes up a lot of my free time but this device is too much fun to keep just for myself.

I hope the help you build a detector like this TeensyBat using the information on this website.

Bat detector that shows received sound. od a common pipistrelle.

New PCB's (V0.8) available. 

I designed a second version of the Teensy 4.1 based PCB.  There is some space for a second microphone amplifier, specially for the people that want to play with the software and create a stereo version. The normal TeensyBat can be built with this PCB as usual, but the mic-in also connects to the line-in left signal, The extra TL972 opamp (IC3) can be placed to create the line-in right signal with the input pin next to the 3 microphone pads.  This is not a stereo version!. It just holds extra parts for people that want to try and write a stereo version of the software. The part numbering changed a bit but building it is exactly the same as the earlier PCB since all SMD parts are already mounted on the printed circuit board.



I did release the design and production files for the Teensy 3.6 based version, I'll keep these Teensy 4.1 based files for my self. 


Why Teensy 4.1? Well a huge advantage is the extra memory we can mount. It will give you a nice prerecord buffer that allows you to store about 4 seconds of sound that you just heard.


Keywords: bat, detector, batdetector, vleermuis, vleermuisdetector, teensy, time expansion, heterodyne, frequency division, frequentiedeler, ultrasoon, spu0410lr5h, spu0410lr5h-qb, zelfbouw, diy, homebrew, spectrogram, waterval, waterfall, classify,

Below you can add comments, if you like the site, the detector or the support you can write that here. Check out the rest of the site for parts (and partial kits) I am sharing. My e-mail can be found on the contact page. The comments below are one way notifications, not meant for discussion.

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Mike Richards
3 months ago

Thanks for sharing Edwin, this is a wonderful advanced bat detector. As an experienced constructor, I made a schoolboy error by not fully reading the instructions. My mistake was easily corrected but it would have been a completely trouble-free build if I'd followed Edwin's excellent instructions!!
My simple advice is to read the instructions thoroughly before you start.

3 months ago

Just built the v0.8 kit, works really well. Detected bats in my garden on first night of autorecord use. Thanks so much for sharing.

4 months ago

This is not really the place to start any discussion but to answer Toby, please check the backup battery. The cheap one euro stores often sell batteries that run out quickly but you wille end op with an empty back-up battery eventually someday and have to replace it. That is why the battery is in a socket, to be replaced quite easily. If your battery stil is fine (3V) check if that 3V still ends up at that single pin on the teensy (next to the long row of pins) .
About software for analysis, please have a look here, there is a nice list https://chirovox.org/resources_software.php
All free versions have limited functions, and demo's usually work one month. In that list I am missing the BTO Acoustic pipeline.

4 months ago

I built one (PCB 0.7) last christmas and have been using it quite a bit now the bats are out!. Followed build instructions carefully and it worked right out the box! The only issue I have is that the date / time does not survive power off / on cycle, so I have to reset each time. Currently using https://www.batlogger.com/en/products/batexplorer/ to analyse the bat recodings which is great, what do other people use?

Frank Märtin
5 months ago

I built the device and everything worked right away! The display graphics respond wonderfully. We look forward to the bat observations! Many thanks for developing and providing the kit!!!

Bart Mudde
10 months ago

I am curious for this detector. Because i used to be a radio amateur I built serveral radio's but with smd i have no experience. Do you deliver it as diy but with the smd on the board en what do you charge?

Frank F
a year ago

The seller was very kind and helpful regarding questions, extra parts, billing and shipping. I'm using the device every week since I bought it in December last year. Can definitely keep up with professional devices and never failed me before. I had some difficulties getting it to work because I am really bad at soldering but got it to work after a few hours.

Rob S
2 years ago

Edwin, I sit here with a freshly completed TeensyBat on my desk. It works fantastically and I'm very impressed by it. Bravo!

I am a bat worker in the UK and frequently use ~£900 bat detector units. This TeensyBat build is way cooler and has so many more features. I look forward to using it out in the field.

Thank you for creating this awesome project and making it publicly avaliable.

Edwin Houwertjes
2 years ago

Normally I do not write here but answering Thomas gives some idea about the developments.

Teensy 4.1 version boards are ordered, but production takes some time.
The Audioboard is still used. It provides extra gain setting and is also usefull for playback (connecting headphones) we will be using the audio board but it is integrated on the main board.
We do uses extra memory that can be soldered directly to the Teensy it is not used to help reducing "writing sounds" I helps us store sounds that already passed a few seconds ago.

The noises of the SD card writing can be reduced by separating Vin(Teensy) and input of te 3.3V LDO(IC2), and give each their own RC filter (ad an extra R10/C10 circuit)

2 years ago

I am quite happy with my teensyBat based on v0.2a. Would it be possible to come up with a new hardware version based on teensy 4.1 and without the need for the extra audio board (built-in ADCs only)? This would reduce the cost.
Would it also be possible to "record" the signal into a buffer for some time and save it later to the SD card? This would avoid noise coupling into the signal from SD card write operations.

Thank you so much for your effort to make this project available for a bat enthusiast like me.